[coordinator] Fix panic in Ready endpoint for admin coordinator (#3335)

m3db · Mar 8, 2021 · b91dd5c · b91dd5c
1 parent 73a98e6
commit b91dd5c
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Showing 2 changed files with 30 additions and 3 deletions.
diff --git a/src/query/api/v1/handler/ready.go b/src/query/api/v1/handler/ready.go
@@ -90,10 +90,12 @@ func (h *ReadyHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 		return
 	}
 
-	var (
+	var namespaces m3.ClusterNamespaces
+	if h.clusters != nil {
 		namespaces = h.clusters.ClusterNamespaces()
-		result     = &readyResult{}
-	)
+	}
+
+	result := &readyResult{}
 	for _, ns := range namespaces {
 		attrs := ns.Options().Attributes()
 		nsResult := readyResultNamespace{

diff --git a/src/query/api/v1/handler/ready_test.go b/src/query/api/v1/handler/ready_test.go
@@ -211,3 +211,28 @@ func TestReadyHandler(t *testing.T) {
 		})
 	}
 }
+
+func TestReadyHandlerNoClusters(t *testing.T) {
+	ctrl := xtest.NewController(t)
+	defer ctrl.Finish()
+
+	opts := options.EmptyHandlerOptions()
+	readyHandler := NewReadyHandler(opts)
+
+	w := httptest.NewRecorder()
+	url := ReadyURL
+	req := httptest.NewRequest(ReadyHTTPMethod, url, nil)
+
+	readyHandler.ServeHTTP(w, req)
+
+	resp := w.Result()
+	defer resp.Body.Close()
+	body, err := ioutil.ReadAll(resp.Body)
+	assert.NoError(t, err)
+	assert.Equal(t, http.StatusOK, resp.StatusCode)
+
+	expected := "{}"
+	actual := xtest.MustPrettyJSONString(t, string(body))
+
+	assert.Equal(t, expected, actual, xtest.Diff(expected, actual))
+}