.

vendor/github.com/spf13/afero/.gitignore

@@ -0,0 +1,2 @@
+sftpfs/file1
+sftpfs/test/

vendor/github.com/spf13/afero/README.md

@@ -0,0 +1,442 @@
+![afero logo-sm](https://cloud.githubusercontent.com/assets/173412/11490338/d50e16dc-97a5-11e5-8b12-019a300d0fcb.png)
+
+A FileSystem Abstraction System for Go
+
+[![Test](https://github.com/spf13/afero/actions/workflows/test.yml/badge.svg)](https://github.com/spf13/afero/actions/workflows/test.yml) [![GoDoc](https://godoc.org/github.com/spf13/afero?status.svg)](https://godoc.org/github.com/spf13/afero) [![Join the chat at https://gitter.im/spf13/afero](https://badges.gitter.im/Dev%20Chat.svg)](https://gitter.im/spf13/afero?utm_source=badge&utm_medium=badge&utm_campaign=pr-badge&utm_content=badge)
+
+# Overview
+
+Afero is a filesystem framework providing a simple, uniform and universal API
+interacting with any filesystem, as an abstraction layer providing interfaces,
+types and methods. Afero has an exceptionally clean interface and simple design
+without needless constructors or initialization methods.
+
+Afero is also a library providing a base set of interoperable backend
+filesystems that make it easy to work with afero while retaining all the power
+and benefit of the os and ioutil packages.
+
+Afero provides significant improvements over using the os package alone, most
+notably the ability to create mock and testing filesystems without relying on the disk.
+
+It is suitable for use in any situation where you would consider using the OS
+package as it provides an additional abstraction that makes it easy to use a
+memory backed file system during testing. It also adds support for the http
+filesystem for full interoperability.
+
+
+## Afero Features
+
+* A single consistent API for accessing a variety of filesystems
+* Interoperation between a variety of file system types
+* A set of interfaces to encourage and enforce interoperability between backends
+* An atomic cross platform memory backed file system
+* Support for compositional (union) file systems by combining multiple file systems acting as one
+* Specialized backends which modify existing filesystems (Read Only, Regexp filtered)
+* A set of utility functions ported from io, ioutil & hugo to be afero aware
+* Wrapper for go 1.16 filesystem abstraction `io/fs.FS`
+
+# Using Afero
+
+Afero is easy to use and easier to adopt.
+
+A few different ways you could use Afero:
+
+* Use the interfaces alone to define your own file system.
+* Wrapper for the OS packages.
+* Define different filesystems for different parts of your application.
+* Use Afero for mock filesystems while testing
+
+## Step 1: Install Afero
+
+First use go get to install the latest version of the library.
+
+    $ go get github.com/spf13/afero
+
+Next include Afero in your application.
+```go
+import "github.com/spf13/afero"
+```
+
+## Step 2: Declare a backend
+
+First define a package variable and set it to a pointer to a filesystem.
+```go
+var AppFs = afero.NewMemMapFs()
+
+or
+
+var AppFs = afero.NewOsFs()
+```
+It is important to note that if you repeat the composite literal you
+will be using a completely new and isolated filesystem. In the case of
+OsFs it will still use the same underlying filesystem but will reduce
+the ability to drop in other filesystems as desired.
+
+## Step 3: Use it like you would the OS package
+
+Throughout your application use any function and method like you normally
+would.
+
+So if my application before had:
+```go
+os.Open("/tmp/foo")
+```
+We would replace it with:
+```go
+AppFs.Open("/tmp/foo")
+```
+
+`AppFs` being the variable we defined above.
+
+
+## List of all available functions
+
+File System Methods Available:
+```go
+Chmod(name string, mode os.FileMode) : error
+Chown(name string, uid, gid int) : error
+Chtimes(name string, atime time.Time, mtime time.Time) : error
+Create(name string) : File, error
+Mkdir(name string, perm os.FileMode) : error
+MkdirAll(path string, perm os.FileMode) : error
+Name() : string
+Open(name string) : File, error
+OpenFile(name string, flag int, perm os.FileMode) : File, error
+Remove(name string) : error
+RemoveAll(path string) : error
+Rename(oldname, newname string) : error
+Stat(name string) : os.FileInfo, error
+```
+File Interfaces and Methods Available:
+```go
+io.Closer
+io.Reader
+io.ReaderAt
+io.Seeker
+io.Writer
+io.WriterAt
+
+Name() : string
+Readdir(count int) : []os.FileInfo, error
+Readdirnames(n int) : []string, error
+Stat() : os.FileInfo, error
+Sync() : error
+Truncate(size int64) : error
+WriteString(s string) : ret int, err error
+```
+In some applications it may make sense to define a new package that
+simply exports the file system variable for easy access from anywhere.
+
+## Using Afero's utility functions
+
+Afero provides a set of functions to make it easier to use the underlying file systems.
+These functions have been primarily ported from io & ioutil with some developed for Hugo.
+
+The afero utilities support all afero compatible backends.
+
+The list of utilities includes:
+
+```go
+DirExists(path string) (bool, error)
+Exists(path string) (bool, error)
+FileContainsBytes(filename string, subslice []byte) (bool, error)
+GetTempDir(subPath string) string
+IsDir(path string) (bool, error)
+IsEmpty(path string) (bool, error)
+ReadDir(dirname string) ([]os.FileInfo, error)
+ReadFile(filename string) ([]byte, error)
+SafeWriteReader(path string, r io.Reader) (err error)
+TempDir(dir, prefix string) (name string, err error)
+TempFile(dir, prefix string) (f File, err error)
+Walk(root string, walkFn filepath.WalkFunc) error
+WriteFile(filename string, data []byte, perm os.FileMode) error
+WriteReader(path string, r io.Reader) (err error)
+```
+For a complete list see [Afero's GoDoc](https://godoc.org/github.com/spf13/afero)
+
+They are available under two different approaches to use. You can either call
+them directly where the first parameter of each function will be the file
+system, or you can declare a new `Afero`, a custom type used to bind these
+functions as methods to a given filesystem.
+
+### Calling utilities directly
+
+```go
+fs := new(afero.MemMapFs)
+f, err := afero.TempFile(fs,"", "ioutil-test")
+
+```
+
+### Calling via Afero
+
+```go
+fs := afero.NewMemMapFs()
+afs := &afero.Afero{Fs: fs}
+f, err := afs.TempFile("", "ioutil-test")
+```
+
+## Using Afero for Testing
+
+There is a large benefit to using a mock filesystem for testing. It has a
+completely blank state every time it is initialized and can be easily
+reproducible regardless of OS. You could create files to your heart’s content
+and the file access would be fast while also saving you from all the annoying
+issues with deleting temporary files, Windows file locking, etc. The MemMapFs
+backend is perfect for testing.
+
+* Much faster than performing I/O operations on disk
+* Avoid security issues and permissions
+* Far more control. 'rm -rf /' with confidence
+* Test setup is far more easier to do
+* No test cleanup needed
+
+One way to accomplish this is to define a variable as mentioned above.
+In your application this will be set to afero.NewOsFs() during testing you
+can set it to afero.NewMemMapFs().
+
+It wouldn't be uncommon to have each test initialize a blank slate memory
+backend. To do this I would define my `appFS = afero.NewOsFs()` somewhere
+appropriate in my application code. This approach ensures that Tests are order
+independent, with no test relying on the state left by an earlier test.
+
+Then in my tests I would initialize a new MemMapFs for each test:
+```go
+func TestExist(t *testing.T) {
+	appFS := afero.NewMemMapFs()
+	// create test files and directories
+	appFS.MkdirAll("src/a", 0755)
+	afero.WriteFile(appFS, "src/a/b", []byte("file b"), 0644)
+	afero.WriteFile(appFS, "src/c", []byte("file c"), 0644)
+	name := "src/c"
+	_, err := appFS.Stat(name)
+	if os.IsNotExist(err) {
+		t.Errorf("file \"%s\" does not exist.\n", name)
+	}
+}
+```
+
+# Available Backends
+
+## Operating System Native
+
+### OsFs
+
+The first is simply a wrapper around the native OS calls. This makes it
+very easy to use as all of the calls are the same as the existing OS
+calls. It also makes it trivial to have your code use the OS during
+operation and a mock filesystem during testing or as needed.
+
+```go
+appfs := afero.NewOsFs()
+appfs.MkdirAll("src/a", 0755)
+```
+
+## Memory Backed Storage
+
+### MemMapFs
+
+Afero also provides a fully atomic memory backed filesystem perfect for use in
+mocking and to speed up unnecessary disk io when persistence isn’t
+necessary. It is fully concurrent and will work within go routines
+safely.
+
+```go
+mm := afero.NewMemMapFs()
+mm.MkdirAll("src/a", 0755)
+```
+
+#### InMemoryFile
+
+As part of MemMapFs, Afero also provides an atomic, fully concurrent memory
+backed file implementation. This can be used in other memory backed file
+systems with ease. Plans are to add a radix tree memory stored file
+system using InMemoryFile.
+
+## Network Interfaces
+
+### SftpFs
+
+Afero has experimental support for secure file transfer protocol (sftp). Which can
+be used to perform file operations over a encrypted channel.
+
+### GCSFs
+
+Afero has experimental support for Google Cloud Storage (GCS). You can either set the
+`GOOGLE_APPLICATION_CREDENTIALS_JSON` env variable to your JSON credentials or use `opts` in
+`NewGcsFS` to configure access to your GCS bucket.
+
+Some known limitations of the existing implementation:
+* No Chmod support - The GCS ACL could probably be mapped to *nix style permissions but that would add another level of complexity and is ignored in this version.
+* No Chtimes support - Could be simulated with attributes (gcs a/m-times are set implicitly) but that's is left for another version.
+* Not thread safe - Also assumes all file operations are done through the same instance of the GcsFs. File operations between different GcsFs instances are not guaranteed to be consistent.
+
+
+## Filtering Backends
+
+### BasePathFs
+
+The BasePathFs restricts all operations to a given path within an Fs.
+The given file name to the operations on this Fs will be prepended with
+the base path before calling the source Fs.
+
+```go
+bp := afero.NewBasePathFs(afero.NewOsFs(), "/base/path")
+```
+
+### ReadOnlyFs
+
+A thin wrapper around the source Fs providing a read only view.
+
+```go
+fs := afero.NewReadOnlyFs(afero.NewOsFs())
+_, err := fs.Create("/file.txt")
+// err = syscall.EPERM
+```
+
+# RegexpFs
+
+A filtered view on file names, any file NOT matching
+the passed regexp will be treated as non-existing.
+Files not matching the regexp provided will not be created.
+Directories are not filtered.
+
+```go
+fs := afero.NewRegexpFs(afero.NewMemMapFs(), regexp.MustCompile(`\.txt$`))
+_, err := fs.Create("/file.html")
+// err = syscall.ENOENT
+```
+
+### HttpFs
+
+Afero provides an http compatible backend which can wrap any of the existing
+backends.
+
+The Http package requires a slightly specific version of Open which
+returns an http.File type.
+
+Afero provides an httpFs file system which satisfies this requirement.
+Any Afero FileSystem can be used as an httpFs.
+
+```go
+httpFs := afero.NewHttpFs(<ExistingFS>)
+fileserver := http.FileServer(httpFs.Dir(<PATH>))
+http.Handle("/", fileserver)
+```
+
+## Composite Backends
+
+Afero provides the ability have two filesystems (or more) act as a single
+file system.
+
+### CacheOnReadFs
+
+The CacheOnReadFs will lazily make copies of any accessed files from the base
+layer into the overlay. Subsequent reads will be pulled from the overlay
+directly permitting the request is within the cache duration of when it was
+created in the overlay.
+
+If the base filesystem is writeable, any changes to files will be
+done first to the base, then to the overlay layer. Write calls to open file
+handles like `Write()` or `Truncate()` to the overlay first.
+
+To writing files to the overlay only, you can use the overlay Fs directly (not
+via the union Fs).
+
+Cache files in the layer for the given time.Duration, a cache duration of 0
+means "forever" meaning the file will not be re-requested from the base ever.
+
+A read-only base will make the overlay also read-only but still copy files
+from the base to the overlay when they're not present (or outdated) in the
+caching layer.
+
+```go
+base := afero.NewOsFs()
+layer := afero.NewMemMapFs()
+ufs := afero.NewCacheOnReadFs(base, layer, 100 * time.Second)
+```
+
+### CopyOnWriteFs()
+
+The CopyOnWriteFs is a read only base file system with a potentially
+writeable layer on top.
+
+Read operations will first look in the overlay and if not found there, will
+serve the file from the base.
+
+Changes to the file system will only be made in the overlay.
+
+Any attempt to modify a file found only in the base will copy the file to the
+overlay layer before modification (including opening a file with a writable
+handle).
+
+Removing and Renaming files present only in the base layer is not currently
+permitted. If a file is present in the base layer and the overlay, only the
+overlay will be removed/renamed.
+
+```go
+	base := afero.NewOsFs()
+	roBase := afero.NewReadOnlyFs(base)
+	ufs := afero.NewCopyOnWriteFs(roBase, afero.NewMemMapFs())
+
+	fh, _ = ufs.Create("/home/test/file2.txt")
+	fh.WriteString("This is a test")
+	fh.Close()
+```
+
+In this example all write operations will only occur in memory (MemMapFs)
+leaving the base filesystem (OsFs) untouched.
+
+
+## Desired/possible backends
+
+The following is a short list of possible backends we hope someone will
+implement:
+
+* SSH
+* S3
+
+# About the project
+
+## What's in the name
+
+Afero comes from the latin roots Ad-Facere.
+
+**"Ad"** is a prefix meaning "to".
+
+**"Facere"** is a form of the root "faciō" making "make or do".
+
+The literal meaning of afero is "to make" or "to do" which seems very fitting
+for a library that allows one to make files and directories and do things with them.
+
+The English word that shares the same roots as Afero is "affair". Affair shares
+the same concept but as a noun it means "something that is made or done" or "an
+object of a particular type".
+
+It's also nice that unlike some of my other libraries (hugo, cobra, viper) it
+Googles very well.
+
+## Release Notes
+
+See the [Releases Page](https://github.com/spf13/afero/releases).
+
+## Contributing
+
+1. Fork it
+2. Create your feature branch (`git checkout -b my-new-feature`)
+3. Commit your changes (`git commit -am 'Add some feature'`)
+4. Push to the branch (`git push origin my-new-feature`)
+5. Create new Pull Request
+
+## Contributors
+
+Names in no particular order:
+
+* [spf13](https://github.com/spf13)
+* [jaqx0r](https://github.com/jaqx0r)
+* [mbertschler](https://github.com/mbertschler)
+* [xor-gate](https://github.com/xor-gate)
+
+## License
+
+Afero is released under the Apache 2.0 license. See
+[LICENSE.txt](https://github.com/spf13/afero/blob/master/LICENSE.txt)

