test: add basic integration tests

Signed-off-by: Justin Chadwell <me@jedevc.com>

vendor/github.com/containerd/continuity/fs/fstest/file.go

@@ -0,0 +1,184 @@
+/*
+   Copyright The containerd Authors.
+
+   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 fstest
+
+import (
+	"bytes"
+	"io"
+	"math/rand"
+	"os"
+	"path/filepath"
+	"syscall"
+	"time"
+)
+
+// Applier applies single file changes
+type Applier interface {
+	Apply(root string) error
+}
+
+type applyFn func(root string) error
+
+func (a applyFn) Apply(root string) error {
+	return a(root)
+}
+
+// CreateFile returns a file applier which creates a file as the
+// provided name with the given content and permission.
+func CreateFile(name string, content []byte, perm os.FileMode) Applier {
+	f := func() io.Reader {
+		return bytes.NewReader(content)
+	}
+	return writeFileStream(name, f, perm)
+}
+
+// CreateRandomFile returns a file applier which creates a file with random
+// content of the given size using the given seed and permission.
+func CreateRandomFile(name string, seed, size int64, perm os.FileMode) Applier {
+	f := func() io.Reader {
+		return io.LimitReader(rand.New(rand.NewSource(seed)), size)
+	}
+	return writeFileStream(name, f, perm)
+}
+
+// writeFileStream returns a file applier which creates a file as the
+// provided name with the given content from the provided i/o stream and permission.
+func writeFileStream(name string, stream func() io.Reader, perm os.FileMode) Applier {
+	return applyFn(func(root string) (retErr error) {
+		fullPath := filepath.Join(root, name)
+		f, err := os.OpenFile(fullPath, os.O_WRONLY|os.O_CREATE|os.O_TRUNC, perm)
+		if err != nil {
+			return err
+		}
+		defer func() {
+			err := f.Close()
+			if err != nil && retErr == nil {
+				retErr = err
+			}
+		}()
+		_, err = io.Copy(f, stream())
+		if err != nil {
+			return err
+		}
+		return os.Chmod(fullPath, perm)
+	})
+}
+
+// Remove returns a file applier which removes the provided file name
+func Remove(name string) Applier {
+	return applyFn(func(root string) error {
+		return os.Remove(filepath.Join(root, name))
+	})
+}
+
+// RemoveAll returns a file applier which removes the provided file name
+// as in os.RemoveAll
+func RemoveAll(name string) Applier {
+	return applyFn(func(root string) error {
+		return os.RemoveAll(filepath.Join(root, name))
+	})
+}
+
+// CreateDir returns a file applier to create the directory with
+// the provided name and permission
+func CreateDir(name string, perm os.FileMode) Applier {
+	return applyFn(func(root string) error {
+		fullPath := filepath.Join(root, name)
+		if err := os.MkdirAll(fullPath, perm); err != nil {
+			return err
+		}
+		return os.Chmod(fullPath, perm)
+	})
+}
+
+// Rename returns a file applier which renames a file
+func Rename(old, new string) Applier {
+	return applyFn(func(root string) error {
+		return os.Rename(filepath.Join(root, old), filepath.Join(root, new))
+	})
+}
+
+// Chown returns a file applier which changes the ownership of a file
+func Chown(name string, uid, gid int) Applier {
+	return applyFn(func(root string) error {
+		return os.Chown(filepath.Join(root, name), uid, gid)
+	})
+}
+
+// Chtimes changes access and mod time of file.
+// Use Lchtimes for symbolic links.
+func Chtimes(name string, atime, mtime time.Time) Applier {
+	return applyFn(func(root string) error {
+		return os.Chtimes(filepath.Join(root, name), atime, mtime)
+	})
+}
+
+// Chmod returns a file applier which changes the file permission
+func Chmod(name string, perm os.FileMode) Applier {
+	return applyFn(func(root string) error {
+		return os.Chmod(filepath.Join(root, name), perm)
+	})
+}
+
+// Symlink returns a file applier which creates a symbolic link
+func Symlink(oldname, newname string) Applier {
+	return applyFn(func(root string) error {
+		return os.Symlink(oldname, filepath.Join(root, newname))
+	})
+}
+
+// Link returns a file applier which creates a hard link
+func Link(oldname, newname string) Applier {
+	return applyFn(func(root string) error {
+		return os.Link(filepath.Join(root, oldname), filepath.Join(root, newname))
+	})
+}
+
+// TODO: Make platform specific, windows applier is always no-op
+//func Mknod(name string, mode int32, dev int) Applier {
+//	return func(root string) error {
+//		return return syscall.Mknod(path, mode, dev)
+//	}
+//}
+
+func CreateSocket(name string, perm os.FileMode) Applier {
+	return applyFn(func(root string) error {
+		fullPath := filepath.Join(root, name)
+		fd, err := syscall.Socket(syscall.AF_UNIX, syscall.SOCK_STREAM, 0)
+		if err != nil {
+			return err
+		}
+		defer syscall.Close(fd)
+		sa := &syscall.SockaddrUnix{Name: fullPath}
+		if err := syscall.Bind(fd, sa); err != nil {
+			return err
+		}
+		return os.Chmod(fullPath, perm)
+	})
+}
+
+// Apply returns a new applier from the given appliers
+func Apply(appliers ...Applier) Applier {
+	return applyFn(func(root string) error {
+		for _, a := range appliers {
+			if err := a.Apply(root); err != nil {
+				return err
+			}
+		}
+		return nil
+	})
+}