Add metrics service gRPC gateway. Upgrade deps. (#608)

* Add metrics service gRPC gateway. Upgrade deps.

Fixes #607

* Use a tag for ocagent exporter

* Add a simple unit test for metrics grpc gateway

Author: songy23

go.mod

@@ -3,7 +3,7 @@ module github.com/census-instrumentation/opencensus-service
 require (
 	contrib.go.opencensus.io/exporter/aws v0.0.0-20181029163544-2befc13012d0
 	contrib.go.opencensus.io/exporter/jaeger v0.1.1-0.20190430175949-e8b55949d948
-	contrib.go.opencensus.io/exporter/ocagent v0.5.0
+	contrib.go.opencensus.io/exporter/ocagent v0.5.1
 	contrib.go.opencensus.io/exporter/prometheus v0.1.0
 	contrib.go.opencensus.io/exporter/stackdriver v0.12.3-0.20190626200219-09504ed717c7 // TODO: pin a released version
 	contrib.go.opencensus.io/exporter/zipkin v0.1.1
@@ -13,7 +13,7 @@ require (
 	github.com/VividCortex/gohistogram v1.0.0 // indirect
 	github.com/apache/thrift v0.0.0-20161221203622-b2a4d4ae21c7
 	github.com/bmizerany/perks v0.0.0-20141205001514-d9a9656a3a4b // indirect
-	github.com/census-instrumentation/opencensus-proto v0.2.0
+	github.com/census-instrumentation/opencensus-proto v0.2.1
 	github.com/go-kit/kit v0.8.0
 	github.com/gogo/googleapis v1.2.0 // indirect
 	github.com/golang/protobuf v1.3.1

go.sum

@@ -8,8 +8,8 @@ contrib.go.opencensus.io/exporter/aws v0.0.0-20181029163544-2befc13012d0 h1:YsbW
 contrib.go.opencensus.io/exporter/aws v0.0.0-20181029163544-2befc13012d0/go.mod h1:uu1P0UCM/6RbsMrgPa98ll8ZcHM858i/AD06a9aLRCA=
 contrib.go.opencensus.io/exporter/jaeger v0.1.1-0.20190430175949-e8b55949d948 h1:xdP25yLqNGSnpfDmEChwA9ZuKLdiyL0jqJKPm/Ypfag=
 contrib.go.opencensus.io/exporter/jaeger v0.1.1-0.20190430175949-e8b55949d948/go.mod h1:ukdzwIYYHgZ7QYtwVFQUjiT28BJHiMhTERo32s6qVgM=
-contrib.go.opencensus.io/exporter/ocagent v0.5.0 h1:TKXjQSRS0/cCDrP7KvkgU6SmILtF/yV2TOs/02K/WZQ=
-contrib.go.opencensus.io/exporter/ocagent v0.5.0/go.mod h1:ImxhfLRpxoYiSq891pBrLVhN+qmP8BTVvdH2YLs7Gl0=
+contrib.go.opencensus.io/exporter/ocagent v0.5.1 h1:TWb6QHJU0L63/AscynXhu5nS8fyw2uObyyYJ+YfEqPc=
+contrib.go.opencensus.io/exporter/ocagent v0.5.1/go.mod h1:oGSyf701BHqn69lMacwJJuyGzrk5eiCj86DxXhG2gfk=
 contrib.go.opencensus.io/exporter/prometheus v0.1.0 h1:SByaIoWwNgMdPSgl5sMqM2KDE5H/ukPWBRo314xiDvg=
 contrib.go.opencensus.io/exporter/prometheus v0.1.0/go.mod h1:cGFniUXGZlKRjzOyuZJ6mgB+PgBcCIa79kEKR8YCW+A=
 contrib.go.opencensus.io/exporter/stackdriver v0.12.3-0.20190626200219-09504ed717c7 h1:JLx6F8VdILk5M+2+xVZohpwN0TsC28F8WnJoPNNKogs=
@@ -65,6 +65,8 @@ github.com/cenk/backoff v2.0.0+incompatible/go.mod h1:7FtoeaSnHoZnmZzz47cM35Y9nS
 github.com/census-instrumentation/opencensus-proto v0.0.2/go.mod h1:f6KPmirojxKA12rnyqOA5BBL4O983OfeGPqjHWSTneU=
 github.com/census-instrumentation/opencensus-proto v0.2.0 h1:LzQXZOgg4CQfE6bFvXGM30YZL1WW/M337pXml+GrcZ4=
 github.com/census-instrumentation/opencensus-proto v0.2.0/go.mod h1:f6KPmirojxKA12rnyqOA5BBL4O983OfeGPqjHWSTneU=
+github.com/census-instrumentation/opencensus-proto v0.2.1 h1:glEXhBS5PSLLv4IXzLA5yPRVX4bilULVyxxbrfOtDAk=
+github.com/census-instrumentation/opencensus-proto v0.2.1/go.mod h1:f6KPmirojxKA12rnyqOA5BBL4O983OfeGPqjHWSTneU=
 github.com/certifi/gocertifi v0.0.0-20180905225744-ee1a9a0726d2/go.mod h1:GJKEexRPVJrBSOjoqN5VNOIKJ5Q3RViH6eu3puDRwx4=
 github.com/cespare/xxhash v1.1.0 h1:a6HrQnmkObjyL+Gs60czilIUGqrzKutQD6XZog3p+ko=
 github.com/cespare/xxhash v1.1.0/go.mod h1:XrSqR1VqqWfGrhpAt58auRo0WTKS1nRRg3ghfAqPWnc=