vendor/github.com/spf13/afero/afero.go

@@ -0,0 +1,111 @@
+// Copyright © 2014 Steve Francia <spf@spf13.com>.
+// Copyright 2013 tsuru authors. All rights reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// Package afero provides types and methods for interacting with the filesystem,
+// as an abstraction layer.
+
+// Afero also provides a few implementations that are mostly interoperable. One that
+// uses the operating system filesystem, one that uses memory to store files
+// (cross platform) and an interface that should be implemented if you want to
+// provide your own filesystem.
+
+package afero
+
+import (
+	"errors"
+	"io"
+	"os"
+	"time"
+)
+
+type Afero struct {
+	Fs
+}
+
+// File represents a file in the filesystem.
+type File interface {
+	io.Closer
+	io.Reader
+	io.ReaderAt
+	io.Seeker
+	io.Writer
+	io.WriterAt
+
+	Name() string
+	Readdir(count int) ([]os.FileInfo, error)
+	Readdirnames(n int) ([]string, error)
+	Stat() (os.FileInfo, error)
+	Sync() error
+	Truncate(size int64) error
+	WriteString(s string) (ret int, err error)
+}
+
+// Fs is the filesystem interface.
+//
+// Any simulated or real filesystem should implement this interface.
+type Fs interface {
+	// Create creates a file in the filesystem, returning the file and an
+	// error, if any happens.
+	Create(name string) (File, error)
+
+	// Mkdir creates a directory in the filesystem, return an error if any
+	// happens.
+	Mkdir(name string, perm os.FileMode) error
+
+	// MkdirAll creates a directory path and all parents that does not exist
+	// yet.
+	MkdirAll(path string, perm os.FileMode) error
+
+	// Open opens a file, returning it or an error, if any happens.
+	Open(name string) (File, error)
+
+	// OpenFile opens a file using the given flags and the given mode.
+	OpenFile(name string, flag int, perm os.FileMode) (File, error)
+
+	// Remove removes a file identified by name, returning an error, if any
+	// happens.
+	Remove(name string) error
+
+	// RemoveAll removes a directory path and any children it contains. It
+	// does not fail if the path does not exist (return nil).
+	RemoveAll(path string) error
+
+	// Rename renames a file.
+	Rename(oldname, newname string) error
+
+	// Stat returns a FileInfo describing the named file, or an error, if any
+	// happens.
+	Stat(name string) (os.FileInfo, error)
+
+	// The name of this FileSystem
+	Name() string
+
+	// Chmod changes the mode of the named file to mode.
+	Chmod(name string, mode os.FileMode) error
+
+	// Chown changes the uid and gid of the named file.
+	Chown(name string, uid, gid int) error
+
+	// Chtimes changes the access and modification times of the named file
+	Chtimes(name string, atime time.Time, mtime time.Time) error
+}
+
+var (
+	ErrFileClosed        = errors.New("File is closed")
+	ErrOutOfRange        = errors.New("out of range")
+	ErrTooLarge          = errors.New("too large")
+	ErrFileNotFound      = os.ErrNotExist
+	ErrFileExists        = os.ErrExist
+	ErrDestinationExists = os.ErrExist
+)

vendor/github.com/spf13/afero/appveyor.yml

@@ -0,0 +1,10 @@
+# This currently does nothing. We have moved to GitHub action, but this is kept
+# until spf13 has disabled this project in AppVeyor.
+version: '{build}'
+clone_folder: C:\gopath\src\github.com\spf13\afero
+environment:
+  GOPATH: C:\gopath
+build_script:
+- cmd: >-
+    go version
+

vendor/github.com/spf13/afero/basepath.go

@@ -0,0 +1,222 @@
+package afero
+
+import (
+	"io/fs"
+	"os"
+	"path/filepath"
+	"runtime"
+	"strings"
+	"time"
+)
+
+var (
+	_ Lstater        = (*BasePathFs)(nil)
+	_ fs.ReadDirFile = (*BasePathFile)(nil)
+)
+
+// The BasePathFs restricts all operations to a given path within an Fs.
+// The given file name to the operations on this Fs will be prepended with
+// the base path before calling the base Fs.
+// Any file name (after filepath.Clean()) outside this base path will be
+// treated as non existing file.
+//
+// Note that it does not clean the error messages on return, so you may
+// reveal the real path on errors.
+type BasePathFs struct {
+	source Fs
+	path   string
+}
+
+type BasePathFile struct {
+	File
+	path string
+}
+
+func (f *BasePathFile) Name() string {
+	sourcename := f.File.Name()
+	return strings.TrimPrefix(sourcename, filepath.Clean(f.path))
+}
+
+func (f *BasePathFile) ReadDir(n int) ([]fs.DirEntry, error) {
+	if rdf, ok := f.File.(fs.ReadDirFile); ok {
+		return rdf.ReadDir(n)
+	}
+	return readDirFile{f.File}.ReadDir(n)
+}
+
+func NewBasePathFs(source Fs, path string) Fs {
+	return &BasePathFs{source: source, path: path}
+}
+
+// on a file outside the base path it returns the given file name and an error,
+// else the given file with the base path prepended
+func (b *BasePathFs) RealPath(name string) (path string, err error) {
+	if err := validateBasePathName(name); err != nil {
+		return name, err
+	}
+
+	bpath := filepath.Clean(b.path)
+	path = filepath.Clean(filepath.Join(bpath, name))
+	if !strings.HasPrefix(path, bpath) {
+		return name, os.ErrNotExist
+	}
+
+	return path, nil
+}
+
+func validateBasePathName(name string) error {
+	if runtime.GOOS != "windows" {
+		// Not much to do here;
+		// the virtual file paths all look absolute on *nix.
+		return nil
+	}
+
+	// On Windows a common mistake would be to provide an absolute OS path
+	// We could strip out the base part, but that would not be very portable.
+	if filepath.IsAbs(name) {
+		return os.ErrNotExist
+	}
+
+	return nil
+}
+
+func (b *BasePathFs) Chtimes(name string, atime, mtime time.Time) (err error) {
+	if name, err = b.RealPath(name); err != nil {
+		return &os.PathError{Op: "chtimes", Path: name, Err: err}
+	}
+	return b.source.Chtimes(name, atime, mtime)
+}
+
+func (b *BasePathFs) Chmod(name string, mode os.FileMode) (err error) {
+	if name, err = b.RealPath(name); err != nil {
+		return &os.PathError{Op: "chmod", Path: name, Err: err}
+	}
+	return b.source.Chmod(name, mode)
+}
+
+func (b *BasePathFs) Chown(name string, uid, gid int) (err error) {
+	if name, err = b.RealPath(name); err != nil {
+		return &os.PathError{Op: "chown", Path: name, Err: err}
+	}
+	return b.source.Chown(name, uid, gid)
+}
+
+func (b *BasePathFs) Name() string {
+	return "BasePathFs"
+}
+
+func (b *BasePathFs) Stat(name string) (fi os.FileInfo, err error) {
+	if name, err = b.RealPath(name); err != nil {
+		return nil, &os.PathError{Op: "stat", Path: name, Err: err}
+	}
+	return b.source.Stat(name)
+}
+
+func (b *BasePathFs) Rename(oldname, newname string) (err error) {
+	if oldname, err = b.RealPath(oldname); err != nil {
+		return &os.PathError{Op: "rename", Path: oldname, Err: err}
+	}
+	if newname, err = b.RealPath(newname); err != nil {
+		return &os.PathError{Op: "rename", Path: newname, Err: err}
+	}
+	return b.source.Rename(oldname, newname)
+}
+
+func (b *BasePathFs) RemoveAll(name string) (err error) {
+	if name, err = b.RealPath(name); err != nil {
+		return &os.PathError{Op: "remove_all", Path: name, Err: err}
+	}
+	return b.source.RemoveAll(name)
+}
+
+func (b *BasePathFs) Remove(name string) (err error) {
+	if name, err = b.RealPath(name); err != nil {
+		return &os.PathError{Op: "remove", Path: name, Err: err}
+	}
+	return b.source.Remove(name)
+}
+
+func (b *BasePathFs) OpenFile(name string, flag int, mode os.FileMode) (f File, err error) {
+	if name, err = b.RealPath(name); err != nil {
+		return nil, &os.PathError{Op: "openfile", Path: name, Err: err}
+	}
+	sourcef, err := b.source.OpenFile(name, flag, mode)
+	if err != nil {
+		return nil, err
+	}
+	return &BasePathFile{sourcef, b.path}, nil
+}
+
+func (b *BasePathFs) Open(name string) (f File, err error) {
+	if name, err = b.RealPath(name); err != nil {
+		return nil, &os.PathError{Op: "open", Path: name, Err: err}
+	}
+	sourcef, err := b.source.Open(name)
+	if err != nil {
+		return nil, err
+	}
+	return &BasePathFile{File: sourcef, path: b.path}, nil
+}
+
+func (b *BasePathFs) Mkdir(name string, mode os.FileMode) (err error) {
+	if name, err = b.RealPath(name); err != nil {
+		return &os.PathError{Op: "mkdir", Path: name, Err: err}
+	}
+	return b.source.Mkdir(name, mode)
+}
+
+func (b *BasePathFs) MkdirAll(name string, mode os.FileMode) (err error) {
+	if name, err = b.RealPath(name); err != nil {
+		return &os.PathError{Op: "mkdir", Path: name, Err: err}
+	}
+	return b.source.MkdirAll(name, mode)
+}
+
+func (b *BasePathFs) Create(name string) (f File, err error) {
+	if name, err = b.RealPath(name); err != nil {
+		return nil, &os.PathError{Op: "create", Path: name, Err: err}
+	}
+	sourcef, err := b.source.Create(name)
+	if err != nil {
+		return nil, err
+	}
+	return &BasePathFile{File: sourcef, path: b.path}, nil
+}
+
+func (b *BasePathFs) LstatIfPossible(name string) (os.FileInfo, bool, error) {
+	name, err := b.RealPath(name)
+	if err != nil {
+		return nil, false, &os.PathError{Op: "lstat", Path: name, Err: err}
+	}
+	if lstater, ok := b.source.(Lstater); ok {
+		return lstater.LstatIfPossible(name)
+	}
+	fi, err := b.source.Stat(name)
+	return fi, false, err
+}
+
+func (b *BasePathFs) SymlinkIfPossible(oldname, newname string) error {
+	oldname, err := b.RealPath(oldname)
+	if err != nil {
+		return &os.LinkError{Op: "symlink", Old: oldname, New: newname, Err: err}
+	}
+	newname, err = b.RealPath(newname)
+	if err != nil {
+		return &os.LinkError{Op: "symlink", Old: oldname, New: newname, Err: err}
+	}
+	if linker, ok := b.source.(Linker); ok {
+		return linker.SymlinkIfPossible(oldname, newname)
+	}
+	return &os.LinkError{Op: "symlink", Old: oldname, New: newname, Err: ErrNoSymlink}
+}
+
+func (b *BasePathFs) ReadlinkIfPossible(name string) (string, error) {
+	name, err := b.RealPath(name)
+	if err != nil {
+		return "", &os.PathError{Op: "readlink", Path: name, Err: err}
+	}
+	if reader, ok := b.source.(LinkReader); ok {
+		return reader.ReadlinkIfPossible(name)
+	}
+	return "", &os.PathError{Op: "readlink", Path: name, Err: ErrNoReadlink}
+}

vendor/github.com/spf13/afero/cacheOnReadFs.go

@@ -0,0 +1,315 @@
+package afero
+
+import (
+	"os"
+	"syscall"
+	"time"
+)
+
+// If the cache duration is 0, cache time will be unlimited, i.e. once
+// a file is in the layer, the base will never be read again for this file.
+//
+// For cache times greater than 0, the modification time of a file is
+// checked. Note that a lot of file system implementations only allow a
+// resolution of a second for timestamps... or as the godoc for os.Chtimes()
+// states: "The underlying filesystem may truncate or round the values to a
+// less precise time unit."
+//
+// This caching union will forward all write calls also to the base file
+// system first. To prevent writing to the base Fs, wrap it in a read-only
+// filter - Note: this will also make the overlay read-only, for writing files
+// in the overlay, use the overlay Fs directly, not via the union Fs.
+type CacheOnReadFs struct {
+	base      Fs
+	layer     Fs
+	cacheTime time.Duration
+}
+
+func NewCacheOnReadFs(base Fs, layer Fs, cacheTime time.Duration) Fs {
+	return &CacheOnReadFs{base: base, layer: layer, cacheTime: cacheTime}
+}
+
+type cacheState int
+
+const (
+	// not present in the overlay, unknown if it exists in the base:
+	cacheMiss cacheState = iota
+	// present in the overlay and in base, base file is newer:
+	cacheStale
+	// present in the overlay - with cache time == 0 it may exist in the base,
+	// with cacheTime > 0 it exists in the base and is same age or newer in the
+	// overlay
+	cacheHit
+	// happens if someone writes directly to the overlay without
+	// going through this union
+	cacheLocal
+)
+
+func (u *CacheOnReadFs) cacheStatus(name string) (state cacheState, fi os.FileInfo, err error) {
+	var lfi, bfi os.FileInfo
+	lfi, err = u.layer.Stat(name)
+	if err == nil {
+		if u.cacheTime == 0 {
+			return cacheHit, lfi, nil
+		}
+		if lfi.ModTime().Add(u.cacheTime).Before(time.Now()) {
+			bfi, err = u.base.Stat(name)
+			if err != nil {
+				return cacheLocal, lfi, nil
+			}
+			if bfi.ModTime().After(lfi.ModTime()) {
+				return cacheStale, bfi, nil
+			}
+		}
+		return cacheHit, lfi, nil
+	}
+
+	if err == syscall.ENOENT || os.IsNotExist(err) {
+		return cacheMiss, nil, nil
+	}
+
+	return cacheMiss, nil, err
+}
+
+func (u *CacheOnReadFs) copyToLayer(name string) error {
+	return copyToLayer(u.base, u.layer, name)
+}
+
+func (u *CacheOnReadFs) copyFileToLayer(name string, flag int, perm os.FileMode) error {
+	return copyFileToLayer(u.base, u.layer, name, flag, perm)
+}
+
+func (u *CacheOnReadFs) Chtimes(name string, atime, mtime time.Time) error {
+	st, _, err := u.cacheStatus(name)
+	if err != nil {
+		return err
+	}
+	switch st {
+	case cacheLocal:
+	case cacheHit:
+		err = u.base.Chtimes(name, atime, mtime)
+	case cacheStale, cacheMiss:
+		if err := u.copyToLayer(name); err != nil {
+			return err
+		}
+		err = u.base.Chtimes(name, atime, mtime)
+	}
+	if err != nil {
+		return err
+	}
+	return u.layer.Chtimes(name, atime, mtime)
+}
+
+func (u *CacheOnReadFs) Chmod(name string, mode os.FileMode) error {
+	st, _, err := u.cacheStatus(name)
+	if err != nil {
+		return err
+	}
+	switch st {
+	case cacheLocal:
+	case cacheHit:
+		err = u.base.Chmod(name, mode)
+	case cacheStale, cacheMiss:
+		if err := u.copyToLayer(name); err != nil {
+			return err
+		}
+		err = u.base.Chmod(name, mode)
+	}
+	if err != nil {
+		return err
+	}
+	return u.layer.Chmod(name, mode)
+}
+
+func (u *CacheOnReadFs) Chown(name string, uid, gid int) error {
+	st, _, err := u.cacheStatus(name)
+	if err != nil {
+		return err
+	}
+	switch st {
+	case cacheLocal:
+	case cacheHit:
+		err = u.base.Chown(name, uid, gid)
+	case cacheStale, cacheMiss:
+		if err := u.copyToLayer(name); err != nil {
+			return err
+		}
+		err = u.base.Chown(name, uid, gid)
+	}
+	if err != nil {
+		return err
+	}
+	return u.layer.Chown(name, uid, gid)
+}
+
+func (u *CacheOnReadFs) Stat(name string) (os.FileInfo, error) {
+	st, fi, err := u.cacheStatus(name)
+	if err != nil {
+		return nil, err
+	}
+	switch st {
+	case cacheMiss:
+		return u.base.Stat(name)
+	default: // cacheStale has base, cacheHit and cacheLocal the layer os.FileInfo
+		return fi, nil
+	}
+}
+
+func (u *CacheOnReadFs) Rename(oldname, newname string) error {
+	st, _, err := u.cacheStatus(oldname)
+	if err != nil {
+		return err
+	}
+	switch st {
+	case cacheLocal:
+	case cacheHit:
+		err = u.base.Rename(oldname, newname)
+	case cacheStale, cacheMiss:
+		if err := u.copyToLayer(oldname); err != nil {
+			return err
+		}
+		err = u.base.Rename(oldname, newname)
+	}
+	if err != nil {
+		return err
+	}
+	return u.layer.Rename(oldname, newname)
+}
+
+func (u *CacheOnReadFs) Remove(name string) error {
+	st, _, err := u.cacheStatus(name)
+	if err != nil {
+		return err
+	}
+	switch st {
+	case cacheLocal:
+	case cacheHit, cacheStale, cacheMiss:
+		err = u.base.Remove(name)
+	}
+	if err != nil {
+		return err
+	}
+	return u.layer.Remove(name)
+}
+
+func (u *CacheOnReadFs) RemoveAll(name string) error {
+	st, _, err := u.cacheStatus(name)
+	if err != nil {
+		return err
+	}
+	switch st {
+	case cacheLocal:
+	case cacheHit, cacheStale, cacheMiss:
+		err = u.base.RemoveAll(name)
+	}
+	if err != nil {
+		return err
+	}
+	return u.layer.RemoveAll(name)
+}
+
+func (u *CacheOnReadFs) OpenFile(name string, flag int, perm os.FileMode) (File, error) {
+	st, _, err := u.cacheStatus(name)
+	if err != nil {
+		return nil, err
+	}
+	switch st {
+	case cacheLocal, cacheHit:
+	default:
+		if err := u.copyFileToLayer(name, flag, perm); err != nil {
+			return nil, err
+		}
+	}
+	if flag&(os.O_WRONLY|syscall.O_RDWR|os.O_APPEND|os.O_CREATE|os.O_TRUNC) != 0 {
+		bfi, err := u.base.OpenFile(name, flag, perm)
+		if err != nil {
+			return nil, err
+		}
+		lfi, err := u.layer.OpenFile(name, flag, perm)
+		if err != nil {
+			bfi.Close() // oops, what if O_TRUNC was set and file opening in the layer failed...?
+			return nil, err
+		}
+		return &UnionFile{Base: bfi, Layer: lfi}, nil
+	}
+	return u.layer.OpenFile(name, flag, perm)
+}
+
+func (u *CacheOnReadFs) Open(name string) (File, error) {
+	st, fi, err := u.cacheStatus(name)
+	if err != nil {
+		return nil, err
+	}
+
+	switch st {
+	case cacheLocal:
+		return u.layer.Open(name)
+
+	case cacheMiss:
+		bfi, err := u.base.Stat(name)
+		if err != nil {
+			return nil, err
+		}
+		if bfi.IsDir() {
+			return u.base.Open(name)
+		}
+		if err := u.copyToLayer(name); err != nil {
+			return nil, err
+		}
+		return u.layer.Open(name)
+
+	case cacheStale:
+		if !fi.IsDir() {
+			if err := u.copyToLayer(name); err != nil {
+				return nil, err
+			}
+			return u.layer.Open(name)
+		}
+	case cacheHit:
+		if !fi.IsDir() {
+			return u.layer.Open(name)
+		}
+	}
+	// the dirs from cacheHit, cacheStale fall down here:
+	bfile, _ := u.base.Open(name)
+	lfile, err := u.layer.Open(name)
+	if err != nil && bfile == nil {
+		return nil, err
+	}
+	return &UnionFile{Base: bfile, Layer: lfile}, nil
+}
+
+func (u *CacheOnReadFs) Mkdir(name string, perm os.FileMode) error {
+	err := u.base.Mkdir(name, perm)
+	if err != nil {
+		return err
+	}
+	return u.layer.MkdirAll(name, perm) // yes, MkdirAll... we cannot assume it exists in the cache
+}
+
+func (u *CacheOnReadFs) Name() string {
+	return "CacheOnReadFs"
+}
+
+func (u *CacheOnReadFs) MkdirAll(name string, perm os.FileMode) error {
+	err := u.base.MkdirAll(name, perm)
+	if err != nil {
+		return err
+	}
+	return u.layer.MkdirAll(name, perm)
+}
+
+func (u *CacheOnReadFs) Create(name string) (File, error) {
+	bfh, err := u.base.Create(name)
+	if err != nil {
+		return nil, err
+	}
+	lfh, err := u.layer.Create(name)
+	if err != nil {
+		// oops, see comment about OS_TRUNC above, should we remove? then we have to
+		// remember if the file did not exist before
+		bfh.Close()
+		return nil, err
+	}
+	return &UnionFile{Base: bfh, Layer: lfh}, nil
+}

