[#886] Feature: 提供一种go plugin 告警通知方式 (#887)

* [#886] Feature: 提供一种go plugin 告警通知方式

* fix: 移除下层并发

etc/script/notify/Makefile

@@ -0,0 +1,9 @@
+
+.phony: all
+all: plugin
+
+.phony: plugin
+plugin:
+	export GOPROXY=http://goproxy.cn,direct
+	go build -buildmode=plugin -o notify.so notify.go
+

etc/script/notify/README.md

@@ -0,0 +1,35 @@
+通过go plugin模式处理告警通知
+---
+
+相比于调用py脚本方式，该方式一般无需考虑依赖问题
+
+### (1) 编写动态链接库逻辑
+
+```go
+package main
+
+type inter interface {
+	Descript() string
+	Notify([]byte)
+}
+
+// 0、Descript 可用于该插件在 server 中的描述
+// 1、在 Notify 方法中实现要处理的自定义逻辑
+```
+
+实现以上接口的 `struct` 实例即为合法 `plugin`
+
+### (2) 构建链接库
+
+参考 `notify.go` 实现方式，执行 `make` 后可以看到生成一个 `notify.so` 链接文件，放到 n9e 对应项目位置即可
+
+### (3) 更新 n9e 配置
+
+```text
+[Alerting.CallPlugin]
+Enable = false
+PluginPath = "./etc/script/notify.so"
+# 注意此处caller必须在notify.so中作为变量暴露
+Caller = "n9eCaller"
+```
+

etc/script/notify/notify.go

@@ -0,0 +1,45 @@
+package main
+
+import (
+	"fmt"
+	"time"
+
+	"github.com/tidwall/gjson"
+)
+
+// the caller can be called for alerting notify by complete this interface
+type inter interface {
+	Descript() string
+	Notify([]byte)
+}
+
+// N9E complete
+type N9EPlugin struct {
+	Name        string
+	Description string
+	BuildAt     string
+}
+
+func (n *N9EPlugin) Descript() string {
+	return fmt.Sprintf("%s: %s", n.Name, n.Description)
+}
+
+func (n *N9EPlugin) Notify(bs []byte) {
+	var channels = []string{
+		"dingtalk_robot_token",
+		"wecom_robot_token",
+		"feishu_robot_token",
+	}
+	for _, ch := range channels {
+		if ret := gjson.GetBytes(bs, ch); ret.Exists() {
+			fmt.Printf("do something...")
+		}
+	}
+}
+
+// will be loaded for alertingCall
+var n9eCaller = N9EPlugin{
+	Name:        "n9e",
+	Description: "演示告警通过动态链接库方式通知",
+	BuildAt:     time.Now().Local().Format("2006/01/02 15:04:05"),
+}

etc/server.conf

@@ -75,6 +75,12 @@ NotifyBuiltinEnable = true
 Enable = false
 ScriptPath = "./etc/script/notify.py"
 
+[Alerting.CallPlugin]
+Enable = false
+# use a plugin via `go build -buildmode=plugin -o notify.so`
+PluginPath = "./etc/script/notify.so"
+Caller = "n9eCaller"
+
 [Alerting.RedisPub]
 Enable = false
 # complete redis key: ${ChannelPrefix} + ${Cluster}
@@ -211,4 +217,4 @@ MaxIdleConnsPerHost = 100
 # KeepAlive = 30000
 # MaxConnsPerHost = 0
 # MaxIdleConns = 100
-# MaxIdleConnsPerHost = 100
+# MaxIdleConnsPerHost = 100

go.mod

@@ -23,7 +23,7 @@ require (
 	github.com/prometheus/client_golang v1.11.0
 	github.com/prometheus/common v0.26.0
 	github.com/prometheus/prometheus v2.5.0+incompatible
-	github.com/tidwall/gjson v1.14.0 // indirect
+	github.com/tidwall/gjson v1.14.0
 	github.com/toolkits/pkg v1.2.9
 	github.com/urfave/cli/v2 v2.3.0
 	golang.org/x/net v0.0.0-20210805182204-aaa1db679c0d // indirect
@@ -31,7 +31,7 @@ require (
 	google.golang.org/genproto v0.0.0-20211007155348-82e027067bd4 // indirect
 	google.golang.org/grpc v1.41.0 // indirect
 	gopkg.in/alexcesaro/quotedprintable.v3 v3.0.0-20150716171945-2caba252f4dc // indirect
-	gopkg.in/gomail.v2 v2.0.0-20160411212932-81ebce5c23df // indirect
+	gopkg.in/gomail.v2 v2.0.0-20160411212932-81ebce5c23df
 	gorm.io/driver/mysql v1.1.2
 	gorm.io/driver/postgres v1.1.1
 	gorm.io/gorm v1.21.15

src/server/config/config.go

@@ -139,6 +139,7 @@ type Alerting struct {
 	NotifyConcurrency   int
 	NotifyBuiltinEnable bool
 	CallScript          CallScript
+	CallPlugin          CallPlugin
 	RedisPub            RedisPub
 	Webhook             Webhook
 }
@@ -148,6 +149,12 @@ type CallScript struct {
 	ScriptPath string
 }
 
+type CallPlugin struct {
+	Enable     bool
+	PluginPath string
+	Caller     string
+}
+
 type RedisPub struct {
 	Enable        bool
 	ChannelPrefix string

src/server/engine/notify.go

@@ -9,6 +9,8 @@ import (
 	"net/http"
 	"os/exec"
 	"path"
+	"plugin"
+	"runtime"
 	"strings"
 	"time"
 
@@ -119,6 +121,8 @@ func alertingRedisPub(bs []byte) {
 func handleNotice(notice Notice, bs []byte) {
 	alertingCallScript(bs)
 
+	alertingCallPlugin(bs)
+
 	if !config.C.Alerting.NotifyBuiltinEnable {
 		return
 	}
@@ -396,3 +400,37 @@ func alertingCallScript(stdinBytes []byte) {
 
 	logger.Infof("event_notify: exec %s output: %s", fpath, buf.String())
 }
+
+type Notifier interface {
+	Descript() string
+	Notify([]byte)
+}
+
+// call notify.so via golang plugin build
+// ig. etc/script/notify/notify.so
+func alertingCallPlugin(stdinBytes []byte) {
+	if runtime.GOOS == "windows" {
+		logger.Errorf("call notify plugin on unsupported os: %s", runtime.GOOS)
+		return
+	}
+	if !config.C.Alerting.CallPlugin.Enable {
+		return
+	}
+	p, err := plugin.Open(config.C.Alerting.CallPlugin.PluginPath)
+	if err != nil {
+		logger.Errorf("failed to open notify plugin: %v", err)
+		return
+	}
+	caller, err := p.Lookup(config.C.Alerting.CallPlugin.Caller)
+	if err != nil {
+		logger.Errorf("failed to load caller: %v", err)
+		return
+	}
+	notifier, ok := caller.(Notifier)
+	if !ok {
+		logger.Errorf("notifier interface not implemented): %v", err)
+		return
+	}
+	notifier.Notify(stdinBytes)
+	logger.Debugf("alertingCallPlugin done. %s", notifier.Descript())
+}