package registry // import "github.com/docker/docker/registry" import ( "bytes" "crypto/sha256" // this is required for some certificates _ "crypto/sha512" "encoding/hex" "encoding/json" "fmt" "io" "io/ioutil" "net/http" "net/http/cookiejar" "net/url" "strconv" "strings" "sync" "github.com/docker/distribution/reference" "github.com/docker/distribution/registry/api/errcode" "github.com/docker/docker/api/types" registrytypes "github.com/docker/docker/api/types/registry" "github.com/docker/docker/errdefs" "github.com/docker/docker/pkg/ioutils" "github.com/docker/docker/pkg/jsonmessage" "github.com/docker/docker/pkg/stringid" "github.com/docker/docker/pkg/tarsum" "github.com/docker/docker/registry/resumable" "github.com/pkg/errors" "github.com/sirupsen/logrus" ) var ( // ErrRepoNotFound is returned if the repository didn't exist on the // remote side ErrRepoNotFound notFoundError = "Repository not found" ) // A Session is used to communicate with a V1 registry type Session struct { indexEndpoint *V1Endpoint client *http.Client // TODO(tiborvass): remove authConfig authConfig *types.AuthConfig id string } type authTransport struct { http.RoundTripper *types.AuthConfig alwaysSetBasicAuth bool token []string mu sync.Mutex // guards modReq modReq map[*http.Request]*http.Request // original -> modified } // AuthTransport handles the auth layer when communicating with a v1 registry (private or official) // // For private v1 registries, set alwaysSetBasicAuth to true. // // For the official v1 registry, if there isn't already an Authorization header in the request, // but there is an X-Docker-Token header set to true, then Basic Auth will be used to set the Authorization header. // After sending the request with the provided base http.RoundTripper, if an X-Docker-Token header, representing // a token, is present in the response, then it gets cached and sent in the Authorization header of all subsequent // requests. // // If the server sends a token without the client having requested it, it is ignored. // // This RoundTripper also has a CancelRequest method important for correct timeout handling. func AuthTransport(base http.RoundTripper, authConfig *types.AuthConfig, alwaysSetBasicAuth bool) http.RoundTripper { if base == nil { base = http.DefaultTransport } return &authTransport{ RoundTripper: base, AuthConfig: authConfig, alwaysSetBasicAuth: alwaysSetBasicAuth, modReq: make(map[*http.Request]*http.Request), } } // cloneRequest returns a clone of the provided *http.Request. // The clone is a shallow copy of the struct and its Header map. func cloneRequest(r *http.Request) *http.Request { // shallow copy of the struct r2 := new(http.Request) *r2 = *r // deep copy of the Header r2.Header = make(http.Header, len(r.Header)) for k, s := range r.Header { r2.Header[k] = append([]string(nil), s...) } return r2 } // RoundTrip changes an HTTP request's headers to add the necessary // authentication-related headers func (tr *authTransport) RoundTrip(orig *http.Request) (*http.Response, error) { // Authorization should not be set on 302 redirect for untrusted locations. // This logic mirrors the behavior in addRequiredHeadersToRedirectedRequests. // As the authorization logic is currently implemented in RoundTrip, // a 302 redirect is detected by looking at the Referrer header as go http package adds said header. // This is safe as Docker doesn't set Referrer in other scenarios. if orig.Header.Get("Referer") != "" && !trustedLocation(orig) { return tr.RoundTripper.RoundTrip(orig) } req := cloneRequest(orig) tr.mu.Lock() tr.modReq[orig] = req tr.mu.Unlock() if tr.alwaysSetBasicAuth { if tr.AuthConfig == nil { return nil, errors.New("unexpected error: empty auth config") } req.SetBasicAuth(tr.Username, tr.Password) return tr.RoundTripper.RoundTrip(req) } // Don't override if req.Header.Get("Authorization") == "" { if req.Header.Get("X-Docker-Token") == "true" && tr.AuthConfig != nil && len(tr.Username) > 0 { req.SetBasicAuth(tr.Username, tr.Password) } else if len(tr.token) > 0 { req.Header.Set("Authorization", "Token "+strings.Join(tr.token, ",")) } } resp, err := tr.RoundTripper.RoundTrip(req) if err != nil { tr.mu.Lock() delete(tr.modReq, orig) tr.mu.Unlock() return nil, err } if len(resp.Header["X-Docker-Token"]) > 0 { tr.token = resp.Header["X-Docker-Token"] } resp.Body = &ioutils.OnEOFReader{ Rc: resp.Body, Fn: func() { tr.mu.Lock() delete(tr.modReq, orig) tr.mu.Unlock() }, } return resp, nil } // CancelRequest cancels an in-flight request by closing its connection. func (tr *authTransport) CancelRequest(req *http.Request) { type canceler interface { CancelRequest(*http.Request) } if cr, ok := tr.RoundTripper.(canceler); ok { tr.mu.Lock() modReq := tr.modReq[req] delete(tr.modReq, req) tr.mu.Unlock() cr.CancelRequest(modReq) } } func authorizeClient(client *http.Client, authConfig *types.AuthConfig, endpoint *V1Endpoint) error { var alwaysSetBasicAuth bool // If we're working with a standalone private registry over HTTPS, send Basic Auth headers // alongside all our requests. if endpoint.String() != IndexServer && endpoint.URL.Scheme == "https" { info, err := endpoint.Ping() if err != nil { return err } if info.Standalone && authConfig != nil { logrus.Debugf("Endpoint %s is eligible for private registry. Enabling decorator.", endpoint.String()) alwaysSetBasicAuth = true } } // Annotate the transport unconditionally so that v2 can // properly fallback on v1 when an image is not found. client.Transport = AuthTransport(client.Transport, authConfig, alwaysSetBasicAuth) jar, err := cookiejar.New(nil) if err != nil { return errors.New("cookiejar.New is not supposed to return an error") } client.Jar = jar return nil } func newSession(client *http.Client, authConfig *types.AuthConfig, endpoint *V1Endpoint) *Session { return &Session{ authConfig: authConfig, client: client, indexEndpoint: endpoint, id: stringid.GenerateRandomID(), } } // NewSession creates a new session // TODO(tiborvass): remove authConfig param once registry client v2 is vendored func NewSession(client *http.Client, authConfig *types.AuthConfig, endpoint *V1Endpoint) (*Session, error) { if err := authorizeClient(client, authConfig, endpoint); err != nil { return nil, err } return newSession(client, authConfig, endpoint), nil } // ID returns this registry session's ID. func (r *Session) ID() string { return r.id } // GetRemoteHistory retrieves the history of a given image from the registry. // It returns a list of the parent's JSON files (including the requested image). func (r *Session) GetRemoteHistory(imgID, registry string) ([]string, error) { res, err := r.client.Get(registry + "images/" + imgID + "/ancestry") if err != nil { return nil, err } defer res.Body.Close() if res.StatusCode != http.StatusOK { if res.StatusCode == http.StatusUnauthorized { return nil, errcode.ErrorCodeUnauthorized.WithArgs() } return nil, newJSONError(fmt.Sprintf("Server error: %d trying to fetch remote history for %s", res.StatusCode, imgID), res) } var history []string if err := json.NewDecoder(res.Body).Decode(&history); err != nil { return nil, fmt.Errorf("Error while reading the http response: %v", err) } logrus.Debugf("Ancestry: %v", history) return history, nil } // LookupRemoteImage checks if an image exists in the registry func (r *Session) LookupRemoteImage(imgID, registry string) error { res, err := r.client.Get(registry + "images/" + imgID + "/json") if err != nil { return err } res.Body.Close() if res.StatusCode != http.StatusOK { return newJSONError(fmt.Sprintf("HTTP code %d", res.StatusCode), res) } return nil } // GetRemoteImageJSON retrieves an image's JSON metadata from the registry. func (r *Session) GetRemoteImageJSON(imgID, registry string) ([]byte, int64, error) { res, err := r.client.Get(registry + "images/" + imgID + "/json") if err != nil { return nil, -1, fmt.Errorf("Failed to download json: %s", err) } defer res.Body.Close() if res.StatusCode != http.StatusOK { return nil, -1, newJSONError(fmt.Sprintf("HTTP code %d", res.StatusCode), res) } // if the size header is not