chore: add basic IT for metrics

build/testing/integration/api/api.go

@@ -4,6 +4,7 @@ import (
 	"context"
 	"encoding/json"
 	"fmt"
+	"io"
 	"net/http"
 	"testing"
 
@@ -1262,6 +1263,38 @@ func API(t *testing.T, ctx context.Context, client sdk.SDK, opts integration.Tes
 		})
 	})
 
+	t.Run("Metrics", func(t *testing.T) {
+		if authConfig.Required() {
+			t.Skip("Skipping metrics test for now as it requires authentication")
+		}
+
+		if protocol == integration.ProtocolGRPC {
+			t.Skip("Skipping metrics test for now as it requires HTTP/HTTPS protocol")
+		}
+
+		t.Log(`Ensure /metrics endpoint is reachable.`)
+
+		resp, err := http.Get(fmt.Sprintf("%s/metrics", addr))
+		require.NoError(t, err)
+
+		require.NotNil(t, resp)
+
+		assert.Equal(t, resp.StatusCode, http.StatusOK)
+
+		t.Log(`Ensure /metrics endpoint returns expected content type.`)
+
+		assert.Contains(t, resp.Header.Get("Content-Type"), "text/plain; version=0.0.4")
+
+		t.Log(`Ensure /metrics endpoint returns expected metrics.`)
+
+		body, err := io.ReadAll(resp.Body)
+		require.NoError(t, err)
+
+		defer resp.Body.Close()
+
+		assert.Contains(t, string(body), "flipt_evaluations_requests_total")
+	})
+
 	t.Run("Delete", func(t *testing.T) {
 		if !namespaceIsDefault(namespace) {
 			t.Log(`Namespace with flags fails.`)

build/testing/integration/integration.go

@@ -64,9 +64,17 @@ func (a AuthConfig) NamespaceScoped() bool {
 	return a == StaticTokenAuthNamespaced
 }
 
+type Protocol string
+
+const (
+	ProtocolHTTP  Protocol = "http"
+	ProtocolHTTPS Protocol = "https"
+	ProtocolGRPC  Protocol = "grpc"
+)
+
 type TestOpts struct {
 	Addr       string
-	Protocol   string
+	Protocol   Protocol
 	Namespace  string
 	AuthConfig AuthConfig
 	References bool
@@ -75,14 +83,16 @@ type TestOpts struct {
 func Harness(t *testing.T, fn func(t *testing.T, sdk sdk.SDK, opts TestOpts)) {
 	var transport sdk.Transport
 
-	protocol, host, _ := strings.Cut(*fliptAddr, "://")
+	p, host, _ := strings.Cut(*fliptAddr, "://")
+	protocol := Protocol(p)
+
 	switch protocol {
-	case "grpc":
+	case ProtocolGRPC:
 		conn, err := grpc.Dial(host, grpc.WithTransportCredentials(insecure.NewCredentials()))
 		require.NoError(t, err)
 
 		transport = sdkgrpc.NewTransport(conn)
-	case "http", "https":
+	case ProtocolHTTP, ProtocolHTTPS:
 		transport = sdkhttp.NewTransport(fmt.Sprintf("%s://%s", protocol, host))
 	default:
 		t.Fatalf("Unexpected flipt address protocol %s://%s", protocol, host)