cmd: Make debug address optional

cmd/shell.go

@@ -288,23 +288,23 @@ func newStatsRegistry(addr string, logger blog.Logger) prometheus.Registerer {
 	}))
 
 	if addr == "" {
-		logger.Err("Debug listen address is not configured")
-		os.Exit(1)
-	}
-	logger.Infof("Debug server listening on %s", addr)
+		logger.Infof("No debug server specified")
+	} else {
+		logger.Infof("Debug server listening on %s", addr)
 
-	server := http.Server{
-		Addr:        addr,
-		Handler:     mux,
-		ReadTimeout: time.Minute,
-	}
-	go func() {
-		err := server.ListenAndServe()
-		if err != nil {
-			logger.Errf("unable to boot debug server on %s: %v", addr, err)
-			os.Exit(1)
+		server := http.Server{
+			Addr:        addr,
+			Handler:     mux,
+			ReadTimeout: time.Minute,
 		}
-	}()
+		go func() {
+			err := server.ListenAndServe()
+			if err != nil {
+				logger.Errf("unable to boot debug server on %s: %v", addr, err)
+				os.Exit(1)
+			}
+		}()
+	}
 	return registry
 }