概述

您可以基于微服务治理在不修改任何业务代码的情况下，实现全链路灰度的流量控制。本文介绍用户如何通过自建网关实现全链路灰度功能。

前提条件

1、用户已开通微服务治理中心企业版。

2、用户已开通云容器引擎。

背景信息

在微服务架构下，一次需求可能会同时修改多个微服务应用。在发布应用时，通常将这些应用划分为同一个分组，使灰度流量始终在灰度应用中流转。当上游有灰度流量时，会通过引流的方式将灰度流量引导至灰度分组，在此次链路调用过程中，如果存在一些微服务没有灰度环境，那这些请求在下游时依然能回到灰度环境中，以此实现全链路灰度。

通过使用微服务治理中心，可以在不修改业务代码的情况下，轻松实现全链路灰度。本文介绍如何通过自建网关实现全链路灰度。

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：在云容器引擎集群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"