vendor/github.com/spf13/afero/const_bsds.go

@@ -0,0 +1,23 @@
+// Copyright © 2016 Steve Francia <spf@spf13.com>.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+//go:build aix || darwin || openbsd || freebsd || netbsd || dragonfly || zos
+// +build aix darwin openbsd freebsd netbsd dragonfly zos
+
+package afero
+
+import (
+	"syscall"
+)
+
+const BADFD = syscall.EBADF

vendor/github.com/spf13/afero/const_win_unix.go

@@ -0,0 +1,22 @@
+// Copyright © 2016 Steve Francia <spf@spf13.com>.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//go:build !darwin && !openbsd && !freebsd && !dragonfly && !netbsd && !aix && !zos
+// +build !darwin,!openbsd,!freebsd,!dragonfly,!netbsd,!aix,!zos
+
+package afero
+
+import (
+	"syscall"
+)
+
+const BADFD = syscall.EBADFD

vendor/github.com/spf13/afero/copyOnWriteFs.go

@@ -0,0 +1,327 @@
+package afero
+
+import (
+	"fmt"
+	"os"
+	"path/filepath"
+	"syscall"
+	"time"
+)
+
+var _ Lstater = (*CopyOnWriteFs)(nil)
+
+// The CopyOnWriteFs is a union filesystem: a read only base file system with
+// a possibly writeable layer on top. Changes to the file system will only
+// be made in the overlay: Changing an existing file in the base layer which
+// is not present in the overlay will copy the file to the overlay ("changing"
+// includes also calls to e.g. Chtimes(), Chmod() and Chown()).
+//
+// Reading directories is currently only supported via Open(), not OpenFile().
+type CopyOnWriteFs struct {
+	base  Fs
+	layer Fs
+}
+
+func NewCopyOnWriteFs(base Fs, layer Fs) Fs {
+	return &CopyOnWriteFs{base: base, layer: layer}
+}
+
+// Returns true if the file is not in the overlay
+func (u *CopyOnWriteFs) isBaseFile(name string) (bool, error) {
+	if _, err := u.layer.Stat(name); err == nil {
+		return false, nil
+	}
+	_, err := u.base.Stat(name)
+	if err != nil {
+		if oerr, ok := err.(*os.PathError); ok {
+			if oerr.Err == os.ErrNotExist || oerr.Err == syscall.ENOENT || oerr.Err == syscall.ENOTDIR {
+				return false, nil
+			}
+		}
+		if err == syscall.ENOENT {
+			return false, nil
+		}
+	}
+	return true, err
+}
+
+func (u *CopyOnWriteFs) copyToLayer(name string) error {
+	return copyToLayer(u.base, u.layer, name)
+}
+
+func (u *CopyOnWriteFs) Chtimes(name string, atime, mtime time.Time) error {
+	b, err := u.isBaseFile(name)
+	if err != nil {
+		return err
+	}
+	if b {
+		if err := u.copyToLayer(name); err != nil {
+			return err
+		}
+	}
+	return u.layer.Chtimes(name, atime, mtime)
+}
+
+func (u *CopyOnWriteFs) Chmod(name string, mode os.FileMode) error {
+	b, err := u.isBaseFile(name)
+	if err != nil {
+		return err
+	}
+	if b {
+		if err := u.copyToLayer(name); err != nil {
+			return err
+		}
+	}
+	return u.layer.Chmod(name, mode)
+}
+
+func (u *CopyOnWriteFs) Chown(name string, uid, gid int) error {
+	b, err := u.isBaseFile(name)
+	if err != nil {
+		return err
+	}
+	if b {
+		if err := u.copyToLayer(name); err != nil {
+			return err
+		}
+	}
+	return u.layer.Chown(name, uid, gid)
+}
+
+func (u *CopyOnWriteFs) Stat(name string) (os.FileInfo, error) {
+	fi, err := u.layer.Stat(name)
+	if err != nil {
+		isNotExist := u.isNotExist(err)
+		if isNotExist {
+			return u.base.Stat(name)
+		}
+		return nil, err
+	}
+	return fi, nil
+}
+
+func (u *CopyOnWriteFs) LstatIfPossible(name string) (os.FileInfo, bool, error) {
+	llayer, ok1 := u.layer.(Lstater)
+	lbase, ok2 := u.base.(Lstater)
+
+	if ok1 {
+		fi, b, err := llayer.LstatIfPossible(name)
+		if err == nil {
+			return fi, b, nil
+		}
+
+		if !u.isNotExist(err) {
+			return nil, b, err
+		}
+	}
+
+	if ok2 {
+		fi, b, err := lbase.LstatIfPossible(name)
+		if err == nil {
+			return fi, b, nil
+		}
+		if !u.isNotExist(err) {
+			return nil, b, err
+		}
+	}
+
+	fi, err := u.Stat(name)
+
+	return fi, false, err
+}
+
+func (u *CopyOnWriteFs) SymlinkIfPossible(oldname, newname string) error {
+	if slayer, ok := u.layer.(Linker); ok {
+		return slayer.SymlinkIfPossible(oldname, newname)
+	}
+
+	return &os.LinkError{Op: "symlink", Old: oldname, New: newname, Err: ErrNoSymlink}
+}
+
+func (u *CopyOnWriteFs) ReadlinkIfPossible(name string) (string, error) {
+	if rlayer, ok := u.layer.(LinkReader); ok {
+		return rlayer.ReadlinkIfPossible(name)
+	}
+
+	if rbase, ok := u.base.(LinkReader); ok {
+		return rbase.ReadlinkIfPossible(name)
+	}
+
+	return "", &os.PathError{Op: "readlink", Path: name, Err: ErrNoReadlink}
+}
+
+func (u *CopyOnWriteFs) isNotExist(err error) bool {
+	if e, ok := err.(*os.PathError); ok {
+		err = e.Err
+	}
+	if err == os.ErrNotExist || err == syscall.ENOENT || err == syscall.ENOTDIR {
+		return true
+	}
+	return false
+}
+
+// Renaming files present only in the base layer is not permitted
+func (u *CopyOnWriteFs) Rename(oldname, newname string) error {
+	b, err := u.isBaseFile(oldname)
+	if err != nil {
+		return err
+	}
+	if b {
+		return syscall.EPERM
+	}
+	return u.layer.Rename(oldname, newname)
+}
+
+// Removing files present only in the base layer is not permitted. If
+// a file is present in the base layer and the overlay, only the overlay
+// will be removed.
+func (u *CopyOnWriteFs) Remove(name string) error {
+	err := u.layer.Remove(name)
+	switch err {
+	case syscall.ENOENT:
+		_, err = u.base.Stat(name)
+		if err == nil {
+			return syscall.EPERM
+		}
+		return syscall.ENOENT
+	default:
+		return err
+	}
+}
+
+func (u *CopyOnWriteFs) RemoveAll(name string) error {
+	err := u.layer.RemoveAll(name)
+	switch err {
+	case syscall.ENOENT:
+		_, err = u.base.Stat(name)
+		if err == nil {
+			return syscall.EPERM
+		}
+		return syscall.ENOENT
+	default:
+		return err
+	}
+}
+
+func (u *CopyOnWriteFs) OpenFile(name string, flag int, perm os.FileMode) (File, error) {
+	b, err := u.isBaseFile(name)
+	if err != nil {
+		return nil, err
+	}
+
+	if flag&(os.O_WRONLY|os.O_RDWR|os.O_APPEND|os.O_CREATE|os.O_TRUNC) != 0 {
+		if b {
+			if err = u.copyToLayer(name); err != nil {
+				return nil, err
+			}
+			return u.layer.OpenFile(name, flag, perm)
+		}
+
+		dir := filepath.Dir(name)
+		isaDir, err := IsDir(u.base, dir)
+		if err != nil && !os.IsNotExist(err) {
+			return nil, err
+		}
+		if isaDir {
+			if err = u.layer.MkdirAll(dir, 0o777); err != nil {
+				return nil, err
+			}
+			return u.layer.OpenFile(name, flag, perm)
+		}
+
+		isaDir, err = IsDir(u.layer, dir)
+		if err != nil {
+			return nil, err
+		}
+		if isaDir {
+			return u.layer.OpenFile(name, flag, perm)
+		}
+
+		return nil, &os.PathError{Op: "open", Path: name, Err: syscall.ENOTDIR} // ...or os.ErrNotExist?
+	}
+	if b {
+		return u.base.OpenFile(name, flag, perm)
+	}
+	return u.layer.OpenFile(name, flag, perm)
+}
+
+// This function handles the 9 different possibilities caused
+// by the union which are the intersection of the following...
+//
+//	layer: doesn't exist, exists as a file, and exists as a directory
+//	base:  doesn't exist, exists as a file, and exists as a directory
+func (u *CopyOnWriteFs) Open(name string) (File, error) {
+	// Since the overlay overrides the base we check that first
+	b, err := u.isBaseFile(name)
+	if err != nil {
+		return nil, err
+	}
+
+	// If overlay doesn't exist, return the base (base state irrelevant)
+	if b {
+		return u.base.Open(name)
+	}
+
+	// If overlay is a file, return it (base state irrelevant)
+	dir, err := IsDir(u.layer, name)
+	if err != nil {
+		return nil, err
+	}
+	if !dir {
+		return u.layer.Open(name)
+	}
+
+	// Overlay is a directory, base state now matters.
+	// Base state has 3 states to check but 2 outcomes:
+	// A. It's a file or non-readable in the base (return just the overlay)
+	// B. It's an accessible directory in the base (return a UnionFile)
+
+	// If base is file or nonreadable, return overlay
+	dir, err = IsDir(u.base, name)
+	if !dir || err != nil {
+		return u.layer.Open(name)
+	}
+
+	// Both base & layer are directories
+	// Return union file (if opens are without error)
+	bfile, bErr := u.base.Open(name)
+	lfile, lErr := u.layer.Open(name)
+
+	// If either have errors at this point something is very wrong. Return nil and the errors
+	if bErr != nil || lErr != nil {
+		return nil, fmt.Errorf("BaseErr: %v\nOverlayErr: %v", bErr, lErr)
+	}
+
+	return &UnionFile{Base: bfile, Layer: lfile}, nil
+}
+
+func (u *CopyOnWriteFs) Mkdir(name string, perm os.FileMode) error {
+	dir, err := IsDir(u.base, name)
+	if err != nil {
+		return u.layer.MkdirAll(name, perm)
+	}
+	if dir {
+		return ErrFileExists
+	}
+	return u.layer.MkdirAll(name, perm)
+}
+
+func (u *CopyOnWriteFs) Name() string {
+	return "CopyOnWriteFs"
+}
+
+func (u *CopyOnWriteFs) MkdirAll(name string, perm os.FileMode) error {
+	dir, err := IsDir(u.base, name)
+	if err != nil {
+		return u.layer.MkdirAll(name, perm)
+	}
+	if dir {
+		// This is in line with how os.MkdirAll behaves.
+		return nil
+	}
+	return u.layer.MkdirAll(name, perm)
+}
+
+func (u *CopyOnWriteFs) Create(name string) (File, error) {
+	return u.OpenFile(name, os.O_CREATE|os.O_TRUNC|os.O_RDWR, 0o666)
+}

vendor/github.com/spf13/afero/httpFs.go

@@ -0,0 +1,114 @@
+// Copyright © 2014 Steve Francia <spf@spf13.com>.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package afero
+
+import (
+	"errors"
+	"net/http"
+	"os"
+	"path"
+	"path/filepath"
+	"strings"
+	"time"
+)
+
+type httpDir struct {
+	basePath string
+	fs       HttpFs
+}
+
+func (d httpDir) Open(name string) (http.File, error) {
+	if filepath.Separator != '/' && strings.ContainsRune(name, filepath.Separator) ||
+		strings.Contains(name, "\x00") {
+		return nil, errors.New("http: invalid character in file path")
+	}
+	dir := string(d.basePath)
+	if dir == "" {
+		dir = "."
+	}
+
+	f, err := d.fs.Open(filepath.Join(dir, filepath.FromSlash(path.Clean("/"+name))))
+	if err != nil {
+		return nil, err
+	}
+	return f, nil
+}
+
+type HttpFs struct {
+	source Fs
+}
+
+func NewHttpFs(source Fs) *HttpFs {
+	return &HttpFs{source: source}
+}
+
+func (h HttpFs) Dir(s string) *httpDir {
+	return &httpDir{basePath: s, fs: h}
+}
+
+func (h HttpFs) Name() string { return "h HttpFs" }
+
+func (h HttpFs) Create(name string) (File, error) {
+	return h.source.Create(name)
+}
+
+func (h HttpFs) Chmod(name string, mode os.FileMode) error {
+	return h.source.Chmod(name, mode)
+}
+
+func (h HttpFs) Chown(name string, uid, gid int) error {
+	return h.source.Chown(name, uid, gid)
+}
+
+func (h HttpFs) Chtimes(name string, atime time.Time, mtime time.Time) error {
+	return h.source.Chtimes(name, atime, mtime)
+}
+
+func (h HttpFs) Mkdir(name string, perm os.FileMode) error {
+	return h.source.Mkdir(name, perm)
+}
+
+func (h HttpFs) MkdirAll(path string, perm os.FileMode) error {
+	return h.source.MkdirAll(path, perm)
+}
+
+func (h HttpFs) Open(name string) (http.File, error) {
+	f, err := h.source.Open(name)
+	if err == nil {
+		if httpfile, ok := f.(http.File); ok {
+			return httpfile, nil
+		}
+	}
+	return nil, err
+}
+
+func (h HttpFs) OpenFile(name string, flag int, perm os.FileMode) (File, error) {
+	return h.source.OpenFile(name, flag, perm)
+}
+
+func (h HttpFs) Remove(name string) error {
+	return h.source.Remove(name)
+}
+
+func (h HttpFs) RemoveAll(path string) error {
+	return h.source.RemoveAll(path)
+}
+
+func (h HttpFs) Rename(oldname, newname string) error {
+	return h.source.Rename(oldname, newname)
+}
+
+func (h HttpFs) Stat(name string) (os.FileInfo, error) {
+	return h.source.Stat(name)
+}

