Add origin readiness endpoint

core/digest.go

@@ -23,11 +23,6 @@ import (
 	"strings"
 )
 
-const (
-	// DigestEmptyTar is the sha256 digest of an empty tar file.
-	DigestEmptyTar = "sha256:e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855"
-)
-
 // DigestList is a list of digests.
 type DigestList []Digest
 

origin/blobserver/server.go

@@ -130,7 +130,8 @@ func (s *Server) Handler() http.Handler {
 	// Public endpoints:
 
 	r.Get("/health", handler.Wrap(s.healthCheckHandler))
-
+	r.Get("/readiness", handler.Wrap(s.readinessCheckHandler))
+
 	r.Get("/blobs/{digest}/locations", handler.Wrap(s.getLocationsHandler))
 
 	r.Post("/namespace/{namespace}/blobs/{digest}/uploads", handler.Wrap(s.startClusterUploadHandler))
@@ -179,6 +180,15 @@ func (s *Server) healthCheckHandler(w http.ResponseWriter, r *http.Request) erro
 	return nil
 }
 
+func (s *Server) readinessCheckHandler(w http.ResponseWriter, r *http.Request) error {
+	isReady, err := s.backends.IsReady()
+	if isReady {
+		fmt.Fprintln(w, "OK")
+		return nil
+	}
+	return handler.Errorf("not ready to serve traffic: %s", err).Status(http.StatusServiceUnavailable)
+}
+
 // statHandler returns blob info if it exists.
 func (s *Server) statHandler(w http.ResponseWriter, r *http.Request) error {
 	checkLocal, err := strconv.ParseBool(httputil.GetQueryArg(r, "local", "false"))

origin/blobserver/server_test.go

@@ -4,7 +4,7 @@
 // you may not use this file except in compliance with the License.
 // You may obtain a copy of the License at
 //
-//     http://www.apache.org/licenses/LICENSE-2.0
+//	http://www.apache.org/licenses/LICENSE-2.0
 //
 // Unless required by applicable law or agreed to in writing, software
 // distributed under the License is distributed on an "AS IS" BASIS,
@@ -53,6 +53,61 @@ func TestHealth(t *testing.T) {
 	require.Equal("OK\n", string(b))
 }
 
+func TestReadiness(t *testing.T) {
+	const isReadyNamespace = "isReadyNamespace"
+	const isReadyName = "38a03d499119bc417b8a6a016f2cb4540b9f9cc0c13e4da42a73867120d3e908"
+	for _, tc := range []struct {
+		mockStatErr error
+		expectedRes string
+		status      int
+	}{
+		{
+			mockStatErr: nil,
+			expectedRes: "OK",
+			status:      http.StatusOK,
+		},
+		{
+			mockStatErr: backenderrors.ErrBlobNotFound,
+			expectedRes: "OK",
+			status:      http.StatusOK,
+		},
+		{
+			mockStatErr: errors.New("backend error"),
+			expectedRes: "",
+			status:      http.StatusServiceUnavailable,
+		},
+	} {
+		require := require.New(t)
+
+		cp := newTestClientProvider()
+
+		s := newTestServer(t, master1, hashRingMaxReplica(), cp)
+		defer s.cleanup()
+
+		backendClient := s.backendClient(isReadyNamespace, true)
+		mockStat := &core.BlobInfo{}
+		if tc.mockStatErr != nil {
+			mockStat = nil
+		}
+		backendClient.EXPECT().Stat(isReadyNamespace, isReadyName).Return(mockStat, tc.mockStatErr)
+
+		resp, err := httputil.Get(
+			fmt.Sprintf("http://%s/readiness", s.addr))
+
+		if tc.status == http.StatusOK {
+			defer resp.Body.Close()
+			require.Equal(tc.status, resp.StatusCode)
+			require.NoError(err)
+			b, _ := ioutil.ReadAll(resp.Body)
+			require.Equal("OK\n", string(b))
+		} else {
+			require.True(httputil.IsStatus(err, tc.status))
+			require.Error(err)
+			require.Nil(resp)
+		}
+	}
+}
+
 func TestStatHandlerLocalNotFound(t *testing.T) {
 	require := require.New(t)
 
