opm: always serve pprof endpoints

There's no substantial runtime cost to serving the endpoints by default,
and when things hit the fan you always need to query them in situ.

Signed-off-by: Steve Kuznetsov <[email protected]>

Author: stevekuznetsov

cmd/opm/serve/serve.go

@@ -80,14 +80,17 @@ will not be reflected in the served content.
 	cmd.Flags().BoolVar(&s.debug, "debug", false, "enable debug logging")
 	cmd.Flags().StringVarP(&s.terminationLog, "termination-log", "t", "/dev/termination-log", "path to a container termination log file")
 	cmd.Flags().StringVarP(&s.port, "port", "p", "50051", "port number to serve on")
-	cmd.Flags().StringVar(&s.pprofAddr, "pprof-addr", "", "address of startup profiling endpoint (addr:port format)")
+	cmd.Flags().StringVar(&s.pprofAddr, "pprof-addr", "localhost:6060", "address of startup profiling endpoint (addr:port format)")
 	cmd.Flags().StringVar(&s.cacheDir, "cache-dir", "", "if set, sync and persist server cache directory")
 	cmd.Flags().BoolVar(&s.cacheOnly, "cache-only", false, "sync the serve cache and exit without serving")
 	cmd.Flags().BoolVar(&s.cacheEnforceIntegrity, "cache-enforce-integrity", false, "exit with error if cache is not present or has been invalidated. (default: true when --cache-dir is set and --cache-only is false, false otherwise), ")
 	return cmd
 }
 
 func (s *serve) run(ctx context.Context) error {
+	if s.pprofAddr == "" {
+		s.logger.Fatal("--pprof-addr cannot be empty")
+	}
 	p := newProfilerInterface(s.pprofAddr, s.logger)
 	if err := p.startEndpoint(); err != nil {
 		return fmt.Errorf("could not start pprof endpoint: %v", err)
@@ -193,16 +196,7 @@ func newProfilerInterface(a string, log *logrus.Entry) *profilerInterface {
 	}
 }
 
-func (p *profilerInterface) isEnabled() bool {
-	return p.addr != ""
-}
-
 func (p *profilerInterface) startEndpoint() error {
-	// short-circuit if not enabled
-	if !p.isEnabled() {
-		return nil
-	}
-
 	mux := http.NewServeMux()
 	mux.HandleFunc("/debug/pprof/", endpoint.Index)
 	mux.HandleFunc("/debug/pprof/cmdline", endpoint.Cmdline)
@@ -235,11 +229,6 @@ func (p *profilerInterface) startEndpoint() error {
 }
 
 func (p *profilerInterface) startCpuProfileCache() error {
-	// short-circuit if not enabled
-	if !p.isEnabled() {
-		return nil
-	}
-
 	p.logger.Infof("start caching cpu profile data at %q", defaultCpuStartupPath)
 	if err := pprof.StartCPUProfile(&p.cache); err != nil {
 		return err
@@ -249,10 +238,6 @@ func (p *profilerInterface) startCpuProfileCache() error {
 }
 
 func (p *profilerInterface) stopCpuProfileCache() {
-	// short-circuit if not enabled
-	if !p.isEnabled() {
-		return
-	}
 	pprof.StopCPUProfile()
 	p.setCacheReady()
 	p.logger.Info("stopped caching cpu profile data")
@@ -266,9 +251,6 @@ func (p *profilerInterface) httpHandler(w http.ResponseWriter, r *http.Request)
 }
 
 func (p *profilerInterface) stopEndpoint(ctx context.Context) error {
-	if !p.isEnabled() {
-		return nil
-	}
 	if err := p.server.Shutdown(ctx); err != nil {
 		return err
 	}