Support Prometheus /api/v1/status/buildinfo API on Querier/QFE (#4978)

* support Prometheus /api/v1/status/buildinfo API

Signed-off-by: Ben Ye <[email protected]>

* add unit test

Signed-off-by: Ben Ye <[email protected]>

* update api doc

Signed-off-by: Ben Ye <[email protected]>

* revert docs update

Signed-off-by: Ben Ye <[email protected]>

Signed-off-by: Ben Ye <[email protected]>

Author: yeya24

CHANGELOG.md

@@ -1,6 +1,7 @@
 # Changelog
 
 ## master / unreleased
+* [FEATURE] Querier/Query Frontend: support Prometheus /api/v1/status/buildinfo API. #4978
 
 ## 1.14.0 in progress
 

pkg/api/api.go

@@ -352,7 +352,7 @@ type Distributor interface {
 	UserStatsHandler(w http.ResponseWriter, r *http.Request)
 }
 
-// RegisterQueryable registers the the default routes associated with the querier
+// RegisterQueryable registers the default routes associated with the querier
 // module.
 func (a *API) RegisterQueryable(
 	queryable storage.SampleAndChunkQueryable,
@@ -374,6 +374,7 @@ func (a *API) RegisterQueryAPI(handler http.Handler) {
 	a.RegisterRoute(path.Join(a.cfg.PrometheusHTTPPrefix, "/api/v1/label/{name}/values"), handler, true, "GET")
 	a.RegisterRoute(path.Join(a.cfg.PrometheusHTTPPrefix, "/api/v1/series"), handler, true, "GET", "POST", "DELETE")
 	a.RegisterRoute(path.Join(a.cfg.PrometheusHTTPPrefix, "/api/v1/metadata"), handler, true, "GET")
+	a.RegisterRoute(path.Join(a.cfg.PrometheusHTTPPrefix, "/api/v1/status/buildinfo"), handler, true, "GET")
 
 	// Register Legacy Routers
 	a.RegisterRoute(path.Join(a.cfg.LegacyHTTPPrefix, "/api/v1/read"), handler, true, "POST")
@@ -384,6 +385,7 @@ func (a *API) RegisterQueryAPI(handler http.Handler) {
 	a.RegisterRoute(path.Join(a.cfg.LegacyHTTPPrefix, "/api/v1/label/{name}/values"), handler, true, "GET")
 	a.RegisterRoute(path.Join(a.cfg.LegacyHTTPPrefix, "/api/v1/series"), handler, true, "GET", "POST", "DELETE")
 	a.RegisterRoute(path.Join(a.cfg.LegacyHTTPPrefix, "/api/v1/metadata"), handler, true, "GET")
+	a.RegisterRoute(path.Join(a.cfg.LegacyHTTPPrefix, "/api/v1/status/buildinfo"), handler, true, "GET")
 }
 
 // RegisterQueryFrontend registers the Prometheus routes supported by the

pkg/api/handlers.go

@@ -15,6 +15,7 @@ import (
 	"github.com/prometheus/client_golang/prometheus/promauto"
 	dto "github.com/prometheus/client_model/go"
 	"github.com/prometheus/common/route"
+	"github.com/prometheus/common/version"
 	"github.com/prometheus/prometheus/config"
 	"github.com/prometheus/prometheus/storage"
 	v1 "github.com/prometheus/prometheus/web/api/v1"
@@ -211,7 +212,14 @@ func NewQuerierHandler(
 		false,
 		regexp.MustCompile(".*"),
 		func() (v1.RuntimeInfo, error) { return v1.RuntimeInfo{}, errors.New("not implemented") },
-		&v1.PrometheusVersion{},
+		&v1.PrometheusVersion{
+			Version:   version.Version,
+			Branch:    version.Branch,
+			Revision:  version.Revision,
+			BuildUser: version.BuildUser,
+			BuildDate: version.BuildDate,
+			GoVersion: version.GoVersion,
+		},
 		// This is used for the stats API which we should not support. Or find other ways to.
 		prometheus.GathererFunc(func() ([]*dto.MetricFamily, error) { return nil, nil }),
 		reg,
@@ -255,6 +263,7 @@ func NewQuerierHandler(
 	router.Path(path.Join(prefix, "/api/v1/label/{name}/values")).Methods("GET").Handler(promRouter)
 	router.Path(path.Join(prefix, "/api/v1/series")).Methods("GET", "POST", "DELETE").Handler(promRouter)
 	router.Path(path.Join(prefix, "/api/v1/metadata")).Methods("GET").Handler(promRouter)
+	router.Path(path.Join(prefix, "/api/v1/status/buildinfo")).Methods("GET").Handler(promRouter)
 