@@ -117,7 +172,7 @@ func TestStatHandlerNotFound(t *testing.T) {
 	d := core.DigestFixture()
 	namespace := core.TagFixture()
 
-	backendClient := s.backendClient(namespace)
+	backendClient := s.backendClient(namespace, false)
 
 	backendClient.EXPECT().Stat(namespace, d.Hex()).Return(nil, backenderrors.ErrBlobNotFound)
 
@@ -192,7 +247,7 @@ func TestDownloadBlobNotFound(t *testing.T) {
 	d := core.DigestFixture()
 	namespace := core.TagFixture()
 
-	backendClient := s.backendClient(namespace)
+	backendClient := s.backendClient(namespace, false)
 	backendClient.EXPECT().Stat(namespace, d.Hex()).Return(nil, backenderrors.ErrBlobNotFound)
 
 	err := cp.Provide(master1).DownloadBlob(namespace, d, ioutil.Discard)
@@ -280,7 +335,7 @@ func TestGetMetaInfoDownloadsBlobAndReplicates(t *testing.T) {
 
 	blob := computeBlobForHosts(ring, s1.host, s2.host)
 
-	backendClient := s1.backendClient(namespace)
+	backendClient := s1.backendClient(namespace, false)
 	backendClient.EXPECT().Stat(namespace,
 		blob.Digest.Hex()).Return(core.NewBlobInfo(int64(len(blob.Content))), nil).AnyTimes()
 	backendClient.EXPECT().Download(namespace, blob.Digest.Hex(), mockutil.MatchWriter(blob.Content)).Return(nil)
@@ -317,7 +372,7 @@ func TestGetMetaInfoBlobNotFound(t *testing.T) {
 	d := core.DigestFixture()
 	namespace := core.TagFixture()
 
-	backendClient := s.backendClient(namespace)
+	backendClient := s.backendClient(namespace, false)
 	backendClient.EXPECT().Stat(namespace, d.Hex()).Return(nil, backenderrors.ErrBlobNotFound)
 
 	mi, err := cp.Provide(master1).GetMetaInfo(namespace, d)
@@ -582,7 +637,7 @@ func TestReplicateToRemoteWhenBlobInStorageBackend(t *testing.T) {
 	blob := core.NewBlobFixture()
 	namespace := core.TagFixture()
 
-	backendClient := s.backendClient(namespace)
+	backendClient := s.backendClient(namespace, false)
 	backendClient.EXPECT().Stat(namespace,
 		blob.Digest.Hex()).Return(core.NewBlobInfo(int64(len(blob.Content))), nil).AnyTimes()
 	backendClient.EXPECT().Download(namespace, blob.Digest.Hex(), mockutil.MatchWriter(blob.Content)).Return(nil)

origin/blobserver/testutils_test.go

@@ -4,7 +4,7 @@
 // you may not use this file except in compliance with the License.
 // You may obtain a copy of the License at
 //
-//     http://www.apache.org/licenses/LICENSE-2.0
+//	http://www.apache.org/licenses/LICENSE-2.0
 //
 // Unless required by applicable law or agreed to in writing, software
 // distributed under the License is distributed on an "AS IS" BASIS,
@@ -158,9 +158,9 @@ func newTestServer(
 	}
 }
 
-func (s *testServer) backendClient(namespace string) *mockbackend.MockClient {
+func (s *testServer) backendClient(namespace string, mustReady bool) *mockbackend.MockClient {
 	client := mockbackend.NewMockClient(s.ctrl)
-	if err := s.backendManager.Register(namespace, client, false); err != nil {
+	if err := s.backendManager.Register(namespace, client, mustReady); err != nil {
 		panic(err)
 	}
 	return client