概述

全链路灰度是基于流量标签功能，在微服务整个调用链中进行统一的流量打标和治理，从而实现全链路灰度能力。本文介绍如何实现全链路灰度发布能力。

微服务调用关系

微服务架构中有三个服务，app1、app2、app3，调用关系如下图，入口由Ingress网关做流量分发，要实现全链路灰度，预期是可以实现微服务之间只在在base版本内和test版本内调用，实现虚拟泳道。

前提条件

1. 开通云容器引擎。
2. 开通服务网格实例。

操作步骤

安装ingress gateway

登录控制台，选择对应的服务网格，进入网格页面后，通过左边栏的“网关”一栏选择“入口网关”。

进入网关页面后，选择集群和命名空间后可以创建网关。

填入详细的参数后，点确认即可。如图：

部署应用

在云容器引擎集群内创建demo命名空间，部署base版本和test版本应用。

apiVersion: apps/v1
kind: Deployment
metadata:
  name: app1-base
  namespace: demo
  labels:
    app: app1
    csm-traffic-tag: base
spec:
  replicas: 1
  selector:
    matchLabels:
      app: app1
      name: app1
      csm-traffic-tag: base
  template:
    metadata:
      labels:
        sidecar.istio.io/inject: "true"
        app: app1
        name: app1
        source: CCSE
        csm-traffic-tag: base
    spec:
      containers:
      - name: default
        image: registry-vpc-crs-huadong1.cnsp-internal.ctyun.cn/library/trace-demo:v1.0.0
        imagePullPolicy: IfNotPresent
        env:
        - name: version
          value: base
        - name: app
          value: app1
        - name: upstream_url
          value: "http://app2:8000/"
        ports:
        - containerPort: 8000
--

apiVersion: apps/v1
kind: Deployment
metadata:
  name: app2-base
  namespace: demo
  labels:
    app: app2
    csm-traffic-tag: base
spec:
  replicas: 1
  selector:
    matchLabels:
      app: app2
      name: app2
      csm-traffic-tag: base
  template:
    metadata:
      labels:
        sidecar.istio.io/inject: "true"
        app: app2
        name: app2
        source: CCSE
        csm-traffic-tag: base
    spec:
      containers:
      - name: default
        image: registry-vpc-crs-huadong1.cnsp-internal.ctyun.cn/library/trace-demo:v1.0.0
        imagePullPolicy: IfNotPresent
        env:
        - name: version
          value: base
        - name: app
          value: app2
        - name: upstream_url
          value: "http://app3:8000/"
        ports:
        - containerPort: 8000
--

apiVersion: apps/v1
kind: Deployment
metadata:
  name: app3-base
  namespace: demo
  labels:
    app: app3
    csm-traffic-tag: base
spec:
  replicas: 1
  selector:
    matchLabels:
      app: app3
      name: app3
      csm-traffic-tag: base
  template:
    metadata:
      labels:
        sidecar.istio.io/inject: "true"
        app: app3
        name: app3
        source: CCSE
        csm-traffic-tag: base
    spec:
      containers:
      - name: default
        image: registry-vpc-crs-huadong1.cnsp-internal.ctyun.cn/library/trace-demo:v1.0.0
        imagePullPolicy: IfNotPresent
        env:
        - name: version
          value: base
        - name: app
          value: app3
        ports:
        - containerPort: 8000

test版本：

apiVersion: apps/v1
kind: Deployment
metadata:
  name: app1-test 
  namespace: demo
  labels:
    app: app1
    csm-traffic-tag: test
spec:
  replicas: 1
  selector:
    matchLabels:
      app: app1
      name: app1
      csm-traffic-tag: test
  template:
    metadata:
      labels:
        sidecar.istio.io/inject: "true"
        app: app1
        name: app1
        source: CCSE
        csm-traffic-tag: test
    spec:
      containers:
      - name: default
        image: registry-vpc-crs-huadong1.cnsp-internal.ctyun.cn/library/trace-demo:v1.0.0
        imagePullPolicy: IfNotPresent
        env:
        - name: version
          value: test
        - name: app
          value: app1
        - name: upstream_url
          value: "http://app2:8000/"
        ports:
        - containerPort: 8000
--

apiVersion: apps/v1
kind: Deployment
metadata:
  name: app2-test
  namespace: demo
  labels:
    app: app2
    csm-traffic-tag: test
spec:
  replicas: 1
  selector:
    matchLabels:
      app: app2
      name: app2
      csm-traffic-tag: test
  template:
    metadata:
      labels:
        sidecar.istio.io/inject: "true"
        app: app2
        name: app2
        source: CCSE
        csm-traffic-tag: test
    spec:
      containers:
      - name: default
        image: registry-vpc-crs-huadong1.cnsp-internal.ctyun.cn/library/trace-demo:v1.0.0
        imagePullPolicy: IfNotPresent
        env:
        - name: version
          value: test
        - name: app
          value: app2
        - name: upstream_url
          value: "http://app3:8000/"
        ports:
        - containerPort: 8000

apiVersion: apps/v1
kind: Deployment
metadata:
  name: app3-test
  namespace: demo
  labels:
    app: app3
    csm-traffic-tag: test
spec:
  replicas: 1
  selector:
    matchLabels:
      app: app3
      name: app3
      csm-traffic-tag: test
  template:
    metadata:
      labels:
        sidecar.istio.io/inject: "true"
        app: app3
        name: app3
        source: CCSE
        csm-traffic-tag: test
    spec:
      containers:
      - name: default
        image: registry-vpc-crs-huadong1.cnsp-internal.ctyun.cn/library/trace-demo:v1.0.0
        imagePullPolicy: IfNotPresent
        env:
        - name: version
          value: test
        - name: app
          value: app3
        ports:
        - containerPort: 8000

关联的Service资源：

apiVersion: v1
kind: Service
metadata:
  name: app1
  labels:
    app: app1
    service: app1
    withServiceMesh: true
spec:
  ports:
  - port: 8000
    name: http
  selector:
    app: app1
---
apiVersion: v1
kind: Service
metadata:
  name: app2
  labels:
    app: app2
    service: app2
    withServiceMesh: true
spec:
  ports:
  - port: 8000
    name: http
  selector:
    app: app2
---
apiVersion: v1
kind: Service
metadata:
  name: app3
  labels:
    app: app3
    service: app3
    withServiceMesh: true
spec:
  ports:
  - port: 8000
    name: http
  selector:
    app: app3

创建泳道组

我们的demo应用使用trace-ctx-id作为链路追踪的key，app1作为微服务的入口应用。

添加base和test泳道

确定网关的访问入口地址，设置为GATEWAY_HOST环境变量，执行如下语句访问：

for i in {1..100};  do curl http://${GATEWAY_HOST}/; echo; sleep 1; done;

可以看到访问在两个版本之间跳变，微服务之间的调用也是在版本间穿插进行，此时的全链路没有统一的路由策略。

请求带上x-csm-traffic-tag: base，同时指定请求级别的trace-ctx-id：

for i in {1..200};  do curl -H "x-csm-traffic-tag: base"  -H "trace-ctx-id: trace-$i"  [http://${GATEWAY_HOST}](); echo; sleep 1; done;

可以看到请求只在base版本之间调用：

修改头部x-csm-traffic-tag: test，可以看到请求只在test版本之间调用：