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package remotecontext // import "github.com/docker/docker/builder/remotecontext"
import (
"io"
"os"
"path/filepath"
"github.com/docker/docker/builder"
"github.com/docker/docker/pkg/archive"
"github.com/docker/docker/pkg/chrootarchive"
"github.com/docker/docker/pkg/containerfs"
"github.com/docker/docker/pkg/longpath"
"github.com/docker/docker/pkg/tarsum"
"github.com/pkg/errors"
)
type archiveContext struct {
root string
sums tarsum.FileInfoSums
}
func (c *archiveContext) Close() error {
return os.RemoveAll(c.root)
}
func convertPathError(err error, cleanpath string) error {
if err, ok := err.(*os.PathError); ok {
err.Path = cleanpath
return err
}
return err
}
type modifiableContext interface {
builder.Source
// Remove deletes the entry specified by `path`.
// It is usual for directory entries to delete all its subentries.
Remove(path string) error
}
// FromArchive returns a build source from a tar stream.
//
// It extracts the tar stream to a temporary folder that is deleted as soon as
// the Context is closed.
// As the extraction happens, a tarsum is calculated for every file, and the set of
// all those sums then becomes the source of truth for all operations on this Context.
//
// Closing tarStream has to be done by the caller.
func FromArchive(tarStream io.Reader) (builder.Source, error) {
root, err := longpath.MkdirTemp("", "docker-builder")
if err != nil {
return nil, err
}
// Assume local file system. Since it's coming from a tar file.
tsc := &archiveContext{root: root}
// Make sure we clean-up upon error. In the happy case the caller
// is expected to manage the clean-up
defer func() {
if err != nil {
tsc.Close()
}
}()
decompressedStream, err := archive.DecompressStream(tarStream)
if err != nil {
return nil, err
}
sum, err := tarsum.NewTarSum(decompressedStream, true, tarsum.Version1)
if err != nil {
return nil, err
}
err = chrootarchive.Untar(sum, root, nil)
if err != nil {
return nil, err
}
tsc.sums = sum.GetSums()
return tsc, nil
}
func (c *archiveContext) Root() string {
return c.root
}
func (c *archiveContext) Remove(path string) error {
_, fullpath, err := normalize(path, c.root)
if err != nil {
return err
}
return os.RemoveAll(fullpath)
}
func (c *archiveContext) Hash(path string) (string, error) {
cleanpath, fullpath, err := normalize(path, c.root)
if err != nil {
return "", err
}
rel, err := filepath.Rel(c.root, fullpath)
if err != nil {
return "", convertPathError(err, cleanpath)
}
// Use the checksum of the followed path(not the possible symlink) because
// this is the file that is actually copied.
if tsInfo := c.sums.GetFile(filepath.ToSlash(rel)); tsInfo != nil {
return tsInfo.Sum(), nil
}
// We set sum to path by default for the case where GetFile returns nil.
// The usual case is if relative path is empty.
return path, nil // backwards compat TODO: see if really needed
}
func normalize(path string, root string) (cleanPath, fullPath string, err error) {
cleanPath = filepath.Clean(string(filepath.Separator) + path)[1:]
fullPath, err = containerfs.ResolveScopedPath(root, path)
if err != nil {
return "", "", errors.Wrapf(err, "forbidden path outside the build context: %s (%s)", path, cleanPath)
}
return
}
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