vendor/github.com/spf13/afero/internal/common/adapters.go

@@ -0,0 +1,27 @@
+// Copyright © 2022 Steve Francia <spf@spf13.com>.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package common
+
+import "io/fs"
+
+// FileInfoDirEntry provides an adapter from os.FileInfo to fs.DirEntry
+type FileInfoDirEntry struct {
+	fs.FileInfo
+}
+
+var _ fs.DirEntry = FileInfoDirEntry{}
+
+func (d FileInfoDirEntry) Type() fs.FileMode { return d.FileInfo.Mode().Type() }
+
+func (d FileInfoDirEntry) Info() (fs.FileInfo, error) { return d.FileInfo, nil }

vendor/github.com/spf13/afero/iofs.go

@@ -0,0 +1,298 @@
+//go:build go1.16
+// +build go1.16
+
+package afero
+
+import (
+	"io"
+	"io/fs"
+	"os"
+	"path"
+	"sort"
+	"time"
+
+	"github.com/spf13/afero/internal/common"
+)
+
+// IOFS adopts afero.Fs to stdlib io/fs.FS
+type IOFS struct {
+	Fs
+}
+
+func NewIOFS(fs Fs) IOFS {
+	return IOFS{Fs: fs}
+}
+
+var (
+	_ fs.FS         = IOFS{}
+	_ fs.GlobFS     = IOFS{}
+	_ fs.ReadDirFS  = IOFS{}
+	_ fs.ReadFileFS = IOFS{}
+	_ fs.StatFS     = IOFS{}
+	_ fs.SubFS      = IOFS{}
+)
+
+func (iofs IOFS) Open(name string) (fs.File, error) {
+	const op = "open"
+
+	// by convention for fs.FS implementations we should perform this check
+	if !fs.ValidPath(name) {
+		return nil, iofs.wrapError(op, name, fs.ErrInvalid)
+	}
+
+	file, err := iofs.Fs.Open(name)
+	if err != nil {
+		return nil, iofs.wrapError(op, name, err)
+	}
+
+	// file should implement fs.ReadDirFile
+	if _, ok := file.(fs.ReadDirFile); !ok {
+		file = readDirFile{file}
+	}
+
+	return file, nil
+}
+
+func (iofs IOFS) Glob(pattern string) ([]string, error) {
+	const op = "glob"
+
+	// afero.Glob does not perform this check but it's required for implementations
+	if _, err := path.Match(pattern, ""); err != nil {
+		return nil, iofs.wrapError(op, pattern, err)
+	}
+
+	items, err := Glob(iofs.Fs, pattern)
+	if err != nil {
+		return nil, iofs.wrapError(op, pattern, err)
+	}
+
+	return items, nil
+}
+
+func (iofs IOFS) ReadDir(name string) ([]fs.DirEntry, error) {
+	f, err := iofs.Fs.Open(name)
+	if err != nil {
+		return nil, iofs.wrapError("readdir", name, err)
+	}
+
+	defer f.Close()
+
+	if rdf, ok := f.(fs.ReadDirFile); ok {
+		items, err := rdf.ReadDir(-1)
+		if err != nil {
+			return nil, iofs.wrapError("readdir", name, err)
+		}
+		sort.Slice(items, func(i, j int) bool { return items[i].Name() < items[j].Name() })
+		return items, nil
+	}
+
+	items, err := f.Readdir(-1)
+	if err != nil {
+		return nil, iofs.wrapError("readdir", name, err)
+	}
+	sort.Sort(byName(items))
+
+	ret := make([]fs.DirEntry, len(items))
+	for i := range items {
+		ret[i] = common.FileInfoDirEntry{FileInfo: items[i]}
+	}
+
+	return ret, nil
+}
+
+func (iofs IOFS) ReadFile(name string) ([]byte, error) {
+	const op = "readfile"
+
+	if !fs.ValidPath(name) {
+		return nil, iofs.wrapError(op, name, fs.ErrInvalid)
+	}
+
+	bytes, err := ReadFile(iofs.Fs, name)
+	if err != nil {
+		return nil, iofs.wrapError(op, name, err)
+	}
+
+	return bytes, nil
+}
+
+func (iofs IOFS) Sub(dir string) (fs.FS, error) { return IOFS{NewBasePathFs(iofs.Fs, dir)}, nil }
+
+func (IOFS) wrapError(op, path string, err error) error {
+	if _, ok := err.(*fs.PathError); ok {
+		return err // don't need to wrap again
+	}
+
+	return &fs.PathError{
+		Op:   op,
+		Path: path,
+		Err:  err,
+	}
+}
+
+// readDirFile provides adapter from afero.File to fs.ReadDirFile needed for correct Open
+type readDirFile struct {
+	File
+}
+
+var _ fs.ReadDirFile = readDirFile{}
+
+func (r readDirFile) ReadDir(n int) ([]fs.DirEntry, error) {
+	items, err := r.File.Readdir(n)
+	if err != nil {
+		return nil, err
+	}
+
+	ret := make([]fs.DirEntry, len(items))
+	for i := range items {
+		ret[i] = common.FileInfoDirEntry{FileInfo: items[i]}
+	}
+
+	return ret, nil
+}
+
+// FromIOFS adopts io/fs.FS to use it as afero.Fs
+// Note that io/fs.FS is read-only so all mutating methods will return fs.PathError with fs.ErrPermission
+// To store modifications you may use afero.CopyOnWriteFs
+type FromIOFS struct {
+	fs.FS
+}
+
+var _ Fs = FromIOFS{}
+
+func (f FromIOFS) Create(name string) (File, error) { return nil, notImplemented("create", name) }
+
+func (f FromIOFS) Mkdir(name string, perm os.FileMode) error { return notImplemented("mkdir", name) }
+
+func (f FromIOFS) MkdirAll(path string, perm os.FileMode) error {
+	return notImplemented("mkdirall", path)
+}
+
+func (f FromIOFS) Open(name string) (File, error) {
+	file, err := f.FS.Open(name)
+	if err != nil {
+		return nil, err
+	}
+
+	return fromIOFSFile{File: file, name: name}, nil
+}
+
+func (f FromIOFS) OpenFile(name string, flag int, perm os.FileMode) (File, error) {
+	return f.Open(name)
+}
+
+func (f FromIOFS) Remove(name string) error {
+	return notImplemented("remove", name)
+}
+
+func (f FromIOFS) RemoveAll(path string) error {
+	return notImplemented("removeall", path)
+}
+
+func (f FromIOFS) Rename(oldname, newname string) error {
+	return notImplemented("rename", oldname)
+}
+
+func (f FromIOFS) Stat(name string) (os.FileInfo, error) { return fs.Stat(f.FS, name) }
+
+func (f FromIOFS) Name() string { return "fromiofs" }
+
+func (f FromIOFS) Chmod(name string, mode os.FileMode) error {
+	return notImplemented("chmod", name)
+}
+
+func (f FromIOFS) Chown(name string, uid, gid int) error {
+	return notImplemented("chown", name)
+}
+
+func (f FromIOFS) Chtimes(name string, atime time.Time, mtime time.Time) error {
+	return notImplemented("chtimes", name)
+}
+
+type fromIOFSFile struct {
+	fs.File
+	name string
+}
+
+func (f fromIOFSFile) ReadAt(p []byte, off int64) (n int, err error) {
+	readerAt, ok := f.File.(io.ReaderAt)
+	if !ok {
+		return -1, notImplemented("readat", f.name)
+	}
+
+	return readerAt.ReadAt(p, off)
+}
+
+func (f fromIOFSFile) Seek(offset int64, whence int) (int64, error) {
+	seeker, ok := f.File.(io.Seeker)
+	if !ok {
+		return -1, notImplemented("seek", f.name)
+	}
+
+	return seeker.Seek(offset, whence)
+}
+
+func (f fromIOFSFile) Write(p []byte) (n int, err error) {
+	return -1, notImplemented("write", f.name)
+}
+
+func (f fromIOFSFile) WriteAt(p []byte, off int64) (n int, err error) {
+	return -1, notImplemented("writeat", f.name)
+}
+
+func (f fromIOFSFile) Name() string { return f.name }
+
+func (f fromIOFSFile) Readdir(count int) ([]os.FileInfo, error) {
+	rdfile, ok := f.File.(fs.ReadDirFile)
+	if !ok {
+		return nil, notImplemented("readdir", f.name)
+	}
+
+	entries, err := rdfile.ReadDir(count)
+	if err != nil {
+		return nil, err
+	}
+
+	ret := make([]os.FileInfo, len(entries))
+	for i := range entries {
+		ret[i], err = entries[i].Info()
+
+		if err != nil {
+			return nil, err
+		}
+	}
+
+	return ret, nil
+}
+
+func (f fromIOFSFile) Readdirnames(n int) ([]string, error) {
+	rdfile, ok := f.File.(fs.ReadDirFile)
+	if !ok {
+		return nil, notImplemented("readdir", f.name)
+	}
+
+	entries, err := rdfile.ReadDir(n)
+	if err != nil {
+		return nil, err
+	}
+
+	ret := make([]string, len(entries))
+	for i := range entries {
+		ret[i] = entries[i].Name()
+	}
+
+	return ret, nil
+}
+
+func (f fromIOFSFile) Sync() error { return nil }
+
+func (f fromIOFSFile) Truncate(size int64) error {
+	return notImplemented("truncate", f.name)
+}
+
+func (f fromIOFSFile) WriteString(s string) (ret int, err error) {
+	return -1, notImplemented("writestring", f.name)
+}
+
+func notImplemented(op, path string) error {
+	return &fs.PathError{Op: op, Path: path, Err: fs.ErrPermission}
+}

vendor/github.com/spf13/afero/ioutil.go

@@ -0,0 +1,243 @@
+// Copyright ©2015 The Go Authors
+// Copyright ©2015 Steve Francia <spf@spf13.com>
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package afero
+
+import (
+	"bytes"
+	"io"
+	"os"
+	"path/filepath"
+	"sort"
+	"strconv"
+	"strings"
+	"sync"
+	"time"
+)
+
+// byName implements sort.Interface.
+type byName []os.FileInfo
+
+func (f byName) Len() int           { return len(f) }
+func (f byName) Less(i, j int) bool { return f[i].Name() < f[j].Name() }
+func (f byName) Swap(i, j int)      { f[i], f[j] = f[j], f[i] }
+
+// ReadDir reads the directory named by dirname and returns
+// a list of sorted directory entries.
+func (a Afero) ReadDir(dirname string) ([]os.FileInfo, error) {
+	return ReadDir(a.Fs, dirname)
+}
+
+func ReadDir(fs Fs, dirname string) ([]os.FileInfo, error) {
+	f, err := fs.Open(dirname)
+	if err != nil {
+		return nil, err
+	}
+	list, err := f.Readdir(-1)
+	f.Close()
+	if err != nil {
+		return nil, err
+	}
+	sort.Sort(byName(list))
+	return list, nil
+}
+
+// ReadFile reads the file named by filename and returns the contents.
+// A successful call returns err == nil, not err == EOF. Because ReadFile
+// reads the whole file, it does not treat an EOF from Read as an error
+// to be reported.
+func (a Afero) ReadFile(filename string) ([]byte, error) {
+	return ReadFile(a.Fs, filename)
+}
+
+func ReadFile(fs Fs, filename string) ([]byte, error) {
+	f, err := fs.Open(filename)
+	if err != nil {
+		return nil, err
+	}
+	defer f.Close()
+	// It's a good but not certain bet that FileInfo will tell us exactly how much to
+	// read, so let's try it but be prepared for the answer to be wrong.
+	var n int64
+
+	if fi, err := f.Stat(); err == nil {
+		// Don't preallocate a huge buffer, just in case.
+		if size := fi.Size(); size < 1e9 {
+			n = size
+		}
+	}
+	// As initial capacity for readAll, use n + a little extra in case Size is zero,
+	// and to avoid another allocation after Read has filled the buffer.  The readAll
+	// call will read into its allocated internal buffer cheaply.  If the size was
+	// wrong, we'll either waste some space off the end or reallocate as needed, but
+	// in the overwhelmingly common case we'll get it just right.
+	return readAll(f, n+bytes.MinRead)
+}
+
+// readAll reads from r until an error or EOF and returns the data it read
+// from the internal buffer allocated with a specified capacity.
+func readAll(r io.Reader, capacity int64) (b []byte, err error) {
+	buf := bytes.NewBuffer(make([]byte, 0, capacity))
+	// If the buffer overflows, we will get bytes.ErrTooLarge.
+	// Return that as an error. Any other panic remains.
+	defer func() {
+		e := recover()
+		if e == nil {
+			return
+		}
+		if panicErr, ok := e.(error); ok && panicErr == bytes.ErrTooLarge {
+			err = panicErr
+		} else {
+			panic(e)
+		}
+	}()
+	_, err = buf.ReadFrom(r)
+	return buf.Bytes(), err
+}
+
+// ReadAll reads from r until an error or EOF and returns the data it read.
+// A successful call returns err == nil, not err == EOF. Because ReadAll is
+// defined to read from src until EOF, it does not treat an EOF from Read
+// as an error to be reported.
+func ReadAll(r io.Reader) ([]byte, error) {
+	return readAll(r, bytes.MinRead)
+}
+
+// WriteFile writes data to a file named by filename.
+// If the file does not exist, WriteFile creates it with permissions perm;
+// otherwise WriteFile truncates it before writing.
+func (a Afero) WriteFile(filename string, data []byte, perm os.FileMode) error {
+	return WriteFile(a.Fs, filename, data, perm)
+}
+
+func WriteFile(fs Fs, filename string, data []byte, perm os.FileMode) error {
+	f, err := fs.OpenFile(filename, os.O_WRONLY|os.O_CREATE|os.O_TRUNC, perm)
+	if err != nil {
+		return err
+	}
+	n, err := f.Write(data)
+	if err == nil && n < len(data) {
+		err = io.ErrShortWrite
+	}
+	if err1 := f.Close(); err == nil {
+		err = err1
+	}
+	return err
+}
+
+// Random number state.
+// We generate random temporary file names so that there's a good
+// chance the file doesn't exist yet - keeps the number of tries in
+// TempFile to a minimum.
+var (
+	randNum uint32
+	randmu  sync.Mutex
+)
+
+func reseed() uint32 {
+	return uint32(time.Now().UnixNano() + int64(os.Getpid()))
+}
+
+func nextRandom() string {
+	randmu.Lock()
+	r := randNum
+	if r == 0 {
+		r = reseed()
+	}
+	r = r*1664525 + 1013904223 // constants from Numerical Recipes
+	randNum = r
+	randmu.Unlock()
+	return strconv.Itoa(int(1e9 + r%1e9))[1:]
+}
+
+// TempFile creates a new temporary file in the directory dir,
+// opens the file for reading and writing, and returns the resulting *os.File.
+// The filename is generated by taking pattern and adding a random
+// string to the end. If pattern includes a "*", the random string
+// replaces the last "*".
+// If dir is the empty string, TempFile uses the default directory
+// for temporary files (see os.TempDir).
+// Multiple programs calling TempFile simultaneously
+// will not choose the same file. The caller can use f.Name()
+// to find the pathname of the file. It is the caller's responsibility
+// to remove the file when no longer needed.
+func (a Afero) TempFile(dir, pattern string) (f File, err error) {
+	return TempFile(a.Fs, dir, pattern)
+}
+
+func TempFile(fs Fs, dir, pattern string) (f File, err error) {
+	if dir == "" {
+		dir = os.TempDir()
+	}
+
+	var prefix, suffix string
+	if pos := strings.LastIndex(pattern, "*"); pos != -1 {
+		prefix, suffix = pattern[:pos], pattern[pos+1:]
+	} else {
+		prefix = pattern
+	}
+
+	nconflict := 0
+	for i := 0; i < 10000; i++ {
+		name := filepath.Join(dir, prefix+nextRandom()+suffix)
+		f, err = fs.OpenFile(name, os.O_RDWR|os.O_CREATE|os.O_EXCL, 0o600)
+		if os.IsExist(err) {
+			if nconflict++; nconflict > 10 {
+				randmu.Lock()
+				randNum = reseed()
+				randmu.Unlock()
+			}
+			continue
+		}
+		break
+	}
+	return
+}
+
+// TempDir creates a new temporary directory in the directory dir
+// with a name beginning with prefix and returns the path of the
+// new directory.  If dir is the empty string, TempDir uses the
+// default directory for temporary files (see os.TempDir).
+// Multiple programs calling TempDir simultaneously
+// will not choose the same directory.  It is the caller's responsibility
+// to remove the directory when no longer needed.
+func (a Afero) TempDir(dir, prefix string) (name string, err error) {
+	return TempDir(a.Fs, dir, prefix)
+}
+
+func TempDir(fs Fs, dir, prefix string) (name string, err error) {
+	if dir == "" {
+		dir = os.TempDir()
+	}
+
+	nconflict := 0
+	for i := 0; i < 10000; i++ {
+		try := filepath.Join(dir, prefix+nextRandom())
+		err = fs.Mkdir(try, 0o700)
+		if os.IsExist(err) {
+			if nconflict++; nconflict > 10 {
+				randmu.Lock()
+				randNum = reseed()
+				randmu.Unlock()
+			}
+			continue
+		}
+		if err == nil {
+			name = try
+		}
+		break
+	}
+	return
+}

