package remotecontext // import "github.com/docker/docker/builder/remotecontext" import ( "bufio" "fmt" "io" "os" "runtime" "strings" "github.com/containerd/continuity/driver" "github.com/docker/docker/api/types/backend" "github.com/docker/docker/builder" "github.com/docker/docker/builder/dockerignore" "github.com/docker/docker/pkg/fileutils" "github.com/docker/docker/pkg/urlutil" "github.com/moby/buildkit/frontend/dockerfile/parser" "github.com/pkg/errors" "github.com/sirupsen/logrus" ) // ClientSessionRemote is identifier for client-session context transport const ClientSessionRemote = "client-session" // Detect returns a context and dockerfile from remote location or local // archive. func Detect(config backend.BuildConfig) (remote builder.Source, dockerfile *parser.Result, err error) { remoteURL := config.Options.RemoteContext dockerfilePath := config.Options.Dockerfile switch { case remoteURL == "": remote, dockerfile, err = newArchiveRemote(config.Source, dockerfilePath) case remoteURL == ClientSessionRemote: res, err := parser.Parse(config.Source) if err != nil { return nil, nil, err } return nil, res, nil case urlutil.IsGitURL(remoteURL): remote, dockerfile, err = newGitRemote(remoteURL, dockerfilePath) case urlutil.IsURL(remoteURL): remote, dockerfile, err = newURLRemote(remoteURL, dockerfilePath, config.ProgressWriter.ProgressReaderFunc) default: err = fmt.Errorf("remoteURL (%s) could not be recognized as URL", remoteURL) } return } func newArchiveRemote(rc io.ReadCloser, dockerfilePath string) (builder.Source, *parser.Result, error) { defer rc.Close() c, err := FromArchive(rc) if err != nil { return nil, nil, err } return withDockerfileFromContext(c.(modifiableContext), dockerfilePath) } func withDockerfileFromContext(c modifiableContext, dockerfilePath string) (builder.Source, *parser.Result, error) { df, err := openAt(c, dockerfilePath) if err != nil { if os.IsNotExist(err) { if dockerfilePath == builder.DefaultDockerfileName { lowercase := strings.ToLower(dockerfilePath) if _, err := StatAt(c, lowercase); err == nil { return withDockerfileFromContext(c, lowercase) } } return nil, nil, errors.Errorf("Cannot locate specified Dockerfile: %s", dockerfilePath) // backwards compatible error } c.Close() return nil, nil, err } res, err := readAndParseDockerfile(dockerfilePath, df) if err != nil { return nil, nil, err } df.Close() if err := removeDockerfile(c, dockerfilePath); err != nil { c.Close() return nil, nil, err } return c, res, nil } func newGitRemote(gitURL string, dockerfilePath string) (builder.Source, *parser.Result, error) { c, err := MakeGitContext(gitURL) // TODO: change this to NewLazySource if err != nil { return nil, nil, err } return withDockerfileFromContext(c.(modifiableContext), dockerfilePath) } func newURLRemote(url string, dockerfilePath string, progressReader func(in io.ReadCloser) io.ReadCloser) (builder.Source, *parser.Result, error) { contentType, content, err := downloadRemote(url) if err != nil { return nil, nil, err } defer content.Close() switch contentType { case mimeTypes.TextPlain: res, err := parser.Parse(progressReader(content)) return nil, res, err default: source, err := FromArchive(progressReader(content)) if err != nil { return nil, nil, err } return withDockerfileFromContext(source.(modifiableContext), dockerfilePath) } } func removeDockerfile(c modifiableContext, filesToRemove ...string) error { f, err := openAt(c, ".dockerignore") // Note that a missing .dockerignore file isn't treated as an error switch { case os.IsNotExist(err): return nil case err != nil: return err } excludes, err := dockerignore.ReadAll(f) if err != nil { f.Close() return err } f.Close() filesToRemove = append([]string{".dockerignore"}, filesToRemove...) for _, fileToRemove := range filesToRemove { if rm, _ := fileutils.Matches(fileToRemove, excludes); rm { if err := c.Remove(fileToRemove); err != nil { logrus.Errorf("failed to remove %s: %v", fileToRemove, err) } } } return nil } func readAndParseDockerfile(name string, rc io.Reader) (*parser.Result, error) { br := bufio.NewReader(rc) if _, err := br.Peek(1); err != nil { if err == io.EOF { return nil, errors.Errorf("the Dockerfile (%s) cannot be empty", name) } return nil, errors.Wrap(err, "unexpected error reading Dockerfile") } return parser.Parse(br) } func openAt(remote builder.Source, path string) (driver.File, error) { fullPath, err := FullPath(remote, path) if err != nil { return nil, err } return remote.Root().Open(fullPath) } // StatAt is a helper for calling Stat on a path from a source func StatAt(remote builder.Source, path string) (os.FileInfo, error) { fullPath, err := FullPath(remote, path) if err != nil { return nil, err } return remote.Root().Stat(fullPath) } // FullPath is a helper for getting a full path for a path from a source func FullPath(remote builder.Source, path string) (string, error) { fullPath, err := remote.Root().ResolveScopedPath(path, true) if err != nil { if runtime.GOOS == "windows" { return "", fmt.Errorf("failed to resolve scoped path %s (%s): %s. Possible cause is a forbidden path outside the build context", path, fullPath, err) } return "", fmt.Errorf("Forbidden path outside the build context: %s (%s)", path, fullPath) // backwards compat with old error } return fullPath, nil }