Add tests for metrics server check

pkg/controller/observer_test.go

@@ -10,7 +10,6 @@ import (
 func TestCanaryObserver_GetDeploymentCounter(t *testing.T) {
 	ts := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
 		json := `{"status":"success","data":{"resultType":"vector","result":[{"metric":{},"value":[1545905245.458,"100"]}]}}`
-		w.WriteHeader(http.StatusAccepted)
 		w.Write([]byte(json))
 	}))
 	defer ts.Close()
@@ -33,7 +32,6 @@ func TestCanaryObserver_GetDeploymentCounter(t *testing.T) {
 func TestCanaryObserver_GetDeploymentHistogram(t *testing.T) {
 	ts := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
 		json := `{"status":"success","data":{"resultType":"vector","result":[{"metric":{},"value":[1545905245.596,"0.2"]}]}}`
-		w.WriteHeader(http.StatusAccepted)
 		w.Write([]byte(json))
 	}))
 	defer ts.Close()
@@ -51,3 +49,36 @@ func TestCanaryObserver_GetDeploymentHistogram(t *testing.T) {
 		t.Errorf("Got %v wanted %v", val, 200*time.Millisecond)
 	}
 }
+
+func TestCheckMetricsServer(t *testing.T) {
+	ts := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		json := `{"status":"success","data":{"config.file":"/etc/prometheus/prometheus.yml"}}`
+		w.Write([]byte(json))
+	}))
+	defer ts.Close()
+
+	ok, err := CheckMetricsServer(ts.URL)
+	if err != nil {
+		t.Fatal(err.Error())
+	}
+
+	if !ok {
+		t.Errorf("Got %v wanted %v", ok, true)
+	}
+}
+
+func TestCheckMetricsServer_Offline(t *testing.T) {
+	ts := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		w.WriteHeader(http.StatusBadGateway)
+	}))
+	defer ts.Close()
+
+	ok, err := CheckMetricsServer(ts.URL)
+	if err == nil {
+		t.Errorf("Got no error wanted %v", http.StatusBadGateway)
+	}
+
+	if ok {
+		t.Errorf("Got %v wanted %v", ok, true)
+	}
+}