Add end-2-end tests for label endpoints

Author: Blagoj Atanasovski

pkg/internal/testhelpers/PromTestDockerfile

@@ -0,0 +1,2 @@
+FROM prom/prometheus
+ADD prometheus.yml /etc/prometheus/prometheus.yml

pkg/internal/testhelpers/containers.go

@@ -8,10 +8,9 @@ import (
 	"context"
 	"fmt"
 	"io/ioutil"
-	"runtime"
-
 	"os"
 	"path/filepath"
+	"runtime"
 	"testing"
 
 	"github.com/docker/go-connections/nat"
@@ -26,8 +25,9 @@ const (
 	defaultDB       = "postgres"
 	connectTemplate = "postgres://%s:password@%s:%d/%s"
 
-	postgresUser = "postgres"
-	promUser     = "prom"
+	postgresUser    = "postgres"
+	promUser        = "prom"
+	emptyPromConfig = "global:\n  scrape_interval: 10s"
 
 	Superuser   = true
 	NoSuperuser = false
@@ -208,14 +208,19 @@ func StartPromContainer(storagePath string, ctx context.Context) (testcontainers
 		return nil, err
 	}
 
+	promConfigFile := filepath.Join(storagePath, "prometheus.yml")
+	err = ioutil.WriteFile(promConfigFile, []byte(emptyPromConfig), 0777)
+	if err != nil {
+		return nil, err
+	}
 	prometheusPort := nat.Port("9090/tcp")
-
 	req := testcontainers.ContainerRequest{
 		Image:        "prom/prometheus",
 		ExposedPorts: []string{string(prometheusPort)},
 		WaitingFor:   wait.ForListeningPort(prometheusPort),
 		BindMounts: map[string]string{
-			storagePath: "/prometheus",
+			storagePath:    "/prometheus",
+			promConfigFile: "/etc/prometheus/prometheus.yml",
 		},
 	}
 	container, err := testcontainers.GenericContainer(ctx, testcontainers.GenericContainerRequest{
@@ -225,7 +230,6 @@ func StartPromContainer(storagePath string, ctx context.Context) (testcontainers
 	if err != nil {
 		return nil, err
 	}
-
 	PromHost, err = container.Host(ctx)
 	if err != nil {
 		return nil, err

pkg/pgmodel/end_to_end_tests/promql_endpoint_integration_test.go

@@ -102,6 +102,20 @@ func getLabelsRequest(apiUrl string) (*http.Request, error) {
 	)
 }
 
+func getLabelNamesRequest(apiUrl string) (*http.Request, error) {
+	u, err := url.Parse(fmt.Sprintf("%s/labels", apiUrl))
+
+	if err != nil {
+		return nil, err
+	}
+
+	return http.NewRequest(
+		"GET",
+		u.String(),
+		nil,
+	)
+}
+
 func getLabelValuesRequest(apiUrl string, labelName string) (*http.Request, error) {
 	u, err := url.Parse(fmt.Sprintf("%s/label/%s/values", apiUrl, labelName))
 
@@ -369,7 +383,7 @@ func TestPromQLQueryEndpoint(t *testing.T) {
 	})
 }
 
-func TestPromQLLabelsEndpoint(t *testing.T) {
+func TestPromQLLabelEndpoints(t *testing.T) {
 	if testing.Short() || !*useDocker {
 		t.Skip("skipping integration test")
 	}
@@ -390,24 +404,26 @@ func TestPromQLLabelsEndpoint(t *testing.T) {
 		r := pgmodel.NewPgxReader(readOnly, nil)
 		queryable := query.NewQueryable(r.GetQuerier())
 
-		//labelNamesHandler := api.Labels(queryable)
+		labelNamesHandler := api.Labels(queryable)
 		labelValuesHandler := api.LabelValues(queryable)
 		router := route.New()
 		router.Get("/api/v1/label/:name/values", labelValuesHandler.ServeHTTP)
-
+		router.Get("/api/v1/labels", labelNamesHandler.ServeHTTP)
 		apiURL := fmt.Sprintf("http://%s:%d/api/v1", testhelpers.PromHost, testhelpers.PromPort.Int())
 		client := &http.Client{Timeout: 10 * time.Second}
 
 		var (
 			req *http.Request
 			err error
 		)
-		//req, err = getLabelsRequest(apiURL)
-		//if err != nil {
-		//	t.Fatalf("unable to create PromQL labels request: %v", err)
-		//}
-		//testMethod := testRequest(req, labelNamesHandler, client, labelsResultComparator)
-		//tester.Run("get all labels", testMethod)
+		req, err = getLabelNamesRequest(apiURL)
+		if err != nil {
+			t.Fatalf("unable to create PromQL label names request: %v", err)
+		}
+
+		testMethod := testRequest(req, router, client, labelsResultComparator)
+		tester.Run("get label names", testMethod)
+
 		labelNames, err := r.GetQuerier().LabelNames()
 		if err != nil {
 			t.Fatalf("could not get label names from querier")