vendor/github.com/spf13/afero/lstater.go

@@ -0,0 +1,27 @@
+// Copyright © 2018 Steve Francia <spf@spf13.com>.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package afero
+
+import (
+	"os"
+)
+
+// Lstater is an optional interface in Afero. It is only implemented by the
+// filesystems saying so.
+// It will call Lstat if the filesystem iself is, or it delegates to, the os filesystem.
+// Else it will call Stat.
+// In addtion to the FileInfo, it will return a boolean telling whether Lstat was called or not.
+type Lstater interface {
+	LstatIfPossible(name string) (os.FileInfo, bool, error)
+}

vendor/github.com/spf13/afero/match.go

@@ -0,0 +1,110 @@
+// Copyright © 2014 Steve Francia <spf@spf13.com>.
+// Copyright 2009 The Go Authors. All rights reserved.
+
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package afero
+
+import (
+	"path/filepath"
+	"sort"
+	"strings"
+)
+
+// Glob returns the names of all files matching pattern or nil
+// if there is no matching file. The syntax of patterns is the same
+// as in Match. The pattern may describe hierarchical names such as
+// /usr/*/bin/ed (assuming the Separator is '/').
+//
+// Glob ignores file system errors such as I/O errors reading directories.
+// The only possible returned error is ErrBadPattern, when pattern
+// is malformed.
+//
+// This was adapted from (http://golang.org/pkg/path/filepath) and uses several
+// built-ins from that package.
+func Glob(fs Fs, pattern string) (matches []string, err error) {
+	if !hasMeta(pattern) {
+		// Lstat not supported by a ll filesystems.
+		if _, err = lstatIfPossible(fs, pattern); err != nil {
+			return nil, nil
+		}
+		return []string{pattern}, nil
+	}
+
+	dir, file := filepath.Split(pattern)
+	switch dir {
+	case "":
+		dir = "."
+	case string(filepath.Separator):
+	// nothing
+	default:
+		dir = dir[0 : len(dir)-1] // chop off trailing separator
+	}
+
+	if !hasMeta(dir) {
+		return glob(fs, dir, file, nil)
+	}
+
+	var m []string
+	m, err = Glob(fs, dir)
+	if err != nil {
+		return
+	}
+	for _, d := range m {
+		matches, err = glob(fs, d, file, matches)
+		if err != nil {
+			return
+		}
+	}
+	return
+}
+
+// glob searches for files matching pattern in the directory dir
+// and appends them to matches. If the directory cannot be
+// opened, it returns the existing matches. New matches are
+// added in lexicographical order.
+func glob(fs Fs, dir, pattern string, matches []string) (m []string, e error) {
+	m = matches
+	fi, err := fs.Stat(dir)
+	if err != nil {
+		return
+	}
+	if !fi.IsDir() {
+		return
+	}
+	d, err := fs.Open(dir)
+	if err != nil {
+		return
+	}
+	defer d.Close()
+
+	names, _ := d.Readdirnames(-1)
+	sort.Strings(names)
+
+	for _, n := range names {
+		matched, err := filepath.Match(pattern, n)
+		if err != nil {
+			return m, err
+		}
+		if matched {
+			m = append(m, filepath.Join(dir, n))
+		}
+	}
+	return
+}
+
+// hasMeta reports whether path contains any of the magic characters
+// recognized by Match.
+func hasMeta(path string) bool {
+	// TODO(niemeyer): Should other magic characters be added here?
+	return strings.ContainsAny(path, "*?[")
+}

vendor/github.com/spf13/afero/mem/dir.go

@@ -0,0 +1,37 @@
+// Copyright © 2014 Steve Francia <spf@spf13.com>.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package mem
+
+type Dir interface {
+	Len() int
+	Names() []string
+	Files() []*FileData
+	Add(*FileData)
+	Remove(*FileData)
+}
+
+func RemoveFromMemDir(dir *FileData, f *FileData) {
+	dir.memDir.Remove(f)
+}
+
+func AddToMemDir(dir *FileData, f *FileData) {
+	dir.memDir.Add(f)
+}
+
+func InitializeDir(d *FileData) {
+	if d.memDir == nil {
+		d.dir = true
+		d.memDir = &DirMap{}
+	}
+}

vendor/github.com/spf13/afero/mem/dirmap.go

@@ -0,0 +1,43 @@
+// Copyright © 2015 Steve Francia <spf@spf13.com>.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package mem
+
+import "sort"
+
+type DirMap map[string]*FileData
+
+func (m DirMap) Len() int           { return len(m) }
+func (m DirMap) Add(f *FileData)    { m[f.name] = f }
+func (m DirMap) Remove(f *FileData) { delete(m, f.name) }
+func (m DirMap) Files() (files []*FileData) {
+	for _, f := range m {
+		files = append(files, f)
+	}
+	sort.Sort(filesSorter(files))
+	return files
+}
+
+// implement sort.Interface for []*FileData
+type filesSorter []*FileData
+
+func (s filesSorter) Len() int           { return len(s) }
+func (s filesSorter) Swap(i, j int)      { s[i], s[j] = s[j], s[i] }
+func (s filesSorter) Less(i, j int) bool { return s[i].name < s[j].name }
+
+func (m DirMap) Names() (names []string) {
+	for x := range m {
+		names = append(names, x)
+	}
+	return names
+}

vendor/github.com/spf13/afero/mem/file.go

@@ -0,0 +1,359 @@
+// Copyright © 2015 Steve Francia <spf@spf13.com>.
+// Copyright 2013 tsuru authors. All rights reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package mem
+
+import (
+	"bytes"
+	"errors"
+	"io"
+	"io/fs"
+	"os"
+	"path/filepath"
+	"sync"
+	"sync/atomic"
+	"time"
+
+	"github.com/spf13/afero/internal/common"
+)
+
+const FilePathSeparator = string(filepath.Separator)
+
+var _ fs.ReadDirFile = &File{}
+
+type File struct {
+	// atomic requires 64-bit alignment for struct field access
+	at           int64
+	readDirCount int64
+	closed       bool
+	readOnly     bool
+	fileData     *FileData
+}
+
+func NewFileHandle(data *FileData) *File {
+	return &File{fileData: data}
+}
+
+func NewReadOnlyFileHandle(data *FileData) *File {
+	return &File{fileData: data, readOnly: true}
+}
+
+func (f File) Data() *FileData {
+	return f.fileData
+}
+
+type FileData struct {
+	sync.Mutex
+	name    string
+	data    []byte
+	memDir  Dir
+	dir     bool
+	mode    os.FileMode
+	modtime time.Time
+	uid     int
+	gid     int
+}
+
+func (d *FileData) Name() string {
+	d.Lock()
+	defer d.Unlock()
+	return d.name
+}
+
+func CreateFile(name string) *FileData {
+	return &FileData{name: name, mode: os.ModeTemporary, modtime: time.Now()}
+}
+
+func CreateDir(name string) *FileData {
+	return &FileData{name: name, memDir: &DirMap{}, dir: true, modtime: time.Now()}
+}
+
+func ChangeFileName(f *FileData, newname string) {
+	f.Lock()
+	f.name = newname
+	f.Unlock()
+}
+
+func SetMode(f *FileData, mode os.FileMode) {
+	f.Lock()
+	f.mode = mode
+	f.Unlock()
+}
+
+func SetModTime(f *FileData, mtime time.Time) {
+	f.Lock()
+	setModTime(f, mtime)
+	f.Unlock()
+}
+
+func setModTime(f *FileData, mtime time.Time) {
+	f.modtime = mtime
+}
+
+func SetUID(f *FileData, uid int) {
+	f.Lock()
+	f.uid = uid
+	f.Unlock()
+}
+
+func SetGID(f *FileData, gid int) {
+	f.Lock()
+	f.gid = gid
+	f.Unlock()
+}
+
+func GetFileInfo(f *FileData) *FileInfo {
+	return &FileInfo{f}
+}
+
+func (f *File) Open() error {
+	atomic.StoreInt64(&f.at, 0)
+	atomic.StoreInt64(&f.readDirCount, 0)
+	f.fileData.Lock()
+	f.closed = false
+	f.fileData.Unlock()
+	return nil
+}
+
+func (f *File) Close() error {
+	f.fileData.Lock()
+	f.closed = true
+	if !f.readOnly {
+		setModTime(f.fileData, time.Now())
+	}
+	f.fileData.Unlock()
+	return nil
+}
+
+func (f *File) Name() string {
+	return f.fileData.Name()
+}
+
+func (f *File) Stat() (os.FileInfo, error) {
+	return &FileInfo{f.fileData}, nil
+}
+
+func (f *File) Sync() error {
+	return nil
+}
+
+func (f *File) Readdir(count int) (res []os.FileInfo, err error) {
+	if !f.fileData.dir {
+		return nil, &os.PathError{Op: "readdir", Path: f.fileData.name, Err: errors.New("not a dir")}
+	}
+	var outLength int64
+
+	f.fileData.Lock()
+	files := f.fileData.memDir.Files()[f.readDirCount:]
+	if count > 0 {
+		if len(files) < count {
+			outLength = int64(len(files))
+		} else {
+			outLength = int64(count)
+		}
+		if len(files) == 0 {
+			err = io.EOF
+		}
+	} else {
+		outLength = int64(len(files))
+	}
+	f.readDirCount += outLength
+	f.fileData.Unlock()
+
+	res = make([]os.FileInfo, outLength)
+	for i := range res {
+		res[i] = &FileInfo{files[i]}
+	}
+
+	return res, err
+}
+
+func (f *File) Readdirnames(n int) (names []string, err error) {
+	fi, err := f.Readdir(n)
+	names = make([]string, len(fi))
+	for i, f := range fi {
+		_, names[i] = filepath.Split(f.Name())
+	}
+	return names, err
+}
+
+// Implements fs.ReadDirFile
+func (f *File) ReadDir(n int) ([]fs.DirEntry, error) {
+	fi, err := f.Readdir(n)
+	if err != nil {
+		return nil, err
+	}
+	di := make([]fs.DirEntry, len(fi))
+	for i, f := range fi {
+		di[i] = common.FileInfoDirEntry{FileInfo: f}
+	}
+	return di, nil
+}
+
+func (f *File) Read(b []byte) (n int, err error) {
+	f.fileData.Lock()
+	defer f.fileData.Unlock()
+	if f.closed {
+		return 0, ErrFileClosed
+	}
+	if len(b) > 0 && int(f.at) == len(f.fileData.data) {
+		return 0, io.EOF
+	}
+	if int(f.at) > len(f.fileData.data) {
+		return 0, io.ErrUnexpectedEOF
+	}
+	if len(f.fileData.data)-int(f.at) >= len(b) {
+		n = len(b)
+	} else {
+		n = len(f.fileData.data) - int(f.at)
+	}
+	copy(b, f.fileData.data[f.at:f.at+int64(n)])
+	atomic.AddInt64(&f.at, int64(n))
+	return
+}
+
+func (f *File) ReadAt(b []byte, off int64) (n int, err error) {
+	prev := atomic.LoadInt64(&f.at)
+	atomic.StoreInt64(&f.at, off)
+	n, err = f.Read(b)
+	atomic.StoreInt64(&f.at, prev)
+	return
+}
+
+func (f *File) Truncate(size int64) error {
+	if f.closed {
+		return ErrFileClosed
+	}
+	if f.readOnly {
+		return &os.PathError{Op: "truncate", Path: f.fileData.name, Err: errors.New("file handle is read only")}
+	}
+	if size < 0 {
+		return ErrOutOfRange
+	}
+	f.fileData.Lock()
+	defer f.fileData.Unlock()
+	if size > int64(len(f.fileData.data)) {
+		diff := size - int64(len(f.fileData.data))
+		f.fileData.data = append(f.fileData.data, bytes.Repeat([]byte{0o0}, int(diff))...)
+	} else {
+		f.fileData.data = f.fileData.data[0:size]
+	}
+	setModTime(f.fileData, time.Now())
+	return nil
+}
+
+func (f *File) Seek(offset int64, whence int) (int64, error) {
+	if f.closed {
+		return 0, ErrFileClosed
+	}
+	switch whence {
+	case io.SeekStart:
+		atomic.StoreInt64(&f.at, offset)
+	case io.SeekCurrent:
+		atomic.AddInt64(&f.at, offset)
+	case io.SeekEnd:
+		atomic.StoreInt64(&f.at, int64(len(f.fileData.data))+offset)
+	}
+	return f.at, nil
+}
+
+func (f *File) Write(b []byte) (n int, err error) {
+	if f.closed {
+		return 0, ErrFileClosed
+	}
+	if f.readOnly {
+		return 0, &os.PathError{Op: "write", Path: f.fileData.name, Err: errors.New("file handle is read only")}
+	}
+	n = len(b)
+	cur := atomic.LoadInt64(&f.at)
+	f.fileData.Lock()
+	defer f.fileData.Unlock()
+	diff := cur - int64(len(f.fileData.data))
+	var tail []byte
+	if n+int(cur) < len(f.fileData.data) {
+		tail = f.fileData.data[n+int(cur):]
+	}
+	if diff > 0 {
+		f.fileData.data = append(f.fileData.data, append(bytes.Repeat([]byte{0o0}, int(diff)), b...)...)
+		f.fileData.data = append(f.fileData.data, tail...)
+	} else {
+		f.fileData.data = append(f.fileData.data[:cur], b...)
+		f.fileData.data = append(f.fileData.data, tail...)
+	}
+	setModTime(f.fileData, time.Now())
+
+	atomic.AddInt64(&f.at, int64(n))
+	return
+}
+
+func (f *File) WriteAt(b []byte, off int64) (n int, err error) {
+	atomic.StoreInt64(&f.at, off)
+	return f.Write(b)
+}
+
+func (f *File) WriteString(s string) (ret int, err error) {
+	return f.Write([]byte(s))
+}
+
+func (f *File) Info() *FileInfo {
+	return &FileInfo{f.fileData}
+}
+
+type FileInfo struct {
+	*FileData
+}
+
+// Implements os.FileInfo
+func (s *FileInfo) Name() string {
+	s.Lock()
+	_, name := filepath.Split(s.name)
+	s.Unlock()
+	return name
+}
+
+func (s *FileInfo) Mode() os.FileMode {
+	s.Lock()
+	defer s.Unlock()
+	return s.mode
+}
+
+func (s *FileInfo) ModTime() time.Time {
+	s.Lock()
+	defer s.Unlock()
+	return s.modtime
+}
+
+func (s *FileInfo) IsDir() bool {
+	s.Lock()
+	defer s.Unlock()
+	return s.dir
+}
+func (s *FileInfo) Sys() interface{} { return nil }
+func (s *FileInfo) Size() int64 {
+	if s.IsDir() {
+		return int64(42)
+	}
+	s.Lock()
+	defer s.Unlock()
+	return int64(len(s.data))
+}
+
+var (
+	ErrFileClosed        = errors.New("File is closed")
+	ErrOutOfRange        = errors.New("out of range")
+	ErrTooLarge          = errors.New("too large")
+	ErrFileNotFound      = os.ErrNotExist
+	ErrFileExists        = os.ErrExist
+	ErrDestinationExists = os.ErrExist
+)

