Gin 框架:实现分布式日志追踪

原创
2021/11/18 02:14
阅读数 272

介绍

通过一个完整例子,在基于 Gin 框架中实现分布式日志追踪。

什么是 API 日志追踪?

一个 API 请求会跨多个微服务,我们希望通过一个唯一的 ID 检索到整个链路的日志。

我们将会使用 rk-boot 来启动 Gin 框架的微服务。

请访问如下地址获取完整教程:

安装

go get github.com/rookie-ninja/rk-boot
go get github.com/rookie-ninja/rk-gin

快速开始

我们会创建 /v1/greeter API 进行验证,同时开启 logging, meta 和 tracing 中间件以达到目的。

1. 创建 bootA.yaml & serverA.go

ServerA 监听 1949 端口,并且发送请求给 ServerB。

我们通过 rkginctx.InjectSpanToNewContext() 方法把 Tracing 信息注入到 Context 中,发送给 ServerB。

---
gin:
  - name: greeter                   # Required
    port: 1949                      # Required
    enabled: true                   # Required
    interceptors:
      loggingZap:
        enabled: true               # Optional, enable logging interceptor
      meta:
        enabled: true               # Optional, enable meta interceptor
      tracingTelemetry:
        enabled: true               # Optional, enable tracing interceptor
// Copyright (c) 2021 rookie-ninja
//
// Use of this source code is governed by an Apache-style
// license that can be found in the LICENSE file.
package main

import (
	"context"
	"github.com/gin-gonic/gin"
	"github.com/rookie-ninja/rk-boot"
	"github.com/rookie-ninja/rk-gin/boot"
	"github.com/rookie-ninja/rk-gin/interceptor/context"
	"net/http"
)

// Application entrance.
func main() {
	// Create a new boot instance.
	boot := rkboot.NewBoot(rkboot.WithBootConfigPath("bootA.yaml"))

	// Register handler
	boot.GetEntry("greeter").(*rkgin.GinEntry).Router.GET("/v1/greeter", GreeterA)

	// Bootstrap
	boot.Bootstrap(context.Background())

	// Wait for shutdown sig
	boot.WaitForShutdownSig(context.Background())
}

// GreeterA will add trace info into context and call serverB
func GreeterA(ctx *gin.Context) {
	// Call serverB at 2008
	req, _ := http.NewRequest(http.MethodGet, "http://localhost:2008/v1/greeter", nil)

	// Inject current trace information into context
	rkginctx.InjectSpanToHttpRequest(ctx, req)

	// Call server
	http.DefaultClient.Do(req)
	
	// Respond to request
	ctx.String(http.StatusOK, "Hello from serverA!")
}

2. 创建 bootB.yaml & serverB.go

ServerB 监听 2008 端口。

---
gin:
  - name: greeter                   # Required
    port: 2008                      # Required
    enabled: true                   # Required
    interceptors:
      loggingZap:
        enabled: true               # Optional, enable logging interceptor
      meta:
        enabled: true               # Optional, enable meta interceptor
      tracingTelemetry:
        enabled: true               # Optional, enable tracing interceptor
// Copyright (c) 2021 rookie-ninja
//
// Use of this source code is governed by an Apache-style
// license that can be found in the LICENSE file.
package main

import (
	"context"
	"github.com/gin-gonic/gin"
	"github.com/rookie-ninja/rk-boot"
	"github.com/rookie-ninja/rk-gin/boot"
	"net/http"
)

// Application entrance.
func main() {
	// Create a new boot instance.
	boot := rkboot.NewBoot(rkboot.WithBootConfigPath("bootB.yaml"))

	// Register handler
	boot.GetEntry("greeter").(*rkgin.GinEntry).Router.GET("/v1/greeter", GreeterB)

	// Bootstrap
	boot.Bootstrap(context.Background())

	// Wait for shutdown sig
	boot.WaitForShutdownSig(context.Background())
}

// GreeterB receive request from serverA and respond.
func GreeterB(ctx *gin.Context) {
	ctx.String(http.StatusOK, "Hello from serverB!")
}

3. 文件夹结构

.
├── bootA.yaml
├── bootB.yaml
├── go.mod
├── go.sum
├── serverA.go
└── serverB.go

0 directories, 6 files

4. 启动 ServerA & ServerB

$ go run serverA.go
$ go run serverB.go

5. 往 ServerA 发送请求

$ curl localhost:1949/v1/greeter
Hello from serverA!

