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moby--moby/builder/remotecontext/lazycontext.go
Tonis Tiigi 684633f734 Fix relative path on windows for uuid paths
Signed-off-by: Tonis Tiigi <tonistiigi@gmail.com>
2017-03-23 15:12:19 -07:00

166 lines
4 KiB
Go

package remotecontext
import (
"encoding/hex"
"io"
"os"
"path/filepath"
"runtime"
"strings"
"github.com/docker/docker/builder"
"github.com/docker/docker/pkg/pools"
"github.com/docker/docker/pkg/symlink"
"github.com/pkg/errors"
)
// NewLazyContext creates a new LazyContext. LazyContext defines a hashed build
// context based on a root directory. Individual files are hashed first time
// they are asked. It is not safe to call methods of LazyContext concurrently.
func NewLazyContext(root string) (builder.Context, error) {
return &lazyContext{
root: root,
sums: make(map[string]string),
}, nil
}
type lazyContext struct {
root string
sums map[string]string
}
func (c *lazyContext) Close() error {
return nil
}
func (c *lazyContext) Open(path string) (io.ReadCloser, error) {
cleanPath, fullPath, err := c.normalize(path)
if err != nil {
return nil, err
}
r, err := os.Open(fullPath)
if err != nil {
return nil, errors.WithStack(convertPathError(err, cleanPath))
}
return r, nil
}
func (c *lazyContext) Stat(path string) (string, builder.FileInfo, error) {
// TODO: although stat returns builder.FileInfo it builder.Context actually requires Hashed
cleanPath, fullPath, err := c.normalize(path)
if err != nil {
return "", nil, err
}
st, err := os.Lstat(fullPath)
if err != nil {
return "", nil, errors.WithStack(convertPathError(err, cleanPath))
}
relPath, err := rel(c.root, fullPath)
if err != nil {
return "", nil, errors.WithStack(convertPathError(err, cleanPath))
}
sum, ok := c.sums[relPath]
if !ok {
sum, err = c.prepareHash(relPath, st)
if err != nil {
return "", nil, err
}
}
fi := &builder.HashedFileInfo{
builder.PathFileInfo{st, fullPath, filepath.Base(cleanPath)},
sum,
}
return relPath, fi, nil
}
func (c *lazyContext) Walk(root string, walkFn builder.WalkFunc) error {
_, fullPath, err := c.normalize(root)
if err != nil {
return err
}
return filepath.Walk(fullPath, func(fullPath string, fi os.FileInfo, err error) error {
relPath, err := rel(c.root, fullPath)
if err != nil {
return errors.WithStack(err)
}
if relPath == "." {
return nil
}
sum, ok := c.sums[relPath]
if !ok {
sum, err = c.prepareHash(relPath, fi)
if err != nil {
return err
}
}
hfi := &builder.HashedFileInfo{
builder.PathFileInfo{FileInfo: fi, FilePath: fullPath},
sum,
}
if err := walkFn(relPath, hfi, nil); err != nil {
return err
}
return nil
})
}
func (c *lazyContext) prepareHash(relPath string, fi os.FileInfo) (string, error) {
p := filepath.Join(c.root, relPath)
h, err := NewFileHash(p, relPath, fi)
if err != nil {
return "", errors.Wrapf(err, "failed to create hash for %s", relPath)
}
if fi.Mode().IsRegular() && fi.Size() > 0 {
f, err := os.Open(p)
if err != nil {
return "", errors.Wrapf(err, "failed to open %s", relPath)
}
defer f.Close()
if _, err := pools.Copy(h, f); err != nil {
return "", errors.Wrapf(err, "failed to copy file data for %s", relPath)
}
}
sum := hex.EncodeToString(h.Sum(nil))
c.sums[relPath] = sum
return sum, nil
}
func (c *lazyContext) normalize(path string) (cleanPath, fullPath string, err error) {
// todo: combine these helpers with tarsum after they are moved to same package
cleanPath = filepath.Clean(string(os.PathSeparator) + path)[1:]
fullPath, err = symlink.FollowSymlinkInScope(filepath.Join(c.root, path), c.root)
if err != nil {
return "", "", errors.Wrapf(err, "forbidden path outside the build context: %s (%s)", path, fullPath)
}
return
}
func convertPathError(err error, cleanpath string) error {
if err, ok := err.(*os.PathError); ok {
err.Path = cleanpath
return err
}
return err
}
func rel(basepath, targpath string) (string, error) {
// filepath.Rel can't handle UUID paths in windows
if runtime.GOOS == "windows" {
pfx := basepath + `\`
if strings.HasPrefix(targpath, pfx) {
p := strings.TrimPrefix(targpath, pfx)
if p == "" {
p = "."
}
return p, nil
}
}
return filepath.Rel(basepath, targpath)
}