vendor/github.com/spf13/afero/memmap.go

@@ -0,0 +1,465 @@
+// Copyright © 2014 Steve Francia <spf@spf13.com>.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package afero
+
+import (
+	"fmt"
+	"io"
+
+	"log"
+	"os"
+	"path/filepath"
+
+	"sort"
+	"strings"
+	"sync"
+	"time"
+
+	"github.com/spf13/afero/mem"
+)
+
+const chmodBits = os.ModePerm | os.ModeSetuid | os.ModeSetgid | os.ModeSticky // Only a subset of bits are allowed to be changed. Documented under os.Chmod()
+
+type MemMapFs struct {
+	mu   sync.RWMutex
+	data map[string]*mem.FileData
+	init sync.Once
+}
+
+func NewMemMapFs() Fs {
+	return &MemMapFs{}
+}
+
+func (m *MemMapFs) getData() map[string]*mem.FileData {
+	m.init.Do(func() {
+		m.data = make(map[string]*mem.FileData)
+		// Root should always exist, right?
+		// TODO: what about windows?
+		root := mem.CreateDir(FilePathSeparator)
+		mem.SetMode(root, os.ModeDir|0o755)
+		m.data[FilePathSeparator] = root
+	})
+	return m.data
+}
+
+func (*MemMapFs) Name() string { return "MemMapFS" }
+
+func (m *MemMapFs) Create(name string) (File, error) {
+	name = normalizePath(name)
+	m.mu.Lock()
+	file := mem.CreateFile(name)
+	m.getData()[name] = file
+	m.registerWithParent(file, 0)
+	m.mu.Unlock()
+	return mem.NewFileHandle(file), nil
+}
+
+func (m *MemMapFs) unRegisterWithParent(fileName string) error {
+	f, err := m.lockfreeOpen(fileName)
+	if err != nil {
+		return err
+	}
+	parent := m.findParent(f)
+	if parent == nil {
+		log.Panic("parent of ", f.Name(), " is nil")
+	}
+
+	parent.Lock()
+	mem.RemoveFromMemDir(parent, f)
+	parent.Unlock()
+	return nil
+}
+
+func (m *MemMapFs) findParent(f *mem.FileData) *mem.FileData {
+	pdir, _ := filepath.Split(f.Name())
+	pdir = filepath.Clean(pdir)
+	pfile, err := m.lockfreeOpen(pdir)
+	if err != nil {
+		return nil
+	}
+	return pfile
+}
+
+func (m *MemMapFs) findDescendants(name string) []*mem.FileData {
+	fData := m.getData()
+	descendants := make([]*mem.FileData, 0, len(fData))
+	for p, dFile := range fData {
+		if strings.HasPrefix(p, name+FilePathSeparator) {
+			descendants = append(descendants, dFile)
+		}
+	}
+
+	sort.Slice(descendants, func(i, j int) bool {
+		cur := len(strings.Split(descendants[i].Name(), FilePathSeparator))
+		next := len(strings.Split(descendants[j].Name(), FilePathSeparator))
+		return cur < next
+	})
+
+	return descendants
+}
+
+func (m *MemMapFs) registerWithParent(f *mem.FileData, perm os.FileMode) {
+	if f == nil {
+		return
+	}
+	parent := m.findParent(f)
+	if parent == nil {
+		pdir := filepath.Dir(filepath.Clean(f.Name()))
+		err := m.lockfreeMkdir(pdir, perm)
+		if err != nil {
+			// log.Println("Mkdir error:", err)
+			return
+		}
+		parent, err = m.lockfreeOpen(pdir)
+		if err != nil {
+			// log.Println("Open after Mkdir error:", err)
+			return
+		}
+	}
+
+	parent.Lock()
+	mem.InitializeDir(parent)
+	mem.AddToMemDir(parent, f)
+	parent.Unlock()
+}
+
+func (m *MemMapFs) lockfreeMkdir(name string, perm os.FileMode) error {
+	name = normalizePath(name)
+	x, ok := m.getData()[name]
+	if ok {
+		// Only return ErrFileExists if it's a file, not a directory.
+		i := mem.FileInfo{FileData: x}
+		if !i.IsDir() {
+			return ErrFileExists
+		}
+	} else {
+		item := mem.CreateDir(name)
+		mem.SetMode(item, os.ModeDir|perm)
+		m.getData()[name] = item
+		m.registerWithParent(item, perm)
+	}
+	return nil
+}
+
+func (m *MemMapFs) Mkdir(name string, perm os.FileMode) error {
+	perm &= chmodBits
+	name = normalizePath(name)
+
+	m.mu.RLock()
+	_, ok := m.getData()[name]
+	m.mu.RUnlock()
+	if ok {
+		return &os.PathError{Op: "mkdir", Path: name, Err: ErrFileExists}
+	}
+
+	m.mu.Lock()
+	// Dobule check that it doesn't exist.
+	if _, ok := m.getData()[name]; ok {
+		m.mu.Unlock()
+		return &os.PathError{Op: "mkdir", Path: name, Err: ErrFileExists}
+	}
+	item := mem.CreateDir(name)
+	mem.SetMode(item, os.ModeDir|perm)
+	m.getData()[name] = item
+	m.registerWithParent(item, perm)
+	m.mu.Unlock()
+
+	return m.setFileMode(name, perm|os.ModeDir)
+}
+
+func (m *MemMapFs) MkdirAll(path string, perm os.FileMode) error {
+	err := m.Mkdir(path, perm)
+	if err != nil {
+		if err.(*os.PathError).Err == ErrFileExists {
+			return nil
+		}
+		return err
+	}
+	return nil
+}
+
+// Handle some relative paths
+func normalizePath(path string) string {
+	path = filepath.Clean(path)
+
+	switch path {
+	case ".":
+		return FilePathSeparator
+	case "..":
+		return FilePathSeparator
+	default:
+		return path
+	}
+}
+
+func (m *MemMapFs) Open(name string) (File, error) {
+	f, err := m.open(name)
+	if f != nil {
+		return mem.NewReadOnlyFileHandle(f), err
+	}
+	return nil, err
+}
+
+func (m *MemMapFs) openWrite(name string) (File, error) {
+	f, err := m.open(name)
+	if f != nil {
+		return mem.NewFileHandle(f), err
+	}
+	return nil, err
+}
+
+func (m *MemMapFs) open(name string) (*mem.FileData, error) {
+	name = normalizePath(name)
+
+	m.mu.RLock()
+	f, ok := m.getData()[name]
+	m.mu.RUnlock()
+	if !ok {
+		return nil, &os.PathError{Op: "open", Path: name, Err: ErrFileNotFound}
+	}
+	return f, nil
+}
+
+func (m *MemMapFs) lockfreeOpen(name string) (*mem.FileData, error) {
+	name = normalizePath(name)
+	f, ok := m.getData()[name]
+	if ok {
+		return f, nil
+	} else {
+		return nil, ErrFileNotFound
+	}
+}
+
+func (m *MemMapFs) OpenFile(name string, flag int, perm os.FileMode) (File, error) {
+	perm &= chmodBits
+	chmod := false
+	file, err := m.openWrite(name)
+	if err == nil && (flag&os.O_EXCL > 0) {
+		return nil, &os.PathError{Op: "open", Path: name, Err: ErrFileExists}
+	}
+	if os.IsNotExist(err) && (flag&os.O_CREATE > 0) {
+		file, err = m.Create(name)
+		chmod = true
+	}
+	if err != nil {
+		return nil, err
+	}
+	if flag == os.O_RDONLY {
+		file = mem.NewReadOnlyFileHandle(file.(*mem.File).Data())
+	}
+	if flag&os.O_APPEND > 0 {
+		_, err = file.Seek(0, io.SeekEnd)
+		if err != nil {
+			file.Close()
+			return nil, err
+		}
+	}
+	if flag&os.O_TRUNC > 0 && flag&(os.O_RDWR|os.O_WRONLY) > 0 {
+		err = file.Truncate(0)
+		if err != nil {
+			file.Close()
+			return nil, err
+		}
+	}
+	if chmod {
+		return file, m.setFileMode(name, perm)
+	}
+	return file, nil
+}
+
+func (m *MemMapFs) Remove(name string) error {
+	name = normalizePath(name)
+
+	m.mu.Lock()
+	defer m.mu.Unlock()
+
+	if _, ok := m.getData()[name]; ok {
+		err := m.unRegisterWithParent(name)
+		if err != nil {
+			return &os.PathError{Op: "remove", Path: name, Err: err}
+		}
+		delete(m.getData(), name)
+	} else {
+		return &os.PathError{Op: "remove", Path: name, Err: os.ErrNotExist}
+	}
+	return nil
+}
+
+func (m *MemMapFs) RemoveAll(path string) error {
+	path = normalizePath(path)
+	m.mu.Lock()
+	m.unRegisterWithParent(path)
+	m.mu.Unlock()
+
+	m.mu.RLock()
+	defer m.mu.RUnlock()
+
+	for p := range m.getData() {
+		if p == path || strings.HasPrefix(p, path+FilePathSeparator) {
+			m.mu.RUnlock()
+			m.mu.Lock()
+			delete(m.getData(), p)
+			m.mu.Unlock()
+			m.mu.RLock()
+		}
+	}
+	return nil
+}
+
+func (m *MemMapFs) Rename(oldname, newname string) error {
+	oldname = normalizePath(oldname)
+	newname = normalizePath(newname)
+
+	if oldname == newname {
+		return nil
+	}
+
+	m.mu.RLock()
+	defer m.mu.RUnlock()
+	if _, ok := m.getData()[oldname]; ok {
+		m.mu.RUnlock()
+		m.mu.Lock()
+		err := m.unRegisterWithParent(oldname)
+		if err != nil {
+			return err
+		}
+
+		fileData := m.getData()[oldname]
+		mem.ChangeFileName(fileData, newname)
+		m.getData()[newname] = fileData
+
+		err = m.renameDescendants(oldname, newname)
+		if err != nil {
+			return err
+		}
+
+		delete(m.getData(), oldname)
+
+		m.registerWithParent(fileData, 0)
+		m.mu.Unlock()
+		m.mu.RLock()
+	} else {
+		return &os.PathError{Op: "rename", Path: oldname, Err: ErrFileNotFound}
+	}
+	return nil
+}
+
+func (m *MemMapFs) renameDescendants(oldname, newname string) error {
+	descendants := m.findDescendants(oldname)
+	removes := make([]string, 0, len(descendants))
+	for _, desc := range descendants {
+		descNewName := strings.Replace(desc.Name(), oldname, newname, 1)
+		err := m.unRegisterWithParent(desc.Name())
+		if err != nil {
+			return err
+		}
+
+		removes = append(removes, desc.Name())
+		mem.ChangeFileName(desc, descNewName)
+		m.getData()[descNewName] = desc
+
+		m.registerWithParent(desc, 0)
+	}
+	for _, r := range removes {
+		delete(m.getData(), r)
+	}
+
+	return nil
+}
+
+func (m *MemMapFs) LstatIfPossible(name string) (os.FileInfo, bool, error) {
+	fileInfo, err := m.Stat(name)
+	return fileInfo, false, err
+}
+
+func (m *MemMapFs) Stat(name string) (os.FileInfo, error) {
+	f, err := m.Open(name)
+	if err != nil {
+		return nil, err
+	}
+	fi := mem.GetFileInfo(f.(*mem.File).Data())
+	return fi, nil
+}
+
+func (m *MemMapFs) Chmod(name string, mode os.FileMode) error {
+	mode &= chmodBits
+
+	m.mu.RLock()
+	f, ok := m.getData()[name]
+	m.mu.RUnlock()
+	if !ok {
+		return &os.PathError{Op: "chmod", Path: name, Err: ErrFileNotFound}
+	}
+	prevOtherBits := mem.GetFileInfo(f).Mode() & ^chmodBits
+
+	mode = prevOtherBits | mode
+	return m.setFileMode(name, mode)
+}
+
+func (m *MemMapFs) setFileMode(name string, mode os.FileMode) error {
+	name = normalizePath(name)
+
+	m.mu.RLock()
+	f, ok := m.getData()[name]
+	m.mu.RUnlock()
+	if !ok {
+		return &os.PathError{Op: "chmod", Path: name, Err: ErrFileNotFound}
+	}
+
+	m.mu.Lock()
+	mem.SetMode(f, mode)
+	m.mu.Unlock()
+
+	return nil
+}
+
+func (m *MemMapFs) Chown(name string, uid, gid int) error {
+	name = normalizePath(name)
+
+	m.mu.RLock()
+	f, ok := m.getData()[name]
+	m.mu.RUnlock()
+	if !ok {
+		return &os.PathError{Op: "chown", Path: name, Err: ErrFileNotFound}
+	}
+
+	mem.SetUID(f, uid)
+	mem.SetGID(f, gid)
+
+	return nil
+}
+
+func (m *MemMapFs) Chtimes(name string, atime time.Time, mtime time.Time) error {
+	name = normalizePath(name)
+
+	m.mu.RLock()
+	f, ok := m.getData()[name]
+	m.mu.RUnlock()
+	if !ok {
+		return &os.PathError{Op: "chtimes", Path: name, Err: ErrFileNotFound}
+	}
+
+	m.mu.Lock()
+	mem.SetModTime(f, mtime)
+	m.mu.Unlock()
+
+	return nil
+}
+
+func (m *MemMapFs) List() {
+	for _, x := range m.data {
+		y := mem.FileInfo{FileData: x}
+		fmt.Println(x.Name(), y.Size())
+	}
+}

vendor/github.com/spf13/afero/os.go

@@ -0,0 +1,113 @@
+// Copyright © 2014 Steve Francia <spf@spf13.com>.
+// Copyright 2013 tsuru authors. All rights reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package afero
+
+import (
+	"os"
+	"time"
+)
+
+var _ Lstater = (*OsFs)(nil)
+
+// OsFs is a Fs implementation that uses functions provided by the os package.
+//
+// For details in any method, check the documentation of the os package
+// (http://golang.org/pkg/os/).
+type OsFs struct{}
+
+func NewOsFs() Fs {
+	return &OsFs{}
+}
+
+func (OsFs) Name() string { return "OsFs" }
+
+func (OsFs) Create(name string) (File, error) {
+	f, e := os.Create(name)
+	if f == nil {
+		// while this looks strange, we need to return a bare nil (of type nil) not
+		// a nil value of type *os.File or nil won't be nil
+		return nil, e
+	}
+	return f, e
+}
+
+func (OsFs) Mkdir(name string, perm os.FileMode) error {
+	return os.Mkdir(name, perm)
+}
+
+func (OsFs) MkdirAll(path string, perm os.FileMode) error {
+	return os.MkdirAll(path, perm)
+}
+
+func (OsFs) Open(name string) (File, error) {
+	f, e := os.Open(name)
+	if f == nil {
+		// while this looks strange, we need to return a bare nil (of type nil) not
+		// a nil value of type *os.File or nil won't be nil
+		return nil, e
+	}
+	return f, e
+}
+
+func (OsFs) OpenFile(name string, flag int, perm os.FileMode) (File, error) {
+	f, e := os.OpenFile(name, flag, perm)
+	if f == nil {
+		// while this looks strange, we need to return a bare nil (of type nil) not
+		// a nil value of type *os.File or nil won't be nil
+		return nil, e
+	}
+	return f, e
+}
+
+func (OsFs) Remove(name string) error {
+	return os.Remove(name)
+}
+
+func (OsFs) RemoveAll(path string) error {
+	return os.RemoveAll(path)
+}
+
+func (OsFs) Rename(oldname, newname string) error {
+	return os.Rename(oldname, newname)
+}
+
+func (OsFs) Stat(name string) (os.FileInfo, error) {
+	return os.Stat(name)
+}
+
+func (OsFs) Chmod(name string, mode os.FileMode) error {
+	return os.Chmod(name, mode)
+}
+
+func (OsFs) Chown(name string, uid, gid int) error {
+	return os.Chown(name, uid, gid)
+}
+
+func (OsFs) Chtimes(name string, atime time.Time, mtime time.Time) error {
+	return os.Chtimes(name, atime, mtime)
+}
+
+func (OsFs) LstatIfPossible(name string) (os.FileInfo, bool, error) {
+	fi, err := os.Lstat(name)
+	return fi, true, err
+}
+
+func (OsFs) SymlinkIfPossible(oldname, newname string) error {
+	return os.Symlink(oldname, newname)
+}
+
+func (OsFs) ReadlinkIfPossible(name string) (string, error) {
+	return os.Readlink(name)
+}

