prometheus/cmd/prometheus/features_test.go
Julien Pivotto a5671a002f API: Add a /api/v1/features endpoint
Signed-off-by: Julien Pivotto <291750+roidelapluie@users.noreply.github.com>
2025-12-09 16:13:14 +01:00

125 lines
3.9 KiB
Go

// Copyright The Prometheus Authors
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package main
import (
"bytes"
"encoding/json"
"flag"
"fmt"
"io"
"net/http"
"os"
"path/filepath"
"testing"
"time"
"github.com/stretchr/testify/require"
"github.com/prometheus/prometheus/util/testutil"
)
var updateFeatures = flag.Bool("update-features", false, "update features.json golden file")
func TestFeaturesAPI(t *testing.T) {
if testing.Short() {
t.Skip("skipping test in short mode.")
}
t.Parallel()
tmpDir := t.TempDir()
configFile := filepath.Join(tmpDir, "prometheus.yml")
require.NoError(t, os.WriteFile(configFile, []byte{}, 0o644))
port := testutil.RandomUnprivilegedPort(t)
prom := prometheusCommandWithLogging(
t,
configFile,
port,
fmt.Sprintf("--storage.tsdb.path=%s", tmpDir),
)
require.NoError(t, prom.Start())
baseURL := fmt.Sprintf("http://127.0.0.1:%d", port)
// Wait for Prometheus to be ready.
require.Eventually(t, func() bool {
resp, err := http.Get(baseURL + "/-/ready")
if err != nil {
return false
}
defer resp.Body.Close()
return resp.StatusCode == http.StatusOK
}, 10*time.Second, 100*time.Millisecond, "Prometheus didn't become ready in time")
// Fetch features from the API.
resp, err := http.Get(baseURL + "/api/v1/features")
require.NoError(t, err)
defer resp.Body.Close()
require.Equal(t, http.StatusOK, resp.StatusCode)
body, err := io.ReadAll(resp.Body)
require.NoError(t, err)
// Parse API response.
var apiResponse struct {
Status string `json:"status"`
Data map[string]map[string]bool `json:"data"`
}
require.NoError(t, json.Unmarshal(body, &apiResponse))
require.Equal(t, "success", apiResponse.Status)
goldenPath := filepath.Join("testdata", "features.json")
// If update flag is set, write the current features to the golden file.
if *updateFeatures {
var buf bytes.Buffer
encoder := json.NewEncoder(&buf)
encoder.SetEscapeHTML(false)
encoder.SetIndent("", " ")
require.NoError(t, encoder.Encode(apiResponse.Data))
// Ensure testdata directory exists.
require.NoError(t, os.MkdirAll(filepath.Dir(goldenPath), 0o755))
require.NoError(t, os.WriteFile(goldenPath, buf.Bytes(), 0o644))
t.Logf("Updated golden file: %s", goldenPath)
return
}
// Load golden file.
goldenData, err := os.ReadFile(goldenPath)
require.NoError(t, err, "Failed to read golden file %s. Run 'make update-features-testdata' to generate it.", goldenPath)
var expectedFeatures map[string]map[string]bool
require.NoError(t, json.Unmarshal(goldenData, &expectedFeatures))
// The labels implementation depends on build tags (stringlabels, slicelabels, or dedupelabels).
// We need to update the expected features to match the current build.
if prometheusFeatures, ok := expectedFeatures["prometheus"]; ok {
// Remove all label implementation features from expected.
delete(prometheusFeatures, "stringlabels")
delete(prometheusFeatures, "slicelabels")
delete(prometheusFeatures, "dedupelabels")
// Add the current implementation.
if actualPrometheus, ok := apiResponse.Data["prometheus"]; ok {
for _, impl := range []string{"stringlabels", "slicelabels", "dedupelabels"} {
if actualPrometheus[impl] {
prometheusFeatures[impl] = true
}
}
}
}
// Compare the features data with the golden file.
require.Equal(t, expectedFeatures, apiResponse.Data, "Features mismatch. Run 'make update-features-testdata' to update the golden file.")
}