概述

本文介绍在使用消息队列（RocketMQ）这种异步场景下，可以在不修改业务代码的情况下，实现异步场景的灰度，从而实现全链路灰度。本文介绍基于消息队列RocketMQ实现全链路灰度。

背景介绍

在大多数业务场景中对于消息的灰度并没有RPC调用那么严格，但是当全链路灰度调用中涉及到消息消费时，如果消息消费没有按照全链路流量规则路由，则会导致通过消息产生的流量逃逸，从而破坏全链路规则，导致出现一些不符合预期的情况。

如下图所示，本文分别部署网关、app-a、app-a-gray、app-b、app-b-gray、app-c、app-c-gray以及RocketMQ，模拟一个真实的全链路灰度场景。

通过网关调用app-a应用的接口，当满足路由规则后，灰度流量会被路由到app-a-gray，app-a-gray又会调用app-b-gray，随后由app-b-gray发送灰度消息，app-c-gray将会收到灰度消息，而app-c不会收到灰度消息。

图片247.png

前提条件

用户已开通微服务治理中心企业版。
用户已开通云容器引擎。
用户已部署RocketMQ，且RocketMQ版本在4.5.0以上，broker.conf中已配置enablePropertyFilter=true。

部署Demo应用

准备自建入口网关msgc-zuul，准备应用msgc-app-a，msgc-app-b和msgc-app-c。调用过程是msgc-app-a –> msgc-app-b -> msgc-app-c。

步骤1：在云容器引擎中安装微服务治理插件：

登录“云容器引擎”控制台。
在左侧菜单栏选择“集群”，点击目标集群。
在集群管理页面点击“插件”-“插件市场”，选择“cubems”插件安装。

步骤2：为应用开启微服务治理能力：

登录“云容器引擎”控制台。
左侧菜单栏选择“集群”，点击目标集群。
在集群管理页面点击“工作负载”-“无状态”，选择目标命名空间。

在Deployment列表页选择指定Deployment，并点击“全量替换”，进入Deployment编辑页。
在Deployment编辑页点击“显示高级设置”，新增“Pod标签”: mseCubeMsAutoEnable:on。

在发布应用时，配置指定环境变量，可指定注入微服务治理中心的应用名、命名空间和标签等信息。

环境变量配置如下：

环境变量名	环境变量值
MSE_APP_NAME	接入到微服务治理中心的应用名。
MSE_SERVICE_TAG	应用标签信息，如灰度应用可配置gray。
MSE_NAMESPACE（选填）	接入到微服务治理中心的命名空间，默认为：default。

完成编辑后点击“提交”，重新发布容器即可接入。

app-a应用的配置

基线：

apiVersion: "apps/v1"
kind: "Deployment"
metadata:
  name: "app-a"
namespace: "default"
spec:
  progressDeadlineSeconds: 600
  replicas: 1
  revisionHistoryLimit: 10
  selector:
    matchLabels:
      name: "app-a"
  template:
    metadata:
      labels:
        mseCubeMsAutoEnable: "on"
        name: "app-a"
    spec:
      containers:
      - env:
        - name: "MSE_APP_NAME"
          value: "app-a"
	image: "镜像仓库域名/xxx/app-a:latest"
        imagePullPolicy: "Always"
        name: "app-a"
        ports:
        - containerPort: 26160
        livenessProbe:
          tcpSocket:
            port: 26160
          initialDelaySeconds: 10
          periodSeconds: 30
        resources:
          limits:
            cpu: "1"
            memory: "1Gi"
          requests:
            cpu: "1"
            memory: "1Gi"

灰度：

apiVersion: "apps/v1"
kind: "Deployment"
metadata:
  name: "app-a"
namespace: "default"
spec:
  progressDeadlineSeconds: 600
  replicas: 1
  revisionHistoryLimit: 10
  selector:
    matchLabels:
      name: "app-a"
  template:
    metadata:
      labels:
        mseCubeMsAutoEnable: "on"
        name: "app-a"
    spec:
      containers:
      - env:
        - name: "MSE_APP_NAME"
          value: "app-a"
	- name: "MSE_SERVICE_TAG"
          value: "gray"
	image: "镜像仓库域名/xxx/app-a:latest"
        imagePullPolicy: "Always"
        name: "app-a"
        ports:
        - containerPort: 26160
        livenessProbe:
          tcpSocket:
            port: 26160
          initialDelaySeconds: 10
          periodSeconds: 30
        resources:
          limits:
            cpu: "1"
            memory: "1Gi"
          requests:
            cpu: "1"
            memory: "1Gi"