vendor/github.com/spf13/afero/path.go

@@ -0,0 +1,106 @@
+// Copyright ©2015 The Go Authors
+// Copyright ©2015 Steve Francia <spf@spf13.com>
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package afero
+
+import (
+	"os"
+	"path/filepath"
+	"sort"
+)
+
+// readDirNames reads the directory named by dirname and returns
+// a sorted list of directory entries.
+// adapted from https://golang.org/src/path/filepath/path.go
+func readDirNames(fs Fs, dirname string) ([]string, error) {
+	f, err := fs.Open(dirname)
+	if err != nil {
+		return nil, err
+	}
+	names, err := f.Readdirnames(-1)
+	f.Close()
+	if err != nil {
+		return nil, err
+	}
+	sort.Strings(names)
+	return names, nil
+}
+
+// walk recursively descends path, calling walkFn
+// adapted from https://golang.org/src/path/filepath/path.go
+func walk(fs Fs, path string, info os.FileInfo, walkFn filepath.WalkFunc) error {
+	err := walkFn(path, info, nil)
+	if err != nil {
+		if info.IsDir() && err == filepath.SkipDir {
+			return nil
+		}
+		return err
+	}
+
+	if !info.IsDir() {
+		return nil
+	}
+
+	names, err := readDirNames(fs, path)
+	if err != nil {
+		return walkFn(path, info, err)
+	}
+
+	for _, name := range names {
+		filename := filepath.Join(path, name)
+		fileInfo, err := lstatIfPossible(fs, filename)
+		if err != nil {
+			if err := walkFn(filename, fileInfo, err); err != nil && err != filepath.SkipDir {
+				return err
+			}
+		} else {
+			err = walk(fs, filename, fileInfo, walkFn)
+			if err != nil {
+				if !fileInfo.IsDir() || err != filepath.SkipDir {
+					return err
+				}
+			}
+		}
+	}
+	return nil
+}
+
+// if the filesystem supports it, use Lstat, else use fs.Stat
+func lstatIfPossible(fs Fs, path string) (os.FileInfo, error) {
+	if lfs, ok := fs.(Lstater); ok {
+		fi, _, err := lfs.LstatIfPossible(path)
+		return fi, err
+	}
+	return fs.Stat(path)
+}
+
+// Walk walks the file tree rooted at root, calling walkFn for each file or
+// directory in the tree, including root. All errors that arise visiting files
+// and directories are filtered by walkFn. The files are walked in lexical
+// order, which makes the output deterministic but means that for very
+// large directories Walk can be inefficient.
+// Walk does not follow symbolic links.
+
+func (a Afero) Walk(root string, walkFn filepath.WalkFunc) error {
+	return Walk(a.Fs, root, walkFn)
+}
+
+func Walk(fs Fs, root string, walkFn filepath.WalkFunc) error {
+	info, err := lstatIfPossible(fs, root)
+	if err != nil {
+		return walkFn(root, nil, err)
+	}
+	return walk(fs, root, info, walkFn)
+}

vendor/github.com/spf13/afero/readonlyfs.go

@@ -0,0 +1,96 @@
+package afero
+
+import (
+	"os"
+	"syscall"
+	"time"
+)
+
+var _ Lstater = (*ReadOnlyFs)(nil)
+
+type ReadOnlyFs struct {
+	source Fs
+}
+
+func NewReadOnlyFs(source Fs) Fs {
+	return &ReadOnlyFs{source: source}
+}
+
+func (r *ReadOnlyFs) ReadDir(name string) ([]os.FileInfo, error) {
+	return ReadDir(r.source, name)
+}
+
+func (r *ReadOnlyFs) Chtimes(n string, a, m time.Time) error {
+	return syscall.EPERM
+}
+
+func (r *ReadOnlyFs) Chmod(n string, m os.FileMode) error {
+	return syscall.EPERM
+}
+
+func (r *ReadOnlyFs) Chown(n string, uid, gid int) error {
+	return syscall.EPERM
+}
+
+func (r *ReadOnlyFs) Name() string {
+	return "ReadOnlyFilter"
+}
+
+func (r *ReadOnlyFs) Stat(name string) (os.FileInfo, error) {
+	return r.source.Stat(name)
+}
+
+func (r *ReadOnlyFs) LstatIfPossible(name string) (os.FileInfo, bool, error) {
+	if lsf, ok := r.source.(Lstater); ok {
+		return lsf.LstatIfPossible(name)
+	}
+	fi, err := r.Stat(name)
+	return fi, false, err
+}
+
+func (r *ReadOnlyFs) SymlinkIfPossible(oldname, newname string) error {
+	return &os.LinkError{Op: "symlink", Old: oldname, New: newname, Err: ErrNoSymlink}
+}
+
+func (r *ReadOnlyFs) ReadlinkIfPossible(name string) (string, error) {
+	if srdr, ok := r.source.(LinkReader); ok {
+		return srdr.ReadlinkIfPossible(name)
+	}
+
+	return "", &os.PathError{Op: "readlink", Path: name, Err: ErrNoReadlink}
+}
+
+func (r *ReadOnlyFs) Rename(o, n string) error {
+	return syscall.EPERM
+}
+
+func (r *ReadOnlyFs) RemoveAll(p string) error {
+	return syscall.EPERM
+}
+
+func (r *ReadOnlyFs) Remove(n string) error {
+	return syscall.EPERM
+}
+
+func (r *ReadOnlyFs) OpenFile(name string, flag int, perm os.FileMode) (File, error) {
+	if flag&(os.O_WRONLY|syscall.O_RDWR|os.O_APPEND|os.O_CREATE|os.O_TRUNC) != 0 {
+		return nil, syscall.EPERM
+	}
+	return r.source.OpenFile(name, flag, perm)
+}
+
+func (r *ReadOnlyFs) Open(n string) (File, error) {
+	return r.source.Open(n)
+}
+
+func (r *ReadOnlyFs) Mkdir(n string, p os.FileMode) error {
+	return syscall.EPERM
+}
+
+func (r *ReadOnlyFs) MkdirAll(n string, p os.FileMode) error {
+	return syscall.EPERM
+}
+
+func (r *ReadOnlyFs) Create(n string) (File, error) {
+	return nil, syscall.EPERM
+}

vendor/github.com/spf13/afero/regexpfs.go

@@ -0,0 +1,223 @@
+package afero
+
+import (
+	"os"
+	"regexp"
+	"syscall"
+	"time"
+)
+
+// The RegexpFs filters files (not directories) by regular expression. Only
+// files matching the given regexp will be allowed, all others get a ENOENT error (
+// "No such file or directory").
+type RegexpFs struct {
+	re     *regexp.Regexp
+	source Fs
+}
+
+func NewRegexpFs(source Fs, re *regexp.Regexp) Fs {
+	return &RegexpFs{source: source, re: re}
+}
+
+type RegexpFile struct {
+	f  File
+	re *regexp.Regexp
+}
+
+func (r *RegexpFs) matchesName(name string) error {
+	if r.re == nil {
+		return nil
+	}
+	if r.re.MatchString(name) {
+		return nil
+	}
+	return syscall.ENOENT
+}
+
+func (r *RegexpFs) dirOrMatches(name string) error {
+	dir, err := IsDir(r.source, name)
+	if err != nil {
+		return err
+	}
+	if dir {
+		return nil
+	}
+	return r.matchesName(name)
+}
+
+func (r *RegexpFs) Chtimes(name string, a, m time.Time) error {
+	if err := r.dirOrMatches(name); err != nil {
+		return err
+	}
+	return r.source.Chtimes(name, a, m)
+}
+
+func (r *RegexpFs) Chmod(name string, mode os.FileMode) error {
+	if err := r.dirOrMatches(name); err != nil {
+		return err
+	}
+	return r.source.Chmod(name, mode)
+}
+
+func (r *RegexpFs) Chown(name string, uid, gid int) error {
+	if err := r.dirOrMatches(name); err != nil {
+		return err
+	}
+	return r.source.Chown(name, uid, gid)
+}
+
+func (r *RegexpFs) Name() string {
+	return "RegexpFs"
+}
+
+func (r *RegexpFs) Stat(name string) (os.FileInfo, error) {
+	if err := r.dirOrMatches(name); err != nil {
+		return nil, err
+	}
+	return r.source.Stat(name)
+}
+
+func (r *RegexpFs) Rename(oldname, newname string) error {
+	dir, err := IsDir(r.source, oldname)
+	if err != nil {
+		return err
+	}
+	if dir {
+		return nil
+	}
+	if err := r.matchesName(oldname); err != nil {
+		return err
+	}
+	if err := r.matchesName(newname); err != nil {
+		return err
+	}
+	return r.source.Rename(oldname, newname)
+}
+
+func (r *RegexpFs) RemoveAll(p string) error {
+	dir, err := IsDir(r.source, p)
+	if err != nil {
+		return err
+	}
+	if !dir {
+		if err := r.matchesName(p); err != nil {
+			return err
+		}
+	}
+	return r.source.RemoveAll(p)
+}
+
+func (r *RegexpFs) Remove(name string) error {
+	if err := r.dirOrMatches(name); err != nil {
+		return err
+	}
+	return r.source.Remove(name)
+}
+
+func (r *RegexpFs) OpenFile(name string, flag int, perm os.FileMode) (File, error) {
+	if err := r.dirOrMatches(name); err != nil {
+		return nil, err
+	}
+	return r.source.OpenFile(name, flag, perm)
+}
+
+func (r *RegexpFs) Open(name string) (File, error) {
+	dir, err := IsDir(r.source, name)
+	if err != nil {
+		return nil, err
+	}
+	if !dir {
+		if err := r.matchesName(name); err != nil {
+			return nil, err
+		}
+	}
+	f, err := r.source.Open(name)
+	if err != nil {
+		return nil, err
+	}
+	return &RegexpFile{f: f, re: r.re}, nil
+}
+
+func (r *RegexpFs) Mkdir(n string, p os.FileMode) error {
+	return r.source.Mkdir(n, p)
+}
+
+func (r *RegexpFs) MkdirAll(n string, p os.FileMode) error {
+	return r.source.MkdirAll(n, p)
+}
+
+func (r *RegexpFs) Create(name string) (File, error) {
+	if err := r.matchesName(name); err != nil {
+		return nil, err
+	}
+	return r.source.Create(name)
+}
+
+func (f *RegexpFile) Close() error {
+	return f.f.Close()
+}
+
+func (f *RegexpFile) Read(s []byte) (int, error) {
+	return f.f.Read(s)
+}
+
+func (f *RegexpFile) ReadAt(s []byte, o int64) (int, error) {
+	return f.f.ReadAt(s, o)
+}
+
+func (f *RegexpFile) Seek(o int64, w int) (int64, error) {
+	return f.f.Seek(o, w)
+}
+
+func (f *RegexpFile) Write(s []byte) (int, error) {
+	return f.f.Write(s)
+}
+
+func (f *RegexpFile) WriteAt(s []byte, o int64) (int, error) {
+	return f.f.WriteAt(s, o)
+}
+
+func (f *RegexpFile) Name() string {
+	return f.f.Name()
+}
+
+func (f *RegexpFile) Readdir(c int) (fi []os.FileInfo, err error) {
+	var rfi []os.FileInfo
+	rfi, err = f.f.Readdir(c)
+	if err != nil {
+		return nil, err
+	}
+	for _, i := range rfi {
+		if i.IsDir() || f.re.MatchString(i.Name()) {
+			fi = append(fi, i)
+		}
+	}
+	return fi, nil
+}
+
+func (f *RegexpFile) Readdirnames(c int) (n []string, err error) {
+	fi, err := f.Readdir(c)
+	if err != nil {
+		return nil, err
+	}
+	for _, s := range fi {
+		n = append(n, s.Name())
+	}
+	return n, nil
+}
+
+func (f *RegexpFile) Stat() (os.FileInfo, error) {
+	return f.f.Stat()
+}
+
+func (f *RegexpFile) Sync() error {
+	return f.f.Sync()
+}
+
+func (f *RegexpFile) Truncate(s int64) error {
+	return f.f.Truncate(s)
+}
+
+func (f *RegexpFile) WriteString(s string) (int, error) {
+	return f.f.WriteString(s)
+}

vendor/github.com/spf13/afero/symlink.go

@@ -0,0 +1,55 @@
+// Copyright © 2018 Steve Francia <spf@spf13.com>.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package afero
+
+import (
+	"errors"
+)
+
+// Symlinker is an optional interface in Afero. It is only implemented by the
+// filesystems saying so.
+// It indicates support for 3 symlink related interfaces that implement the
+// behaviors of the os methods:
+//   - Lstat
+//   - Symlink, and
+//   - Readlink
+type Symlinker interface {
+	Lstater
+	Linker
+	LinkReader
+}
+
+// Linker is an optional interface in Afero. It is only implemented by the
+// filesystems saying so.
+// It will call Symlink if the filesystem itself is, or it delegates to, the os filesystem,
+// or the filesystem otherwise supports Symlink's.
+type Linker interface {
+	SymlinkIfPossible(oldname, newname string) error
+}
+
+// ErrNoSymlink is the error that will be wrapped in an os.LinkError if a file system
+// does not support Symlink's either directly or through its delegated filesystem.
+// As expressed by support for the Linker interface.
+var ErrNoSymlink = errors.New("symlink not supported")
+
+// LinkReader is an optional interface in Afero. It is only implemented by the
+// filesystems saying so.
+type LinkReader interface {
+	ReadlinkIfPossible(name string) (string, error)
+}
+
+// ErrNoReadlink is the error that will be wrapped in an os.Path if a file system
+// does not support the readlink operation either directly or through its delegated filesystem.
+// As expressed by support for the LinkReader interface.
+var ErrNoReadlink = errors.New("readlink not supported")