present, then set it to '-1' imageSize := int64(-1) if hdr := res.Header.Get("X-Docker-Size"); hdr != "" { imageSize, err = strconv.ParseInt(hdr, 10, 64) if err != nil { return nil, -1, err } } jsonString, err := ioutil.ReadAll(res.Body) if err != nil { return nil, -1, fmt.Errorf("Failed to parse downloaded json: %v (%s)", err, jsonString) } return jsonString, imageSize, nil } // GetRemoteImageLayer retrieves an image layer from the registry func (r *Session) GetRemoteImageLayer(imgID, registry string, imgSize int64) (io.ReadCloser, error) { var ( statusCode = 0 res *http.Response err error imageURL = fmt.Sprintf("%simages/%s/layer", registry, imgID) ) req, err := http.NewRequest(http.MethodGet, imageURL, nil) if err != nil { return nil, fmt.Errorf("Error while getting from the server: %v", err) } res, err = r.client.Do(req) if err != nil { logrus.Debugf("Error contacting registry %s: %v", registry, err) // the only case err != nil && res != nil is https://golang.org/src/net/http/client.go#L515 if res != nil { if res.Body != nil { res.Body.Close() } statusCode = res.StatusCode } return nil, fmt.Errorf("Server error: Status %d while fetching image layer (%s)", statusCode, imgID) } if res.StatusCode != http.StatusOK { res.Body.Close() return nil, fmt.Errorf("Server error: Status %d while fetching image layer (%s)", res.StatusCode, imgID) } if res.Header.Get("Accept-Ranges") == "bytes" && imgSize > 0 { logrus.Debug("server supports resume") return resumable.NewRequestReaderWithInitialResponse(r.client, req, 5, imgSize, res), nil } logrus.Debug("server doesn't support resume") return res.Body, nil } // GetRemoteTag retrieves the tag named in the askedTag argument from the given // repository. It queries each of the registries supplied in the registries // argument, and returns data from the first one that answers the query // successfully. func (r *Session) GetRemoteTag(registries []string, repositoryRef reference.Named, askedTag string) (string, error) { repository := reference.Path(repositoryRef) if strings.Count(repository, "/") == 0 { // This will be removed once the registry supports auto-resolution on // the "library" namespace repository = "library/" + repository } for _, host := range registries { endpoint := fmt.Sprintf("%srepositories/%s/tags/%s", host, repository, askedTag) res, err := r.client.Get(endpoint) if err != nil { return "", err } logrus.Debugf("Got status code %d from %s", res.StatusCode, endpoint) defer res.Body.Close() if res.StatusCode == 404 { return "", ErrRepoNotFound } if res.StatusCode != http.StatusOK { continue } var tagID string if err := json.NewDecoder(res.Body).Decode(&tagID); err != nil { return "", err } return tagID, nil } return "", fmt.Errorf("Could not reach any registry endpoint") } // GetRemoteTags retrieves all tags from the given repository. It queries each // of the registries supplied in the registries argument, and returns data from // the first one that answers the query successfully. It returns a map with // tag names as the keys and image IDs as the values. func (r *Session) GetRemoteTags(registries []string, repositoryRef reference.Named) (map[string]string, error) { repository := reference.Path(repositoryRef) if strings.Count(repository, "/") == 0 { // This will be removed once the registry supports auto-resolution on // the "library" namespace repository = "library/" + repository } for _, host := range registries { endpoint := fmt.Sprintf("%srepositories/%s/tags", host, repository) res, err := r.client.Get(endpoint) if err != nil { return nil, err } logrus.Debugf("Got status code %d from %s", res.StatusCode, endpoint) defer res.Body.Close() if res.StatusCode == 404 { return nil, ErrRepoNotFound } if res.StatusCode != http.StatusOK { continue } result := make(map[string]string) if err := json.NewDecoder(res.Body).Decode(&result); err != nil { return nil, err } return result, nil } return nil, fmt.Errorf("Could not reach any registry endpoint") } func buildEndpointsList(headers []string, indexEp string) ([]string, error) { var