Enable http metrics (#3459)

Adding config option to enable http metrics

---------

Signed-off-by: Max Knee <max.knee@nytimes.com>

cmd/drone-server/config/config.go

@@ -170,6 +170,7 @@ type (
 	// Prometheus provides the prometheus configuration.
 	Prometheus struct {
 		EnableAnonymousAccess bool `envconfig:"DRONE_PROMETHEUS_ANONYMOUS_ACCESS" default:"false"`
+		EnableHTTPMetrics     bool `envconfig:"DRONE_PROMETHEUS_HTTP_METRICS" default:"false"`
 	}
 
 	// Redis provides the redis configuration.

cmd/drone-server/inject_server.go

@@ -60,10 +60,12 @@ var serverSet = wire.NewSet(
 
 // provideRouter is a Wire provider function that returns a
 // router that is serves the provided handlers.
-func provideRouter(api api.Server, web web.Server, rpcv1 rpcHandlerV1, rpcv2 rpcHandlerV2, healthz healthzHandler, metrics *metric.Server, pprof pprofHandler) *chi.Mux {
+func provideRouter(api api.Server, web web.Server, rpcv1 rpcHandlerV1, rpcv2 rpcHandlerV2, healthz healthzHandler, metrics *metric.Server, pprof pprofHandler, config config.Config) *chi.Mux {
 	r := chi.NewRouter()
-	m := chiprometheus.NewMiddleware("server")
-	r.Use(m)
+	if config.Prometheus.EnableHTTPMetrics {
+		m := chiprometheus.NewPatternMiddleware("server")
+		r.Use(m)
+	}
 	r.Mount("/healthz", healthz)
 	r.Mount("/metrics", metrics)
 	r.Mount("/api", api.Handler())

cmd/drone-server/wire_gen.go

@@ -1,7 +1,8 @@
 // Code generated by Wire. DO NOT EDIT.
 
-//go:generate wire
-//+build !wireinject
+//go:generate go run github.com/google/wire/cmd/wire
+//go:build !wireinject
+// +build !wireinject
 
 package main
 
@@ -113,7 +114,7 @@ func InitializeApplication(config2 config.Config) (application, error) {
 	mainHealthzHandler := provideHealthz()
 	metricServer := provideMetric(session, config2)
 	mainPprofHandler := providePprof(config2)
-	mux := provideRouter(server, webServer, mainRpcHandlerV1, mainRpcHandlerV2, mainHealthzHandler, metricServer, mainPprofHandler)
+	mux := provideRouter(server, webServer, mainRpcHandlerV1, mainRpcHandlerV2, mainHealthzHandler, metricServer, mainPprofHandler, config2)
 	serverServer := provideServer(mux, config2)
 	mainApplication := newApplication(cronScheduler, reaper, datadog, runner, serverServer, userStore)
 	return mainApplication, nil

handler/api/api.go

@@ -18,7 +18,6 @@ import (
 	"net/http"
 	"os"
 
-	chiprometheus "github.com/766b/chi-prometheus"
 	"github.com/drone/drone/core"
 	"github.com/drone/drone/handler/api/acl"
 	"github.com/drone/drone/handler/api/auth"
@@ -163,8 +162,6 @@ type Server struct {
 // Handler returns an http.Handler
 func (s Server) Handler() http.Handler {
 	r := chi.NewRouter()
-	m := chiprometheus.NewMiddleware("api")
-	r.Use(m)
 	r.Use(middleware.Recoverer)
 	r.Use(middleware.NoCache)
 	r.Use(logger.Middleware)

handler/web/web.go

@@ -25,7 +25,6 @@ import (
 	"github.com/drone/go-login/login"
 	"github.com/drone/go-scm/scm"
 
-	chiprometheus "github.com/766b/chi-prometheus"
 	"github.com/go-chi/chi"
 	"github.com/go-chi/chi/middleware"
 	"github.com/unrolled/secure"
@@ -95,8 +94,6 @@ type Server struct {
 // Handler returns an http.Handler
 func (s Server) Handler() http.Handler {
 	r := chi.NewRouter()
-	m := chiprometheus.NewMiddleware("web")
-	r.Use(m)
 	r.Use(middleware.Recoverer)
 	r.Use(middleware.NoCache)
 	r.Use(logger.Middleware)

operator/manager/rpc2/server.go

@@ -10,7 +10,6 @@ package rpc2
 import (
 	"net/http"
 
-	chiprometheus "github.com/766b/chi-prometheus"
 	"github.com/drone/drone/operator/manager"
 
 	"github.com/go-chi/chi"
@@ -25,8 +24,6 @@ type Server http.Handler
 // interaction with the build controller using the http transport.
 func NewServer(manager manager.BuildManager, secret string) Server {
 	r := chi.NewRouter()
-	m := chiprometheus.NewMiddleware("drone")
-	r.Use(m)
 	r.Use(middleware.Recoverer)
 	r.Use(middleware.NoCache)
 	r.Use(authorization(secret))