vendor/github.com/spf13/afero/unionFile.go

@@ -0,0 +1,330 @@
+package afero
+
+import (
+	"io"
+	"os"
+	"path/filepath"
+	"syscall"
+)
+
+// The UnionFile implements the afero.File interface and will be returned
+// when reading a directory present at least in the overlay or opening a file
+// for writing.
+//
+// The calls to
+// Readdir() and Readdirnames() merge the file os.FileInfo / names from the
+// base and the overlay - for files present in both layers, only those
+// from the overlay will be used.
+//
+// When opening files for writing (Create() / OpenFile() with the right flags)
+// the operations will be done in both layers, starting with the overlay. A
+// successful read in the overlay will move the cursor position in the base layer
+// by the number of bytes read.
+type UnionFile struct {
+	Base   File
+	Layer  File
+	Merger DirsMerger
+	off    int
+	files  []os.FileInfo
+}
+
+func (f *UnionFile) Close() error {
+	// first close base, so we have a newer timestamp in the overlay. If we'd close
+	// the overlay first, we'd get a cacheStale the next time we access this file
+	// -> cache would be useless ;-)
+	if f.Base != nil {
+		f.Base.Close()
+	}
+	if f.Layer != nil {
+		return f.Layer.Close()
+	}
+	return BADFD
+}
+
+func (f *UnionFile) Read(s []byte) (int, error) {
+	if f.Layer != nil {
+		n, err := f.Layer.Read(s)
+		if (err == nil || err == io.EOF) && f.Base != nil {
+			// advance the file position also in the base file, the next
+			// call may be a write at this position (or a seek with SEEK_CUR)
+			if _, seekErr := f.Base.Seek(int64(n), io.SeekCurrent); seekErr != nil {
+				// only overwrite err in case the seek fails: we need to
+				// report an eventual io.EOF to the caller
+				err = seekErr
+			}
+		}
+		return n, err
+	}
+	if f.Base != nil {
+		return f.Base.Read(s)
+	}
+	return 0, BADFD
+}
+
+func (f *UnionFile) ReadAt(s []byte, o int64) (int, error) {
+	if f.Layer != nil {
+		n, err := f.Layer.ReadAt(s, o)
+		if (err == nil || err == io.EOF) && f.Base != nil {
+			_, err = f.Base.Seek(o+int64(n), io.SeekStart)
+		}
+		return n, err
+	}
+	if f.Base != nil {
+		return f.Base.ReadAt(s, o)
+	}
+	return 0, BADFD
+}
+
+func (f *UnionFile) Seek(o int64, w int) (pos int64, err error) {
+	if f.Layer != nil {
+		pos, err = f.Layer.Seek(o, w)
+		if (err == nil || err == io.EOF) && f.Base != nil {
+			_, err = f.Base.Seek(o, w)
+		}
+		return pos, err
+	}
+	if f.Base != nil {
+		return f.Base.Seek(o, w)
+	}
+	return 0, BADFD
+}
+
+func (f *UnionFile) Write(s []byte) (n int, err error) {
+	if f.Layer != nil {
+		n, err = f.Layer.Write(s)
+		if err == nil && f.Base != nil { // hmm, do we have fixed size files where a write may hit the EOF mark?
+			_, err = f.Base.Write(s)
+		}
+		return n, err
+	}
+	if f.Base != nil {
+		return f.Base.Write(s)
+	}
+	return 0, BADFD
+}
+
+func (f *UnionFile) WriteAt(s []byte, o int64) (n int, err error) {
+	if f.Layer != nil {
+		n, err = f.Layer.WriteAt(s, o)
+		if err == nil && f.Base != nil {
+			_, err = f.Base.WriteAt(s, o)
+		}
+		return n, err
+	}
+	if f.Base != nil {
+		return f.Base.WriteAt(s, o)
+	}
+	return 0, BADFD
+}
+
+func (f *UnionFile) Name() string {
+	if f.Layer != nil {
+		return f.Layer.Name()
+	}
+	return f.Base.Name()
+}
+
+// DirsMerger is how UnionFile weaves two directories together.
+// It takes the FileInfo slices from the layer and the base and returns a
+// single view.
+type DirsMerger func(lofi, bofi []os.FileInfo) ([]os.FileInfo, error)
+
+var defaultUnionMergeDirsFn = func(lofi, bofi []os.FileInfo) ([]os.FileInfo, error) {
+	files := make(map[string]os.FileInfo)
+
+	for _, fi := range lofi {
+		files[fi.Name()] = fi
+	}
+
+	for _, fi := range bofi {
+		if _, exists := files[fi.Name()]; !exists {
+			files[fi.Name()] = fi
+		}
+	}
+
+	rfi := make([]os.FileInfo, len(files))
+
+	i := 0
+	for _, fi := range files {
+		rfi[i] = fi
+		i++
+	}
+
+	return rfi, nil
+}
+
+// Readdir will weave the two directories together and
+// return a single view of the overlayed directories.
+// At the end of the directory view, the error is io.EOF if c > 0.
+func (f *UnionFile) Readdir(c int) (ofi []os.FileInfo, err error) {
+	var merge DirsMerger = f.Merger
+	if merge == nil {
+		merge = defaultUnionMergeDirsFn
+	}
+
+	if f.off == 0 {
+		var lfi []os.FileInfo
+		if f.Layer != nil {
+			lfi, err = f.Layer.Readdir(-1)
+			if err != nil {
+				return nil, err
+			}
+		}
+
+		var bfi []os.FileInfo
+		if f.Base != nil {
+			bfi, err = f.Base.Readdir(-1)
+			if err != nil {
+				return nil, err
+			}
+
+		}
+		merged, err := merge(lfi, bfi)
+		if err != nil {
+			return nil, err
+		}
+		f.files = append(f.files, merged...)
+	}
+	files := f.files[f.off:]
+
+	if c <= 0 {
+		return files, nil
+	}
+
+	if len(files) == 0 {
+		return nil, io.EOF
+	}
+
+	if c > len(files) {
+		c = len(files)
+	}
+
+	defer func() { f.off += c }()
+	return files[:c], nil
+}
+
+func (f *UnionFile) Readdirnames(c int) ([]string, error) {
+	rfi, err := f.Readdir(c)
+	if err != nil {
+		return nil, err
+	}
+	var names []string
+	for _, fi := range rfi {
+		names = append(names, fi.Name())
+	}
+	return names, nil
+}
+
+func (f *UnionFile) Stat() (os.FileInfo, error) {
+	if f.Layer != nil {
+		return f.Layer.Stat()
+	}
+	if f.Base != nil {
+		return f.Base.Stat()
+	}
+	return nil, BADFD
+}
+
+func (f *UnionFile) Sync() (err error) {
+	if f.Layer != nil {
+		err = f.Layer.Sync()
+		if err == nil && f.Base != nil {
+			err = f.Base.Sync()
+		}
+		return err
+	}
+	if f.Base != nil {
+		return f.Base.Sync()
+	}
+	return BADFD
+}
+
+func (f *UnionFile) Truncate(s int64) (err error) {
+	if f.Layer != nil {
+		err = f.Layer.Truncate(s)
+		if err == nil && f.Base != nil {
+			err = f.Base.Truncate(s)
+		}
+		return err
+	}
+	if f.Base != nil {
+		return f.Base.Truncate(s)
+	}
+	return BADFD
+}
+
+func (f *UnionFile) WriteString(s string) (n int, err error) {
+	if f.Layer != nil {
+		n, err = f.Layer.WriteString(s)
+		if err == nil && f.Base != nil {
+			_, err = f.Base.WriteString(s)
+		}
+		return n, err
+	}
+	if f.Base != nil {
+		return f.Base.WriteString(s)
+	}
+	return 0, BADFD
+}
+
+func copyFile(base Fs, layer Fs, name string, bfh File) error {
+	// First make sure the directory exists
+	exists, err := Exists(layer, filepath.Dir(name))
+	if err != nil {
+		return err
+	}
+	if !exists {
+		err = layer.MkdirAll(filepath.Dir(name), 0o777) // FIXME?
+		if err != nil {
+			return err
+		}
+	}
+
+	// Create the file on the overlay
+	lfh, err := layer.Create(name)
+	if err != nil {
+		return err
+	}
+	n, err := io.Copy(lfh, bfh)
+	if err != nil {
+		// If anything fails, clean up the file
+		layer.Remove(name)
+		lfh.Close()
+		return err
+	}
+
+	bfi, err := bfh.Stat()
+	if err != nil || bfi.Size() != n {
+		layer.Remove(name)
+		lfh.Close()
+		return syscall.EIO
+	}
+
+	err = lfh.Close()
+	if err != nil {
+		layer.Remove(name)
+		lfh.Close()
+		return err
+	}
+	return layer.Chtimes(name, bfi.ModTime(), bfi.ModTime())
+}
+
+func copyToLayer(base Fs, layer Fs, name string) error {
+	bfh, err := base.Open(name)
+	if err != nil {
+		return err
+	}
+	defer bfh.Close()
+
+	return copyFile(base, layer, name, bfh)
+}
+
+func copyFileToLayer(base Fs, layer Fs, name string, flag int, perm os.FileMode) error {
+	bfh, err := base.OpenFile(name, flag, perm)
+	if err != nil {
+		return err
+	}
+	defer bfh.Close()
+
+	return copyFile(base, layer, name, bfh)
+}

vendor/github.com/spf13/afero/util.go

@@ -0,0 +1,329 @@
+// Copyright ©2015 Steve Francia <spf@spf13.com>
+// Portions Copyright ©2015 The Hugo Authors
+// Portions Copyright 2016-present Bjørn Erik Pedersen <bjorn.erik.pedersen@gmail.com>
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package afero
+
+import (
+	"bytes"
+	"fmt"
+	"io"
+	"os"
+	"path/filepath"
+	"strings"
+	"unicode"
+
+	"golang.org/x/text/runes"
+	"golang.org/x/text/transform"
+	"golang.org/x/text/unicode/norm"
+)
+
+// Filepath separator defined by os.Separator.
+const FilePathSeparator = string(filepath.Separator)
+
+// Takes a reader and a path and writes the content
+func (a Afero) WriteReader(path string, r io.Reader) (err error) {
+	return WriteReader(a.Fs, path, r)
+}
+
+func WriteReader(fs Fs, path string, r io.Reader) (err error) {
+	dir, _ := filepath.Split(path)
+	ospath := filepath.FromSlash(dir)
+
+	if ospath != "" {
+		err = fs.MkdirAll(ospath, 0o777) // rwx, rw, r
+		if err != nil {
+			if err != os.ErrExist {
+				return err
+			}
+		}
+	}
+
+	file, err := fs.Create(path)
+	if err != nil {
+		return
+	}
+	defer file.Close()
+
+	_, err = io.Copy(file, r)
+	return
+}
+
+// Same as WriteReader but checks to see if file/directory already exists.
+func (a Afero) SafeWriteReader(path string, r io.Reader) (err error) {
+	return SafeWriteReader(a.Fs, path, r)
+}
+
+func SafeWriteReader(fs Fs, path string, r io.Reader) (err error) {
+	dir, _ := filepath.Split(path)
+	ospath := filepath.FromSlash(dir)
+
+	if ospath != "" {
+		err = fs.MkdirAll(ospath, 0o777) // rwx, rw, r
+		if err != nil {
+			return
+		}
+	}
+
+	exists, err := Exists(fs, path)
+	if err != nil {
+		return
+	}
+	if exists {
+		return fmt.Errorf("%v already exists", path)
+	}
+
+	file, err := fs.Create(path)
+	if err != nil {
+		return
+	}
+	defer file.Close()
+
+	_, err = io.Copy(file, r)
+	return
+}
+
+func (a Afero) GetTempDir(subPath string) string {
+	return GetTempDir(a.Fs, subPath)
+}
+
+// GetTempDir returns the default temp directory with trailing slash
+// if subPath is not empty then it will be created recursively with mode 777 rwx rwx rwx
+func GetTempDir(fs Fs, subPath string) string {
+	addSlash := func(p string) string {
+		if FilePathSeparator != p[len(p)-1:] {
+			p = p + FilePathSeparator
+		}
+		return p
+	}
+	dir := addSlash(os.TempDir())
+
+	if subPath != "" {
+		// preserve windows backslash :-(
+		if FilePathSeparator == "\\" {
+			subPath = strings.Replace(subPath, "\\", "____", -1)
+		}
+		dir = dir + UnicodeSanitize((subPath))
+		if FilePathSeparator == "\\" {
+			dir = strings.Replace(dir, "____", "\\", -1)
+		}
+
+		if exists, _ := Exists(fs, dir); exists {
+			return addSlash(dir)
+		}
+
+		err := fs.MkdirAll(dir, 0o777)
+		if err != nil {
+			panic(err)
+		}
+		dir = addSlash(dir)
+	}
+	return dir
+}
+
+// Rewrite string to remove non-standard path characters
+func UnicodeSanitize(s string) string {
+	source := []rune(s)
+	target := make([]rune, 0, len(source))
+
+	for _, r := range source {
+		if unicode.IsLetter(r) ||
+			unicode.IsDigit(r) ||
+			unicode.IsMark(r) ||
+			r == '.' ||
+			r == '/' ||
+			r == '\\' ||
+			r == '_' ||
+			r == '-' ||
+			r == '%' ||
+			r == ' ' ||
+			r == '#' {
+			target = append(target, r)
+		}
+	}
+
+	return string(target)
+}
+
+// Transform characters with accents into plain forms.
+func NeuterAccents(s string) string {
+	t := transform.Chain(norm.NFD, runes.Remove(runes.In(unicode.Mn)), norm.NFC)
+	result, _, _ := transform.String(t, string(s))
+
+	return result
+}
+
+func (a Afero) FileContainsBytes(filename string, subslice []byte) (bool, error) {
+	return FileContainsBytes(a.Fs, filename, subslice)
+}
+
+// Check if a file contains a specified byte slice.
+func FileContainsBytes(fs Fs, filename string, subslice []byte) (bool, error) {
+	f, err := fs.Open(filename)
+	if err != nil {
+		return false, err
+	}
+	defer f.Close()
+
+	return readerContainsAny(f, subslice), nil
+}
+
+func (a Afero) FileContainsAnyBytes(filename string, subslices [][]byte) (bool, error) {
+	return FileContainsAnyBytes(a.Fs, filename, subslices)
+}
+
+// Check if a file contains any of the specified byte slices.
+func FileContainsAnyBytes(fs Fs, filename string, subslices [][]byte) (bool, error) {
+	f, err := fs.Open(filename)
+	if err != nil {
+		return false, err
+	}
+	defer f.Close()
+
+	return readerContainsAny(f, subslices...), nil
+}
+
+// readerContains reports whether any of the subslices is within r.
+func readerContainsAny(r io.Reader, subslices ...[]byte) bool {
+	if r == nil || len(subslices) == 0 {
+		return false
+	}
+
+	largestSlice := 0
+
+	for _, sl := range subslices {
+		if len(sl) > largestSlice {
+			largestSlice = len(sl)
+		}
+	}
+
+	if largestSlice == 0 {
+		return false
+	}
+
+	bufflen := largestSlice * 4
+	halflen := bufflen / 2
+	buff := make([]byte, bufflen)
+	var err error
+	var n, i int
+
+	for {
+		i++
+		if i == 1 {
+			n, err = io.ReadAtLeast(r, buff[:halflen], halflen)
+		} else {
+			if i != 2 {
+				// shift left to catch overlapping matches
+				copy(buff[:], buff[halflen:])
+			}
+			n, err = io.ReadAtLeast(r, buff[halflen:], halflen)
+		}
+
+		if n > 0 {
+			for _, sl := range subslices {
+				if bytes.Contains(buff, sl) {
+					return true
+				}
+			}
+		}
+
+		if err != nil {
+			break
+		}
+	}
+	return false
+}
+
+func (a Afero) DirExists(path string) (bool, error) {
+	return DirExists(a.Fs, path)
+}
+
+// DirExists checks if a path exists and is a directory.
+func DirExists(fs Fs, path string) (bool, error) {
+	fi, err := fs.Stat(path)
+	if err == nil && fi.IsDir() {
+		return true, nil
+	}
+	if os.IsNotExist(err) {
+		return false, nil
+	}
+	return false, err
+}
+
+func (a Afero) IsDir(path string) (bool, error) {
+	return IsDir(a.Fs, path)
+}
+
+// IsDir checks if a given path is a directory.
+func IsDir(fs Fs, path string) (bool, error) {
+	fi, err := fs.Stat(path)
+	if err != nil {
+		return false, err
+	}
+	return fi.IsDir(), nil
+}
+
+func (a Afero) IsEmpty(path string) (bool, error) {
+	return IsEmpty(a.Fs, path)
+}
+
+// IsEmpty checks if a given file or directory is empty.
+func IsEmpty(fs Fs, path string) (bool, error) {
+	if b, _ := Exists(fs, path); !b {
+		return false, fmt.Errorf("%q path does not exist", path)
+	}
+	fi, err := fs.Stat(path)
+	if err != nil {
+		return false, err
+	}
+	if fi.IsDir() {
+		f, err := fs.Open(path)
+		if err != nil {
+			return false, err
+		}
+		defer f.Close()
+		list, err := f.Readdir(-1)
+		if err != nil {
+			return false, err
+		}
+		return len(list) == 0, nil
+	}
+	return fi.Size() == 0, nil
+}
+
+func (a Afero) Exists(path string) (bool, error) {
+	return Exists(a.Fs, path)
+}
+
+// Check if a file or directory exists.
+func Exists(fs Fs, path string) (bool, error) {
+	_, err := fs.Stat(path)
+	if err == nil {
+		return true, nil
+	}
+	if os.IsNotExist(err) {
+		return false, nil
+	}
+	return false, err
+}
+
+func FullBaseFsPath(basePathFs *BasePathFs, relativePath string) string {
+	combinedPath := filepath.Join(basePathFs.path, relativePath)
+	if parent, ok := basePathFs.source.(*BasePathFs); ok {
+		return FullBaseFsPath(parent, combinedPath)
+	}
+
+	return combinedPath
+}