6. 验证日志

两个服务的日志中,会有同样的 traceId,不同的 requestId。

我们可以通过 grep traceId 来追踪 RPC。

  • ServerA
------------------------------------------------------------------------
endTime=2021-11-18T01:29:56.698997+08:00
...
ids={"eventId":"f5878390-1a5a-4bb9-8b39-bf4261864c0f","requestId":"f5878390-1a5a-4bb9-8b39-bf4261864c0f","traceId":"b2d70ab9f8207ef4a9f0c3fb1be5c22c"}
...
operation=/v1/greeter
resCode=200
eventStatus=Ended
EOE
  • ServerB
------------------------------------------------------------------------
endTime=2021-11-18T01:29:56.698606+08:00
...
ids={"eventId":"273c97d2-e11a-46f5-a044-bb9c0cf64540","requestId":"273c97d2-e11a-46f5-a044-bb9c0cf64540","traceId":"b2d70ab9f8207ef4a9f0c3fb1be5c22c"}
...
operation=/v1/greeter
resCode=200
eventStatus=Ended
EOE

概念

当我们没有使用例如 jaeger 调用链服务的时候,我们希望通过日志来追踪分布式系统里的 RPC 请求。

rk-boot 的中间件会通过 openTelemetry 库来向日志写入 traceId 来追踪 RPC。

当启动了日志中间件,原数据中间件,调用链中间件的时候,中间件会往日志里写入如下三种 ID。

EventId

当启动了日志中间件,EventId 会自动生成。

---
gin:
  - name: greeter                   # Required
    port: 1949                      # Required
    enabled: true                   # Required
    interceptors:
      loggingZap:
        enabled: true
------------------------------------------------------------------------
...
ids={"eventId":"cd617f0c-2d93-45e1-bef0-95c89972530d"}
...

RequestId

当启动了日志中间件和原数据中间件,RequestId 和 EventId 会自动生成,并且这两个 ID 会一致。

---
gin:
  - name: greeter                   # Required
    port: 1949                      # Required
    enabled: true                   # Required
    interceptors:
      loggingZap:
        enabled: true
      meta:
        enabled: true
------------------------------------------------------------------------
...
ids={"eventId":"8226ba9b-424e-4e19-ba63-d37ca69028b3","requestId":"8226ba9b-424e-4e19-ba63-d37ca69028b3"}
...

即使用户覆盖了 RequestId,EventId 也会保持一致。

rkginctx.AddHeaderToClient(ctx, rkginctx.RequestIdKey, "overridden-request-id")
------------------------------------------------------------------------
...
ids={"eventId":"overridden-request-id","requestId":"overridden-request-id"}
...

TraceId

当启动了调用链中间件,traceId 会自动生成。

---
gin:
  - name: greeter                   # Required
    port: 1949                      # Required
    enabled: true                   # Required
    interceptors:
      loggingZap:
        enabled: true
      meta:
        enabled: true
      tracingTelemetry:
        enabled: true
------------------------------------------------------------------------
...
ids={"eventId":"dd19cf9a-c7be-486c-b29d-7af777a78ebe","requestId":"dd19cf9a-c7be-486c-b29d-7af777a78ebe","traceId":"316a7b475ff500a76bfcd6147036951c"}
...
展开阅读全文
0
0 收藏
分享
加载中
更多评论
打赏
0 评论
0 收藏
0
分享
返回顶部
顶部