Filesystem: Changes API

This commit is contained in:
Andrea Luzzardi 2013-01-25 11:05:11 -08:00
parent 4fc390ee39
commit 09502e4faa
2 changed files with 197 additions and 4 deletions

View File

@ -4,6 +4,8 @@ import (
"errors"
"fmt"
"os"
"path/filepath"
"strings"
"syscall"
)
@ -65,6 +67,91 @@ func (fs *Filesystem) IsMounted() bool {
return false
}
type ChangeType int
const (
ChangeModify = iota
ChangeAdd
ChangeDelete
)
type Change struct {
Path string
Kind ChangeType
}
func (fs *Filesystem) Changes() ([]Change, error) {
var changes []Change
err := filepath.Walk(fs.RWPath, func(path string, f os.FileInfo, err error) error {
if err != nil {
return err
}
// Rebase path
path, err = filepath.Rel(fs.RWPath, path)
if err != nil {
return err
}
path = filepath.Join("/", path)
// Skip root
if path == "/" {
return nil
}
// Skip AUFS metadata
if matched, err := filepath.Match("/.wh..wh.*", path); err != nil || matched {
return err
}
change := Change{
Path: path,
}
// Find out what kind of modification happened
file := filepath.Base(path)
// If there is a whiteout, then the file was removed
if strings.HasPrefix(file, ".wh.") {
originalFile := strings.TrimLeft(file, ".wh.")
change.Path = filepath.Join(filepath.Dir(path), originalFile)
change.Kind = ChangeDelete
} else {
// Otherwise, the file was added
change.Kind = ChangeAdd
// ...Unless it already existed in a top layer, in which case, it's a modification
for _, layer := range fs.Layers {
stat, err := os.Stat(filepath.Join(layer, path))
if err != nil && !os.IsNotExist(err) {
return err
}
if err == nil {
// The file existed in the top layer, so that's a modification
// However, if it's a directory, maybe it wasn't actually modified.
// If you modify /foo/bar/baz, then /foo will be part of the changed files only because it's the parent of bar
if stat.IsDir() && f.IsDir() {
if f.Size() == stat.Size() && f.Mode() == stat.Mode() && f.ModTime() == stat.ModTime() {
// Both directories are the same, don't record the change
return nil
}
}
change.Kind = ChangeModify
break
}
}
}
// Record change
changes = append(changes, change)
return nil
})
if err != nil {
return nil, err
}
return changes, nil
}
func newFilesystem(rootfs string, rwpath string, layers []string) *Filesystem {
return &Filesystem{
RootFS: rootfs,

View File

@ -8,12 +8,12 @@ import (
"testing"
)
func newTestFilesystem(t *testing.T, layers []string) (rootfs string, rwpath string, fs *Filesystem) {
func newTestFilesystem(t *testing.T, layers []string) (rootfs string, fs *Filesystem) {
rootfs, err := ioutil.TempDir("", "docker-test-root")
if err != nil {
t.Fatal(err)
}
rwpath, err = ioutil.TempDir("", "docker-test-rw")
rwpath, err := ioutil.TempDir("", "docker-test-rw")
if err != nil {
t.Fatal(err)
}
@ -22,7 +22,7 @@ func newTestFilesystem(t *testing.T, layers []string) (rootfs string, rwpath str
}
func TestFilesystem(t *testing.T) {
_, _, filesystem := newTestFilesystem(t, []string{"/var/lib/docker/images/ubuntu"})
_, filesystem := newTestFilesystem(t, []string{"/var/lib/docker/images/ubuntu"})
if err := filesystem.Umount(); err == nil {
t.Errorf("Umount succeeded even though the filesystem was not mounted")
}
@ -56,7 +56,7 @@ func TestFilesystemMultiLayer(t *testing.T) {
}
// Create the layered filesystem and add our fake layer on top
rootfs, _, filesystem := newTestFilesystem(t, []string{"/var/lib/docker/images/ubuntu", fakeLayer})
rootfs, filesystem := newTestFilesystem(t, []string{"/var/lib/docker/images/ubuntu", fakeLayer})
// Mount it
if err := filesystem.Mount(); err != nil {
@ -80,3 +80,109 @@ func TestFilesystemMultiLayer(t *testing.T) {
t.Error(string(fsdata))
}
}
func TestChanges(t *testing.T) {
rootfs, filesystem := newTestFilesystem(t, []string{"/var/lib/docker/images/ubuntu"})
// Mount it
if err := filesystem.Mount(); err != nil {
t.Fatal(err)
}
defer filesystem.Umount()
var changes []Change
var err error
// Test without changes
changes, err = filesystem.Changes()
if err != nil {
t.Fatal(err)
}
if len(changes) != 0 {
t.Errorf("Unexpected changes :%v", changes)
}
// Test simple change
file, err := os.Create(path.Join(rootfs, "test_change"))
if err != nil {
t.Fatal(err)
}
file.Close()
changes, err = filesystem.Changes()
if err != nil {
t.Fatal(err)
}
if len(changes) != 1 {
t.Errorf("Unexpected changes :%v", changes)
}
if changes[0].Path != "/test_change" || changes[0].Kind != ChangeAdd {
t.Errorf("Unexpected changes :%v", changes)
}
// Test subdirectory change
if err := os.Mkdir(path.Join(rootfs, "sub_change"), 0700); err != nil {
t.Fatal(err)
}
file, err = os.Create(path.Join(rootfs, "sub_change", "test"))
if err != nil {
t.Fatal(err)
}
file.Close()
changes, err = filesystem.Changes()
if err != nil {
t.Fatal(err)
}
if len(changes) != 3 {
t.Errorf("Unexpected changes: %v", changes)
}
if changes[0].Path != "/sub_change" || changes[0].Kind != ChangeAdd || changes[1].Path != "/sub_change/test" || changes[1].Kind != ChangeAdd {
t.Errorf("Unexpected changes: %v", changes)
}
// Test permission change
if err := os.Chmod(path.Join(rootfs, "root"), 0000); err != nil {
t.Fatal(err)
}
changes, err = filesystem.Changes()
if err != nil {
t.Fatal(err)
}
if len(changes) != 4 {
t.Errorf("Unexpected changes: %v", changes)
}
if changes[0].Path != "/root" || changes[0].Kind != ChangeModify {
t.Errorf("Unexpected changes: %v", changes)
}
// Test removal
if err := os.Remove(path.Join(rootfs, "etc", "passwd")); err != nil {
t.Fatal(err)
}
changes, err = filesystem.Changes()
if err != nil {
t.Fatal(err)
}
if len(changes) != 6 {
t.Errorf("Unexpected changes: %v", changes)
}
if changes[0].Path != "/etc" || changes[0].Kind != ChangeModify || changes[1].Path != "/etc/passwd" || changes[1].Kind != ChangeDelete {
t.Errorf("Unexpected changes: %v", changes)
}
// Test sub-directory removal
if err := os.Remove(path.Join(rootfs, "usr", "bin", "sudo")); err != nil {
t.Fatal(err)
}
changes, err = filesystem.Changes()
if err != nil {
t.Fatal(err)
}
if len(changes) != 8 {
t.Errorf("Unexpected changes: %v", changes)
}
if changes[6].Path != "/usr/bin" || changes[6].Kind != ChangeModify || changes[7].Path != "/usr/bin/sudo" || changes[7].Kind != ChangeDelete {
t.Errorf("Unexpected changes: %v", changes)
}
}