receiver/opencensusreceiver/opencensus.go

@@ -260,6 +260,12 @@ func (ocr *Receiver) startServer() error {
 				return
 			}
 
+			err = agentmetricspb.RegisterMetricsServiceHandlerFromEndpoint(c, ocr.gatewayMux, endpoint, opts)
+			if err != nil {
+				errChan <- err
+				return
+			}
+
 			// Start the gRPC and HTTP/JSON (grpc-gateway) servers on the same port.
 			m := cmux.New(ocr.ln)
 			grpcL := m.MatchWithWriters(

receiver/opencensusreceiver/opencensus_test.go

@@ -146,7 +146,7 @@ func TestGrpcGateway_endToEnd(t *testing.T) {
 	}
 }
 
-func TestGrpcGatewayCors_endToEnd(t *testing.T) {
+func TestTraceGrpcGatewayCors_endToEnd(t *testing.T) {
 	addr := ":35991"
 	corsOrigins := []string{"allowed-*.com"}
 
@@ -175,6 +175,35 @@ func TestGrpcGatewayCors_endToEnd(t *testing.T) {
 	verifyCorsResp(t, url, "disallowed-origin.com", 200, false)
 }
 
+func TestMetricsGrpcGatewayCors_endToEnd(t *testing.T) {
+	addr := ":35991"
+	corsOrigins := []string{"allowed-*.com"}
+
+	sink := new(exportertest.SinkMetricsExporter)
+	ocr, err := New(addr, nil, sink, WithCorsOrigins(corsOrigins))
+	if err != nil {
+		t.Fatalf("Failed to create metrics receiver: %v", err)
+	}
+	defer ocr.Stop()
+
+	go func() {
+		if err := ocr.StartMetricsReception(context.Background(), nil); err != nil {
+			t.Fatalf("Failed to start metrics receiver: %v", err)
+		}
+	}()
+
+	// Wait for the servers to start
+	<-time.After(10 * time.Millisecond)
+
+	url := fmt.Sprintf("http://%s/v1/metrics", addr)
+
+	// Verify allowed domain gets responses that allow CORS.
+	verifyCorsResp(t, url, "allowed-origin.com", 200, true)
+
+	// Verify disallowed domain gets responses that disallow CORS.
+	verifyCorsResp(t, url, "disallowed-origin.com", 200, false)
+}
+
 // As per Issue https://github.com/census-instrumentation/opencensus-service/issues/366
 // the agent's mux should be able to accept all Proto affiliated content-types and not
 // redirect them to the web-grpc-gateway endpoint.