refactor: Review metrics endpoints (#1770)

Signed-off-by: Alexei Dodon <adodon@cisco.com>

pkg/api/config/config.go

@@ -340,6 +340,10 @@ func isOpenIDAuthProviderEnabled(config *Config, provider string) bool {
 	return false
 }
 
+func (c *Config) IsMetricsEnabled() bool {
+	return c.Extensions != nil && c.Extensions.Metrics != nil && *c.Extensions.Metrics.Enable
+}
+
 func (c *Config) IsSearchEnabled() bool {
 	return c.Extensions != nil && c.Extensions.Search != nil && *c.Extensions.Search.Enable
 }

pkg/api/routes.go

@@ -179,20 +179,8 @@ func (rh *RouteHandler) SetupRoutes() {
 	// gql playground
 	gqlPlayground.SetupGQLPlaygroundRoutes(prefixedRouter, rh.c.StoreController, rh.c.Log)
 
-	// setup extension routes
-	if rh.c.Config != nil {
-		// This logic needs to be reviewed, it should depend on build options
-		// not the general presence of the extensions in config
-		if rh.c.Config.Extensions == nil {
-			// minimal build
-			prefixedRouter.HandleFunc("/metrics", rh.GetMetrics).Methods("GET")
-		} else {
-			// extended build
-			ext.SetupMetricsRoutes(rh.c.Config, rh.c.Router, authHandler, rh.c.Log)
-		}
-	}
-
 	// Preconditions for enabling the actual extension routes are part of extensions themselves
+	ext.SetupMetricsRoutes(rh.c.Config, rh.c.Router, authHandler, rh.c.Log, rh.c.Metrics)
 	ext.SetupSearchRoutes(rh.c.Config, prefixedRouter, rh.c.StoreController, rh.c.MetaDB, rh.c.CveInfo,
 		rh.c.Log)
 	ext.SetupImageTrustRoutes(rh.c.Config, prefixedRouter, rh.c.MetaDB, rh.c.Log)
@@ -1860,11 +1848,6 @@ func (rh *RouteHandler) OpenIDCodeExchangeCallback() rp.CodeExchangeUserinfoCall
 	}
 }
 
-func (rh *RouteHandler) GetMetrics(w http.ResponseWriter, r *http.Request) {
-	m := rh.c.Metrics.ReceiveMetrics()
-	zcommon.WriteJSON(w, http.StatusOK, m)
-}
-
 // helper routines
 
 func getContentRange(r *http.Request) (int64 /* from */, int64 /* to */, error) {

pkg/api/session.go

@@ -113,7 +113,7 @@ func SessionLogger(ctlr *Controller) mux.MiddlewareFunc {
 				path = path + "?" + raw
 			}
 
-			if path != "/v2/metrics" {
+			if path != "/metrics" {
 				// In order to test metrics feture,the instrumentation related to node exporter
 				// should be handled by node exporter itself (ex: latency)
 				monitoring.IncHTTPConnRequests(ctlr.Metrics, method, strconv.Itoa(statusCode))

pkg/exporter/api/controller_test.go

@@ -121,6 +121,7 @@ func TestNewExporter(t *testing.T) {
 				So(servercConfig, ShouldNotBeNil)
 				baseURL := fmt.Sprintf(BaseURL, serverPort)
 				servercConfig.HTTP.Port = serverPort
+				servercConfig.BinaryType = "minimal"
 				serverController := zotapi.NewController(servercConfig)
 				So(serverController, ShouldNotBeNil)
 
@@ -149,7 +150,7 @@ func TestNewExporter(t *testing.T) {
 				}
 
 				// Side effect of calling this endpoint is that it will enable metrics
-				resp, err := resty.R().Get(baseURL + "/v2/metrics")
+				resp, err := resty.R().Get(baseURL + "/metrics")
 				So(resp, ShouldNotBeNil)
 				So(err, ShouldBeNil)
 				So(resp.StatusCode(), ShouldEqual, 200)

pkg/extensions/extension_metrics.go

@@ -8,12 +8,12 @@ import (
 	"github.com/prometheus/client_golang/prometheus/promhttp"
 
 	"zotregistry.io/zot/pkg/api/config"
+	"zotregistry.io/zot/pkg/extensions/monitoring"
 	"zotregistry.io/zot/pkg/log"
 )
 
 func EnableMetricsExtension(config *config.Config, log log.Logger, rootDir string) {
-	if config.Extensions.Metrics != nil &&
-		*config.Extensions.Metrics.Enable &&
+	if config.IsMetricsEnabled() &&
 		config.Extensions.Metrics.Prometheus != nil {
 		if config.Extensions.Metrics.Prometheus.Path == "" {
 			config.Extensions.Metrics.Prometheus.Path = "/metrics"
@@ -26,11 +26,11 @@ func EnableMetricsExtension(config *config.Config, log log.Logger, rootDir strin
 }
 
 func SetupMetricsRoutes(config *config.Config, router *mux.Router,
-	authFunc mux.MiddlewareFunc, log log.Logger,
+	authFunc mux.MiddlewareFunc, log log.Logger, metrics monitoring.MetricServer,
 ) {
 	log.Info().Msg("setting up metrics routes")
 
-	if config.Extensions.Metrics != nil && *config.Extensions.Metrics.Enable {
+	if config.IsMetricsEnabled() {
 		extRouter := router.PathPrefix(config.Extensions.Metrics.Prometheus.Path).Subrouter()
 		extRouter.Use(authFunc)
 		extRouter.Methods("GET").Handler(promhttp.Handler())

pkg/extensions/extension_metrics_disabled.go

@@ -4,9 +4,13 @@
 package extensions
 
 import (
+	"net/http"
+
 	"github.com/gorilla/mux"
 
 	"zotregistry.io/zot/pkg/api/config"
+	zcommon "zotregistry.io/zot/pkg/common"
+	"zotregistry.io/zot/pkg/extensions/monitoring"
 	"zotregistry.io/zot/pkg/log"
 )
 
@@ -18,8 +22,12 @@ func EnableMetricsExtension(config *config.Config, log log.Logger, rootDir strin
 
 // SetupMetricsRoutes ...
 func SetupMetricsRoutes(conf *config.Config, router *mux.Router,
-	authFunc mux.MiddlewareFunc, log log.Logger,
+	authFunc mux.MiddlewareFunc, log log.Logger, metrics monitoring.MetricServer,
 ) {
-	log.Warn().Msg("skipping setting up metrics routes because given zot binary doesn't include this feature," +
-		"please build a binary that does so")
+	getMetrics := func(w http.ResponseWriter, r *http.Request) {
+		m := metrics.ReceiveMetrics()
+		zcommon.WriteJSON(w, http.StatusOK, m)
+	}
+
+	router.HandleFunc("/metrics", getMetrics).Methods("GET")
 }

pkg/extensions/monitoring/minimal_client.go

@@ -60,7 +60,7 @@ func NewMetricsClient(config *MetricsConfig, logger log.Logger) *MetricsClient {
 
 func (mc *MetricsClient) GetMetrics() (*MetricsInfo, error) {
 	metrics := &MetricsInfo{}
-	if _, err := mc.makeGETRequest(mc.config.Address+"/v2/metrics", metrics); err != nil {
+	if _, err := mc.makeGETRequest(mc.config.Address+"/metrics", metrics); err != nil {
 		return nil, err
 	}