endpoints []string parsedURL, err := url.Parse(indexEp) if err != nil { return nil, err } var urlScheme = parsedURL.Scheme // The registry's URL scheme has to match the Index' for _, ep := range headers { epList := strings.Split(ep, ",") for _, epListElement := range epList { endpoints = append( endpoints, fmt.Sprintf("%s://%s/v1/", urlScheme, strings.TrimSpace(epListElement))) } } return endpoints, nil } // GetRepositoryData returns lists of images and endpoints for the repository func (r *Session) GetRepositoryData(name reference.Named) (*RepositoryData, error) { repositoryTarget := fmt.Sprintf("%srepositories/%s/images", r.indexEndpoint.String(), reference.Path(name)) logrus.Debugf("[registry] Calling GET %s", repositoryTarget) req, err := http.NewRequest(http.MethodGet, repositoryTarget, nil) if err != nil { return nil, err } // this will set basic auth in r.client.Transport and send cached X-Docker-Token headers for all subsequent requests req.Header.Set("X-Docker-Token", "true") res, err := r.client.Do(req) if err != nil { // check if the error is because of i/o timeout // and return a non-obtuse error message for users // "Get https://index.docker.io/v1/repositories/library/busybox/images: i/o timeout" // was a top search on the docker user forum if isTimeout(err) { return nil, fmt.Errorf("network timed out while trying to connect to %s. You may want to check your internet connection or if you are behind a proxy", repositoryTarget) } return nil, fmt.Errorf("Error while pulling image: %v", err) } defer res.Body.Close() if res.StatusCode == http.StatusUnauthorized { return nil, errcode.ErrorCodeUnauthorized.WithArgs() } // TODO: Right now we're ignoring checksums in the response body. // In the future, we need to use them to check image validity. if res.StatusCode == 404 { return nil, newJSONError(fmt.Sprintf("HTTP code: %d", res.StatusCode), res) } else if res.StatusCode != http.StatusOK { errBody, err := ioutil.ReadAll(res.Body) if err != nil { logrus.Debugf("Error reading response body: %s", err) } return nil, newJSONError(fmt.Sprintf("Error: Status %d trying to pull repository %s: %q", res.StatusCode, reference.Path(name), errBody), res) } var endpoints []string if res.Header.Get("X-Docker-Endpoints") != "" { endpoints, err = buildEndpointsList(res.Header["X-Docker-Endpoints"], r.indexEndpoint.String()) if err != nil { return nil, err } } else { // Assume the endpoint is on the same host endpoints = append(endpoints, fmt.Sprintf("%s://%s/v1/", r.indexEndpoint.URL.Scheme, req.URL.Host)) } remoteChecksums := []*ImgData{} if err := json.NewDecoder(res.Body).Decode(&remoteChecksums); err != nil { return nil, err } // Forge a better object from the retrieved data imgsData := make(map[string]*ImgData, len(remoteChecksums)) for _, elem := range remoteChecksums { imgsData[elem.ID] = elem } return &RepositoryData{ ImgList: imgsData, Endpoints: endpoints, }, nil } // PushImageChecksumRegistry uploads checksums for an image func (r *Session) PushImageChecksumRegistry(imgData *ImgData, registry string) error { u := registry + "images/" + imgData.ID + "/checksum" logrus.Debugf("[registry] Calling PUT %s", u) req, err := http.NewRequest(http.MethodPut, u, nil) if err != nil { return err } req.Header.Set("X-Docker-Checksum", imgData.Checksum) req.Header.Set("X-Docker-Checksum-Payload", imgData.ChecksumPayload) res, err := r.client.Do(req) if err != nil { return fmt.Errorf("Failed to upload metadata: %v", err) } defer res.Body.Close() if len(res.Cookies()) > 0 { r.client.Jar.SetCookies(req.URL, res.Cookies()) } if res.StatusCode != http.StatusOK { errBody, err := ioutil.ReadAll(res.Body) if err != nil { return fmt.Errorf("HTTP code %d while uploading metadata and error when trying to parse response body: %s", res.StatusCode, err) } var jsonBody map[string]string if err := json.Unmarshal(errBody, &jsonBody); err != nil { errBody = []byte(err.Error()) } else if jsonBody["error"] == "Image already exists" { return ErrAlreadyExists } return fmt.Errorf("HTTP code %d while