From ccea62a7622dd7d1ecdb5dc8836947b8517c89e7 Mon Sep 17 00:00:00 2001
From: Anton <m@antonz.org>
Date: Sun, 10 Nov 2024 17:14:27 +0500
Subject: [PATCH] server: enable debugging

---
 cmd/main.go                    | 28 +++++++++++++++++++++-------
 internal/server/router.go      | 12 ++++++++++++
 internal/server/server.go      |  4 ++--
 internal/server/server_test.go |  2 +-
 4 files changed, 36 insertions(+), 10 deletions(-)

diff --git a/cmd/main.go b/cmd/main.go
index b5964b5..5101d41 100644
--- a/cmd/main.go
+++ b/cmd/main.go
@@ -22,24 +22,37 @@ var (
 
 // startServer starts the HTTP API sandbox server.
 func startServer(port int) *server.Server {
+	const host = "" // listen on all interfaces
 	logx.Log("codapi %s, commit %s, built at %s", version, commit, date)
-	logx.Log("listening on port %d...", port)
+	logx.Log("listening on 0.0.0.0:%d...", port)
 	router := server.NewRouter()
-	srv := server.NewServer(port, router)
+	srv := server.NewServer(host, port, router)
+	srv.Start()
+	return srv
+}
+
+// startDebug servers the debug handlers.
+func startDebug(port int) *server.Server {
+	const host = "localhost"
+	logx.Log("debugging on localhost:%d...", port)
+	router := server.NewDebug()
+	srv := server.NewServer(host, port, router)
 	srv.Start()
 	return srv
 }
 
 // listenSignals listens for termination signals
 // and performs graceful shutdown.
-func listenSignals(srv *server.Server) {
+func listenSignals(servers []*server.Server) {
 	sigs := make(chan os.Signal, 1)
 	signal.Notify(sigs, syscall.SIGINT, syscall.SIGTERM)
 	<-sigs
 	logx.Log("stopping...")
-	err := srv.Stop()
-	if err != nil {
-		logx.Log("failed to stop: %v", err)
+	for _, srv := range servers {
+		err := srv.Stop()
+		if err != nil {
+			logx.Log("failed to stop: %v", err)
+		}
 	}
 }
 
@@ -65,5 +78,6 @@ func main() {
 	logx.Log("boxes: %v", cfg.BoxNames())
 	logx.Log("commands: %v", cfg.CommandNames())
 
-	listenSignals(srv)
+	debug := startDebug(6060)
+	listenSignals([]*server.Server{srv, debug})
 }
diff --git a/internal/server/router.go b/internal/server/router.go
index ae5e776..95c4817 100644
--- a/internal/server/router.go
+++ b/internal/server/router.go
@@ -5,6 +5,7 @@ import (
 	"errors"
 	"fmt"
 	"net/http"
+	"net/http/pprof"
 
 	"github.com/nalgeon/codapi/internal/engine"
 	"github.com/nalgeon/codapi/internal/logx"
@@ -19,6 +20,17 @@ func NewRouter() http.Handler {
 	return mux
 }
 
+// NewDebug creates HTTP routes for debugging.
+func NewDebug() http.Handler {
+	mux := http.NewServeMux()
+	mux.HandleFunc("/debug/pprof/", pprof.Index)
+	mux.HandleFunc("/debug/pprof/cmdline", pprof.Cmdline)
+	mux.HandleFunc("/debug/pprof/profile", pprof.Profile)
+	mux.HandleFunc("/debug/pprof/symbol", pprof.Symbol)
+	mux.HandleFunc("/debug/pprof/trace", pprof.Trace)
+	return mux
+}
+
 // exec runs a sandbox command on the supplied code.
 func exec(w http.ResponseWriter, r *http.Request) {
 	// only POST is allowed
diff --git a/internal/server/server.go b/internal/server/server.go
index b377871..5bd1b7e 100644
--- a/internal/server/server.go
+++ b/internal/server/server.go
@@ -21,8 +21,8 @@ type Server struct {
 }
 
 // NewServer creates a new Server.
-func NewServer(port int, handler http.Handler) *Server {
-	addr := fmt.Sprintf(":%d", port)
+func NewServer(host string, port int, handler http.Handler) *Server {
+	addr := fmt.Sprintf("%s:%d", host, port)
 	return &Server{
 		srv: &http.Server{Addr: addr, Handler: handler},
 		wg:  &sync.WaitGroup{},
diff --git a/internal/server/server_test.go b/internal/server/server_test.go
index 0e4c5d8..1bdd0d7 100644
--- a/internal/server/server_test.go
+++ b/internal/server/server_test.go
@@ -10,7 +10,7 @@ func TestServer(t *testing.T) {
 		w.WriteHeader(http.StatusOK)
 	})
 
-	srv := NewServer(8585, handler)
+	srv := NewServer("", 8585, handler)
 	if srv.srv.Addr != ":8585" {
 		t.Fatalf("NewServer: expected port :8585 got %s", srv.srv.Addr)
 	}