app-b应用的配置

基线：

apiVersion: "apps/v1"
kind: "Deployment"
metadata:
  name: "app-b"
namespace: "default"
spec:
  progressDeadlineSeconds: 600
  replicas: 1
  revisionHistoryLimit: 10
  selector:
    matchLabels:
      name: "app-b"
  template:
    metadata:
      labels:
        mseCubeMsAutoEnable: "on"
        name: "app-b"
    spec:
      containers:
      - env:
        - name: "MSE_APP_NAME"
          value: "app-b"
	image: "镜像仓库域名/xxx/app-b:latest"
        imagePullPolicy: "Always"
        name: "app-b"
        ports:
        - containerPort: 26160
        livenessProbe:
          tcpSocket:
            port: 26160
          initialDelaySeconds: 10
          periodSeconds: 30
        resources:
          limits:
            cpu: "1"
            memory: "1Gi"
          requests:
            cpu: "1"
            memory: "1Gi"

灰度：

apiVersion: "apps/v1"
kind: "Deployment"
metadata:
  name: "app-b"
namespace: "default"
spec:
  progressDeadlineSeconds: 600
  replicas: 1
  revisionHistoryLimit: 10
  selector:
    matchLabels:
      name: "app-b"
  template:
    metadata:
      labels:
        mseCubeMsAutoEnable: "on"
        name: "app-b"
    spec:
      containers:
      - env:
        - name: "MSE_APP_NAME"
          value: "app-b"
	- name: "MSE_SERVICE_TAG"
          value: "gray"
	image: "镜像仓库域名/xxx/app-b:latest"
        imagePullPolicy: "Always"
        name: "app-b"
        ports:
        - containerPort: 26160
        livenessProbe:
          tcpSocket:
            port: 26160
          initialDelaySeconds: 10
          periodSeconds: 30
        resources:
          limits:
            cpu: "1"
            memory: "1Gi"
          requests:
            cpu: "1"
            memory: "1Gi"

app-c应用的配置

基线：

apiVersion: "apps/v1"
kind: "Deployment"
metadata:
  name: "app-c"
namespace: "default"
spec:
  progressDeadlineSeconds: 600
  replicas: 1
  revisionHistoryLimit: 10
  selector:
    matchLabels:
      name: "app-c"
  template:
    metadata:
      labels:
        mseCubeMsAutoEnable: "on"
        name: "app-c"
    spec:
      containers:
      - env:
        - name: "MSE_APP_NAME"
          value: "app-c"
	image: "镜像仓库域名/xxx/app-c:latest"
        imagePullPolicy: "Always"
        name: "app-c"
        ports:
        - containerPort: 26160
        livenessProbe:
          tcpSocket:
            port: 26160
          initialDelaySeconds: 10
          periodSeconds: 30
        resources:
          limits:
            cpu: "1"
            memory: "1Gi"
          requests:
            cpu: "1"
            memory: "1Gi"

灰度：

apiVersion: "apps/v1"
kind: "Deployment"
metadata:
  name: "app-c"
namespace: "default"
spec:
  progressDeadlineSeconds: 600
  replicas: 1
  revisionHistoryLimit: 10
  selector:
    matchLabels:
      name: "app-c"
  template:
    metadata:
      labels:
        mseCubeMsAutoEnable: "on"
        name: "app-c"
    spec:
      containers:
      - env:
        - name: "MSE_APP_NAME"
          value: "app-c"
	- name: "MSE_SERVICE_TAG"
          value: "gray"
	image: "镜像仓库域名/xxx/app-c:latest"
        imagePullPolicy: "Always"
        name: "app-c"
        ports:
        - containerPort: 26160
        livenessProbe:
          tcpSocket:
            port: 26160
          initialDelaySeconds: 10
          periodSeconds: 30
        resources:
          limits:
            cpu: "1"
            memory: "1Gi"
          requests:
            cpu: "1"
            memory: "1Gi"

zuul应用的配置：

apiVersion: "apps/v1"
kind: "Deployment"
metadata:
  name: "zuul"
namespace: "default"
spec:
  progressDeadlineSeconds: 600
  replicas: 1
  revisionHistoryLimit: 10
  selector:
    matchLabels:
      name: "zuul"
  template:
    metadata:
      labels:
        mseCubeMsAutoEnable: "on"
        name: "zuul"
    spec:
      containers:
      - env:
        - name: "MSE_APP_NAME"
          value: "zuul"
	image: "镜像仓库域名/xxx/zuul:latest"
        imagePullPolicy: "Always"
        name: "zuul"
        ports:
        - containerPort: 26160
        livenessProbe:
          tcpSocket:
            port: 26160
          initialDelaySeconds: 10
          periodSeconds: 30
        resources:
          limits:
            cpu: "1"
            memory: "1Gi"
          requests:
            cpu: "1"
            memory: "1Gi"