uploading metadata: %q", res.StatusCode, errBody) } return nil } // PushImageJSONRegistry pushes JSON metadata for a local image to the registry func (r *Session) PushImageJSONRegistry(imgData *ImgData, jsonRaw []byte, registry string) error { u := registry + "images/" + imgData.ID + "/json" logrus.Debugf("[registry] Calling PUT %s", u) req, err := http.NewRequest(http.MethodPut, u, bytes.NewReader(jsonRaw)) if err != nil { return err } req.Header.Add("Content-type", "application/json") res, err := r.client.Do(req) if err != nil { return fmt.Errorf("Failed to upload metadata: %s", err) } defer res.Body.Close() if res.StatusCode == http.StatusUnauthorized && strings.HasPrefix(registry, "http://") { return newJSONError("HTTP code 401, Docker will not send auth headers over HTTP.", res) } if res.StatusCode != http.StatusOK { errBody, err := ioutil.ReadAll(res.Body) if err != nil { return newJSONError(fmt.Sprintf("HTTP code %d while uploading metadata and error when trying to parse response body: %s", res.StatusCode, err), res) } var jsonBody map[string]string if err := json.Unmarshal(errBody, &jsonBody); err != nil { errBody = []byte(err.Error()) } else if jsonBody["error"] == "Image already exists" { return ErrAlreadyExists } return newJSONError(fmt.Sprintf("HTTP code %d while uploading metadata: %q", res.StatusCode, errBody), res) } return nil } // PushImageLayerRegistry sends the checksum of an image layer to the registry func (r *Session) PushImageLayerRegistry(imgID string, layer io.Reader, registry string, jsonRaw []byte) (checksum string, checksumPayload string, err error) { u := registry + "images/" + imgID + "/layer" logrus.Debugf("[registry] Calling PUT %s", u) tarsumLayer, err := tarsum.NewTarSum(layer, false, tarsum.Version0) if err != nil { return "", "", err } h := sha256.New() h.Write(jsonRaw) h.Write([]byte{'\n'}) checksumLayer := io.TeeReader(tarsumLayer, h) req, err := http.NewRequest(http.MethodPut, u, checksumLayer) if err != nil { return "", "", err } req.Header.Add("Content-Type", "application/octet-stream") req.ContentLength = -1 req.TransferEncoding = []string{"chunked"} res, err := r.client.Do(req) if err != nil { return "", "", fmt.Errorf("Failed to upload layer: %v", err) } if rc, ok := layer.(io.Closer); ok { if err := rc.Close(); err != nil { return "", "", err } } defer res.Body.Close() if res.StatusCode != http.StatusOK { errBody, err := ioutil.ReadAll(res.Body) if err != nil { return "", "", newJSONError(fmt.Sprintf("HTTP code %d while uploading metadata and error when trying to parse response body: %s", res.StatusCode, err), res) } return "", "", newJSONError(fmt.Sprintf("Received HTTP code %d while uploading layer: %q", res.StatusCode, errBody), res) } checksumPayload = "sha256:" + hex.EncodeToString(h.Sum(nil)) return tarsumLayer.Sum(jsonRaw), checksumPayload, nil } // PushRegistryTag pushes a tag on the registry. // Remote has the format '/ func (r *Session) PushRegistryTag(remote reference.Named, revision, tag, registry string) error { // "jsonify" the string revision = "\"" + revision + "\"" path := fmt.Sprintf("repositories/%s/tags/%s", reference.Path(remote), tag) req, err := http.NewRequest(http.MethodPut, registry+path, strings.NewReader(revision)) if err != nil { return err } req.Header.Add("Content-type", "application/json") req.ContentLength = int64(len(revision)) res, err := r.client.Do(req) if err != nil { return err } res.Body.Close() if res.StatusCode != http.StatusOK && res.StatusCode != http.StatusCreated { return newJSONError(fmt.Sprintf("Internal server error: %d trying to push tag %s on %s", res.StatusCode, tag, reference.Path(remote)), res) } return nil } // PushImageJSONIndex uploads an image list to the repository func (r *Session) PushImageJSONIndex(remote reference.Named, imgList []*ImgData, validate bool, regs []string) (*RepositoryData, error) { cleanImgList := []*ImgData{} if validate { for _, elem := range imgList { if elem.Checksum != "" { cleanImgList = append(cleanImgList, elem) } } } else { cleanImgList = imgList } imgListJSON, err := json.Marshal(cleanImgList) if err != nil { return nil, err } var suffix string if validate { suffix = "images" } u := fmt.Sprintf("%srepositories/%s/%s", r.indexEndpoint.String(), reference.Path(remote), suffix) logrus.Debugf("[registry] PUT %s", u) logrus.Debugf("Image list pushed to index:\n%s", imgListJSON) headers := map[string][]string{ "Content-type": {"application/json"}, // this will set basic auth in r.client.Transport and send cached X-Docker-Token headers for all subsequent requests "X-Docker-Token": {"true"}, } if validate { headers["X-Docker-Endpoints"] = regs } // Redirect if necessary var res *http.Response for { if res, err = r.putImageRequest(u, headers, imgListJSON); err != nil { return nil, err } if !shouldRedirect(res) { break } res.Body.Close() u = res.Header.Get("Location") logrus.Debugf("Redirected to %s", u) } defer res.Body.Close() if res.StatusCode == http.StatusUnauthorized { return nil, errcode.ErrorCodeUnauthorized.WithArgs() } var tokens, endpoints []string if !validate { if res.StatusCode != http.StatusOK && res.StatusCode != http.StatusCreated { errBody, err := ioutil.ReadAll(res.Body) if err != nil { logrus.Debugf("Error reading response body: %s", err) } return nil, newJSONError(fmt.Sprintf("Error: Status %d trying to push repository %s: %q", res.StatusCode, reference.Path(remote), errBody), res) } tokens = res.Header["X-Docker-Token"] logrus.Debugf("Auth token: %v", tokens) if res.Header.Get("X-Docker-Endpoints") == "" { return nil, fmt.Errorf("Index response didn't contain any endpoints") } endpoints, err = buildEndpointsList(res.Header["X-Docker-Endpoints"], r.indexEndpoint.String()) if err != nil { return nil, err } } else { if res.StatusCode != http.StatusNoContent { errBody, err := ioutil.ReadAll(res.Body) if err != nil { logrus.Debugf("Error reading response body: %s", err) } return nil, newJSONError(fmt.Sprintf("Error: Status %d trying to push checksums %s: %q", res.StatusCode, reference.Path(remote), errBody), res) } } return &RepositoryData{ Endpoints: endpoints, }, nil } func (r *Session) putImageRequest(u string, headers map[string][]string, body []byte) (*http.Response, error) { req, err := http.NewRequest(http.MethodPut, u, bytes.NewReader(body)) if err != nil { return nil, err } req.ContentLength = int64(len(body)) for k, v := range headers { req.Header[k] = v } response, err := r.client.Do(req) if err != nil { return nil, err } return response, nil } func shouldRedirect(response *http.Response) bool { return response.StatusCode >= 300 && response.StatusCode < 400 } // SearchRepositories performs a search against the remote repository func (r *Session) SearchRepositories(term string, limit int) (*registrytypes.SearchResults, error) { if limit < 1 || limit > 100 { return nil, errdefs.InvalidParameter(errors.Errorf("Limit %d is outside the range of [1, 100]", limit)) } logrus.Debugf("Index server: %s", r.indexEndpoint) u := r.indexEndpoint.String() + "search?q=" + url.QueryEscape(term) + "&n=" + url.QueryEscape(fmt.Sprintf("%d", limit)) req, err := http.NewRequest(http.MethodGet, u, nil) if err != nil { return nil, errors.Wrap(errdefs.InvalidParameter(err), "Error building request") } // Have the AuthTransport send authentication, when logged in. req.Header.Set("X-Docker-Token", "true") res, err := r.client.Do(req) if err != nil { return nil, errdefs.System(err) } defer res.Body.Close() if res.StatusCode != http.StatusOK { return nil, newJSONError(fmt.Sprintf("Unexpected status code %d", res.StatusCode), res) } result := new(registrytypes.SearchResults) return result, errors.Wrap(json.NewDecoder(res.Body).Decode(result), "error decoding registry search results") } func isTimeout(err error) bool { type timeout interface { Timeout() bool } e := err switch urlErr := err.(type) { case *url.Error: e = urlErr.Err } t, ok := e.(timeout) return ok && t.Timeout() } func newJSONError(msg string, res *http.Response) error { return &jsonmessage.JSONError{ Message: msg, Code: res.StatusCode, } }