From c6a1761a7b8a9bf54fa7641f46b640b110de74a3 Mon Sep 17 00:00:00 2001
From: xiaoziv <xiaozheng@alumni.tongji.edu.cn>
Date: Thu, 11 Aug 2022 17:05:41 +0800
Subject: [PATCH] support tpls reload (#1104)

Co-authored-by: ziv <xiaozheng@tuya.com>
---
 src/server/engine/engine.go | 11 ++++++++++-
 src/server/engine/notify.go | 17 ++++++++++++++---
 src/server/server.go        |  4 ++++
 3 files changed, 28 insertions(+), 4 deletions(-)

diff --git a/src/server/engine/engine.go b/src/server/engine/engine.go
index 4d1141d6..d32e683c 100644
--- a/src/server/engine/engine.go
+++ b/src/server/engine/engine.go
@@ -4,13 +4,15 @@ import (
 	"context"
 	"time"
 
+	"github.com/toolkits/pkg/logger"
+
 	"github.com/didi/nightingale/v5/src/server/common/sender"
 	"github.com/didi/nightingale/v5/src/server/config"
 	promstat "github.com/didi/nightingale/v5/src/server/stat"
 )
 
 func Start(ctx context.Context) error {
-	err := initTpls()
+	err := reloadTpls()
 	if err != nil {
 		return err
 	}
@@ -28,6 +30,13 @@ func Start(ctx context.Context) error {
 	return nil
 }
 
+func Reload() {
+	err := reloadTpls()
+	if err != nil {
+		logger.Error("engine reload err:", err)
+	}
+}
+
 func reportQueueSize() {
 	for {
 		time.Sleep(time.Second)
diff --git a/src/server/engine/notify.go b/src/server/engine/notify.go
index 3328289f..213e5879 100644
--- a/src/server/engine/notify.go
+++ b/src/server/engine/notify.go
@@ -10,6 +10,7 @@ import (
 	"os/exec"
 	"path"
 	"strings"
+	"sync"
 	"time"
 
 	"github.com/pkg/errors"
@@ -29,9 +30,12 @@ import (
 	"github.com/didi/nightingale/v5/src/storage"
 )
 
-var tpls = make(map[string]*template.Template)
+var (
+	tpls   map[string]*template.Template
+	rwLock sync.RWMutex
+)
 
-func initTpls() error {
+func reloadTpls() error {
 	if config.C.Alerting.TemplatesDir == "" {
 		config.C.Alerting.TemplatesDir = path.Join(runner.Cwd, "etc", "template")
 	}
@@ -56,6 +60,7 @@ func initTpls() error {
 		return errors.New("no tpl files under " + config.C.Alerting.TemplatesDir)
 	}
 
+	tmpTpls := make(map[string]*template.Template)
 	for i := 0; i < len(tplFiles); i++ {
 		tplpath := path.Join(config.C.Alerting.TemplatesDir, tplFiles[i])
 
@@ -64,9 +69,12 @@ func initTpls() error {
 			return errors.WithMessage(err, "failed to parse tpl: "+tplpath)
 		}
 
-		tpls[tplFiles[i]] = tpl
+		tmpTpls[tplFiles[i]] = tpl
 	}
 
+	rwLock.Lock()
+	tpls = tmpTpls
+	rwLock.Unlock()
 	return nil
 }
 
@@ -78,6 +86,9 @@ type Notice struct {
 func genNotice(event *models.AlertCurEvent) Notice {
 	// build notice body with templates
 	ntpls := make(map[string]string)
+
+	rwLock.RLock()
+	defer rwLock.RUnlock()
 	for filename, tpl := range tpls {
 		var body bytes.Buffer
 		if err := tpl.Execute(&body, event); err != nil {
diff --git a/src/server/server.go b/src/server/server.go
index 7c9ddf83..d694a3c4 100644
--- a/src/server/server.go
+++ b/src/server/server.go
@@ -9,6 +9,7 @@ import (
 	"syscall"
 
 	"github.com/toolkits/pkg/i18n"
+	"github.com/toolkits/pkg/logger"
 
 	"github.com/didi/nightingale/v5/src/pkg/httpx"
 	"github.com/didi/nightingale/v5/src/pkg/logx"
@@ -75,6 +76,9 @@ EXIT:
 			break EXIT
 		case syscall.SIGHUP:
 			// reload configuration?
+			logger.Info("start reload configs")
+			engine.Reload()
+			logger.Info("reload configs finished")
 		default:
 			break EXIT
 		}