Add feature flag to enable build info API

CHANGELOG.md

@@ -19,6 +19,7 @@
 * [CHANGE] Store Gateway: Remove `idle_timeout`, `max_conn_age`, `pool_size`, `min_idle_conns` fields for Redis index cache and caching bucket. #5448
 * [CHANGE] Store Gateway: Add flag `-store-gateway.sharding-ring.zone-stable-shuffle-sharding` to enable store gateway to use zone stable shuffle sharding. #5489
 * [CHANGE] Bucket Index: Add `series_max_size` and `chunk_max_size` to bucket index. #5489
+* [CHANGE] Query Frontend/Querier: Make build info API disabled by default and add feature flag `api.build-info-enabled` to enable it. #5533
 * [FEATURE] Store Gateway: Add `max_downloaded_bytes_per_request` to limit max bytes to download per store gateway request.
 * [FEATURE] Added 2 flags `-alertmanager.alertmanager-client.grpc-max-send-msg-size` and ` -alertmanager.alertmanager-client.grpc-max-recv-msg-size` to configure alert manager grpc client message size limits. #5338
 * [FEATURE] Query Frontend: Add `cortex_rejected_queries_total` metric for throttled queries. #5356

docs/configuration/config-file-reference.md

@@ -91,6 +91,10 @@ api:
   # CLI flag: -server.cors-origin
   [cors_origin: <string> | default = ".*"]
 
+  # If enabled, build Info API will be served by query frontend or querier.
+  # CLI flag: -api.build-info-enabled
+  [build_info_enabled: <boolean> | default = false]
+
 # The server_config configures the HTTP and gRPC server of the launched
 # service(s).
 [server: <server_config>]

pkg/api/api.go

@@ -71,12 +71,15 @@ type Config struct {
 
 	// This sets the Origin header value
 	corsRegexString string `yaml:"cors_origin"`
+
+	buildInfoEnabled bool `yaml:"build_info_enabled"`
 }
 
 // RegisterFlags adds the flags required to config this to the given FlagSet.
 func (cfg *Config) RegisterFlags(f *flag.FlagSet) {
 	f.BoolVar(&cfg.ResponseCompression, "api.response-compression-enabled", false, "Use GZIP compression for API responses. Some endpoints serve large YAML or JSON blobs which can benefit from compression.")
 	f.Var(&cfg.HTTPRequestHeadersToLog, "api.http-request-headers-to-log", "Which HTTP Request headers to add to logs")
+	f.BoolVar(&cfg.buildInfoEnabled, "api.build-info-enabled", false, "If enabled, build Info API will be served by query frontend or querier.")
 	cfg.RegisterFlagsWithPrefix("", f)
 }
 
@@ -389,8 +392,6 @@ func (a *API) RegisterQueryable(
 
 // RegisterQueryAPI registers the Prometheus API routes with the provided handler.
 func (a *API) RegisterQueryAPI(handler http.Handler) {
-	infoHandler := &buildInfoHandler{logger: a.logger}
-
 	hf := http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
 		httputil.SetCORS(w, a.corsOrigin, r)
 		handler.ServeHTTP(w, r)
@@ -404,7 +405,6 @@ func (a *API) RegisterQueryAPI(handler http.Handler) {
 	a.RegisterRoute(path.Join(a.cfg.PrometheusHTTPPrefix, "/api/v1/label/{name}/values"), hf, true, "GET")
 	a.RegisterRoute(path.Join(a.cfg.PrometheusHTTPPrefix, "/api/v1/series"), hf, true, "GET", "POST", "DELETE")
 	a.RegisterRoute(path.Join(a.cfg.PrometheusHTTPPrefix, "/api/v1/metadata"), hf, true, "GET")
-	a.RegisterRoute(path.Join(a.cfg.PrometheusHTTPPrefix, "/api/v1/status/buildinfo"), infoHandler, true, "GET")
 
 	// Register Legacy Routers
 	a.RegisterRoute(path.Join(a.cfg.LegacyHTTPPrefix, "/api/v1/read"), hf, true, "POST")
@@ -415,11 +415,16 @@ func (a *API) RegisterQueryAPI(handler http.Handler) {
 	a.RegisterRoute(path.Join(a.cfg.LegacyHTTPPrefix, "/api/v1/label/{name}/values"), hf, true, "GET")
 	a.RegisterRoute(path.Join(a.cfg.LegacyHTTPPrefix, "/api/v1/series"), hf, true, "GET", "POST", "DELETE")
 	a.RegisterRoute(path.Join(a.cfg.LegacyHTTPPrefix, "/api/v1/metadata"), hf, true, "GET")
-	a.RegisterRoute(path.Join(a.cfg.LegacyHTTPPrefix, "/api/v1/status/buildinfo"), infoHandler, true, "GET")
+
+	if a.cfg.buildInfoEnabled {
+		infoHandler := &buildInfoHandler{logger: a.logger}
+		a.RegisterRoute(path.Join(a.cfg.PrometheusHTTPPrefix, "/api/v1/status/buildinfo"), infoHandler, true, "GET")
+		a.RegisterRoute(path.Join(a.cfg.LegacyHTTPPrefix, "/api/v1/status/buildinfo"), infoHandler, true, "GET")
+	}
 }
 
-// RegisterQueryFrontend registers the Prometheus routes supported by the
-// Cortex querier service. Currently this can not be registered simultaneously
+// RegisterQueryFrontendHandler registers the Prometheus routes supported by the
+// Cortex querier service. Currently, this can not be registered simultaneously
 // with the Querier.
 func (a *API) RegisterQueryFrontendHandler(h http.Handler) {
 	a.RegisterQueryAPI(h)

pkg/api/handlers.go

@@ -266,7 +266,6 @@ 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
@@ -280,7 +279,11 @@ 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)
+
+	if cfg.buildInfoEnabled {
+		router.Path(path.Join(prefix, "/api/v1/status/buildinfo")).Methods("GET").Handler(promRouter)
+		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

@@ -230,7 +230,7 @@ func TestBuildInfoAPI(t *testing.T) {
 		},
 	} {
 		t.Run(tc.name, func(t *testing.T) {
-			cfg := Config{}
+			cfg := Config{buildInfoEnabled: true}
 			version.Version = tc.version
 			version.Branch = tc.branch
 			version.Revision = tc.revision