 	// TODO(gotjosh): This custom handler is temporary until we're able to vendor the changes in:
 	// https://github.com/prometheus/prometheus/pull/7125/files
@@ -268,6 +277,7 @@ func NewQuerierHandler(
 	router.Path(path.Join(legacyPrefix, "/api/v1/label/{name}/values")).Methods("GET").Handler(legacyPromRouter)
 	router.Path(path.Join(legacyPrefix, "/api/v1/series")).Methods("GET", "POST", "DELETE").Handler(legacyPromRouter)
 	router.Path(path.Join(legacyPrefix, "/api/v1/metadata")).Methods("GET").Handler(legacyPromRouter)
+	router.Path(path.Join(legacyPrefix, "/api/v1/status/buildinfo")).Methods("GET").Handler(legacyPromRouter)
 
 	// Track execution time.
 	return stats.NewWallTimeMiddleware().Wrap(router)

pkg/api/handlers_test.go

@@ -1,14 +1,21 @@
 package api
 
 import (
+	"encoding/json"
 	"io"
 	"net/http"
 	"net/http/httptest"
+	"runtime"
 	"strings"
 	"testing"
 
+	"github.com/prometheus/common/version"
+	v1 "github.com/prometheus/prometheus/web/api/v1"
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
+	"github.com/weaveworks/common/user"
+
+	"github.com/cortexproject/cortex/pkg/purger"
 )
 
 func TestIndexHandlerPrefix(t *testing.T) {
@@ -189,3 +196,56 @@ func TestConfigOverrideHandler(t *testing.T) {
 	assert.NoError(t, err)
 	assert.Equal(t, []byte("config"), body)
 }
+
+func TestBuildInfoAPI(t *testing.T) {
+	type buildInfo struct {
+		Status string               `json:"status"`
+		Data   v1.PrometheusVersion `json:"data"`
+	}
+
+	for _, tc := range []struct {
+		name     string
+		version  string
+		branch   string
+		revision string
+		expected buildInfo
+	}{
+		{
+			name: "empty",
+			expected: buildInfo{Status: "success", Data: v1.PrometheusVersion{
+				GoVersion: runtime.Version(),
+			}},
+		},
+		{
+			name:     "set versions",
+			version:  "v0.14.0",
+			branch:   "test",
+			revision: "foo",
+			expected: buildInfo{Status: "success", Data: v1.PrometheusVersion{
+				Version:   "v0.14.0",
+				Branch:    "test",
+				Revision:  "foo",
+				GoVersion: runtime.Version(),
+			}},
+		},
+	} {
+		t.Run(tc.name, func(t *testing.T) {
+			cfg := Config{}
+			version.Version = tc.version
+			version.Branch = tc.branch
+			version.Revision = tc.revision
+			handler := NewQuerierHandler(cfg, nil, nil, nil, nil, purger.NewNoopTombstonesLoader(), nil, &FakeLogger{})
+			writer := httptest.NewRecorder()
+			req := httptest.NewRequest("GET", "/api/v1/status/buildinfo", nil)
+			req = req.WithContext(user.InjectOrgID(req.Context(), "test"))
+			handler.ServeHTTP(writer, req)
+			out, err := io.ReadAll(writer.Body)
+			require.NoError(t, err)
+
+			var info buildInfo
+			err = json.Unmarshal(out, &info)
+			require.NoError(t, err)
+			require.Equal(t, tc.expected, info)
+		})
+	}
+}