Fix uploading layer blobs to Docker registry

Implement a client to the chunked API, instead of the nonexistent
one-shot API (per
2a4deee441
).

Adds a FIXME to DELETE the pending upload on failure; the uploads are
supposed to time out so this is not immediately critical.

Fixes #64 .

docker/docker_client.go

@@ -29,7 +29,7 @@ const (
 	tagsURL       = "%s/tags/list"
 	manifestURL   = "%s/manifests/%s"
 	blobsURL      = "%s/blobs/%s"
-	blobUploadURL = "%s/blobs/uploads/?digest=%s"
+	blobUploadURL = "%s/blobs/uploads/"
 )
 
 // dockerClient is configuration for dealing with a single Docker registry.
@@ -78,6 +78,8 @@ func newDockerClient(refHostname, certPath string, tlsVerify bool) (*dockerClien
 	}, nil
 }
 
+// makeRequest creates and executes a http.Request with the specified parameters, adding authentication and TLS options for the Docker client.
+// url is NOT an absolute URL, but a path relative to the /v2/ top-level API path.  The host name and schema is taken from the client or autodetected.
 func (c *dockerClient) makeRequest(method, url string, headers map[string][]string, stream io.Reader) (*http.Response, error) {
 	if c.scheme == "" {
 		pr, err := c.ping()
@@ -89,6 +91,12 @@ func (c *dockerClient) makeRequest(method, url string, headers map[string][]stri
 	}
 
 	url = fmt.Sprintf(baseURL, c.scheme, c.registry) + url
+	return c.makeRequestToResolvedURL(method, url, headers, stream)
+}
+
+// makeRequestToResolvedURL creates and executes a http.Request with the specified parameters, adding authentication and TLS options for the Docker client.
+// makeRequest should generally be preferred.
+func (c *dockerClient) makeRequestToResolvedURL(method, url string, headers map[string][]string, stream io.Reader) (*http.Response, error) {
 	req, err := http.NewRequest(method, url, stream)
 	if err != nil {
 		return nil, err

docker/docker_image_dest.go

@@ -86,19 +86,38 @@ func (d *dockerImageDestination) PutLayer(digest string, stream io.Reader) error
 	logrus.Debugf("... failed, status %d", res.StatusCode)
 
 	// FIXME? Chunked upload, progress reporting, etc.
-	uploadURL := fmt.Sprintf(blobUploadURL, d.ref.RemoteName(), digest)
+	uploadURL := fmt.Sprintf(blobUploadURL, d.ref.RemoteName())
 	logrus.Debugf("Uploading %s", uploadURL)
-	// FIXME: Set Content-Length?
+	res, err = d.c.makeRequest("POST", uploadURL, nil, nil)
-	res, err = d.c.makeRequest("POST", uploadURL, map[string][]string{"Content-Type": {"application/octet-stream"}}, stream)
+	if err != nil {
+		return err
+	}
+	defer res.Body.Close()
+	if res.StatusCode != http.StatusAccepted {
+		logrus.Debugf("Error initiating layer upload, response %#v", *res)
+		return fmt.Errorf("Error initiating layer upload to %s, status %d", uploadURL, res.StatusCode)
+	}
+	uploadLocation, err := res.Location()
+	if err != nil {
+		return fmt.Errorf("Error determining upload URL: %s", err.Error())
+	}
+
+	// FIXME: DELETE uploadLocation on failure
+
+	locationQuery := uploadLocation.Query()
+	locationQuery.Set("digest", digest)
+	uploadLocation.RawQuery = locationQuery.Encode()
+	res, err = d.c.makeRequestToResolvedURL("PUT", uploadLocation.String(), map[string][]string{"Content-Type": {"application/octet-stream"}}, stream)
 	if err != nil {
 		return err
 	}
 	defer res.Body.Close()
 	if res.StatusCode != http.StatusCreated {
-		logrus.Debugf("Error uploading, status %d", res.StatusCode)
+		logrus.Debugf("Error uploading layer, response %#v", *res)
-		return fmt.Errorf("Error uploading to %s, status %d", uploadURL, res.StatusCode)
+		return fmt.Errorf("Error uploading layer to %s, status %d", uploadLocation, res.StatusCode)
 	}
 
+	logrus.Debugf("Upload of layer %s complete", digest)
 	return nil
 }