add pprof handler

cmd/proxy/debug.go

@@ -0,0 +1,17 @@
+//go:build pprof
+
+package main
+
+import (
+	"flag"
+	"os"
+)
+
+func init() {
+	flag.BoolVar(&pprofEnabled, "pprof", true, "")
+
+	if v, ok := os.LookupEnv("SENTRY_DSN"); ok {
+		sentrydsn = v
+	}
+	flag.StringVar(&sentrydsn, "sentry", sentrydsn, "sentry dsn to report errors")
+}

cmd/proxy/main.go

@@ -4,6 +4,7 @@ import (
 	"flag"
 	"log/slog"
 	"net/http"
+	"net/http/pprof"
 	"os"
 	"path/filepath"
 	"time"
@@ -22,6 +23,7 @@ var (
 	configFilePath = "config.yaml"
 	logLevel       = "info"
 	sentrydsn      = ""
+	pprofEnabled   = false
 )
 
 func init() {
@@ -31,12 +33,8 @@ func init() {
 	if v, ok := os.LookupEnv("LOG_LEVEL"); ok {
 		logLevel = v
 	}
-	if v, ok := os.LookupEnv("SENTRY_DSN"); ok {
-		sentrydsn = v
-	}
 	flag.StringVar(&configFilePath, "config", configFilePath, "path to config file")
 	flag.StringVar(&logLevel, "log-level", logLevel, "log level. (trace, debug, info, warn, error)")
-	flag.StringVar(&sentrydsn, "sentry", sentrydsn, "sentry dsn to report errors")
 }
 
 func configFromFile(path string) (*cacheproxy.Config, error) {
@@ -124,6 +122,14 @@ func main() {
 
 	mux.HandleFunc("GET /", server.HandleRequestWithCache)
 
+	if pprofEnabled {
+		mux.HandleFunc("GET /debug/pprof/", pprof.Index)
+		mux.HandleFunc("GET /debug/pprof/cmdline", pprof.Cmdline)
+		mux.HandleFunc("GET /debug/pprof/profile", pprof.Profile)
+		mux.HandleFunc("GET /debug/pprof/symbol", pprof.Symbol)
+		mux.HandleFunc("GET /debug/pprof/trace", pprof.Trace)
+	}
+
 	slog.With("addr", ":8881").Info("serving app")
 	if err := http.ListenAndServe(":8881", middleware.Use(mux,
 		recover.Recover(),