概述

全鏈路灰度是基于流量標簽功能，在微服務整個調用鏈中進行統一的流量打標和治理，從而實現全鏈路灰度能力。本文介紹如何實現全鏈路灰度發布能力。

微服務調用關系

微服務架構中有三個服務，app1、app2、app3，調用關系如下圖，入口由Ingress網關做流量分發，要實現全鏈路灰度，預期是可以實現微服務之間只在在base版本內和test版本內調用，實現虛擬泳道。

前提條件

1. 開通云容器引擎。
2. 開通服務網格實例。

操作步驟

安裝ingress gateway

登錄控制臺，選擇對應的服務網格，進入網格頁面后，通過左邊欄的“網關”一欄選擇“入口網關”。

進入網關頁面后，選擇集群和命名空間后可以創建網關。

填入詳細的參數后，點確認即可。如圖：

部署應用

在云容器引擎集群內創建demo命名空間，部署base版本和test版本應用。

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.daliqc.cn/library/trace-demo:v1.0.0
        imagePullPolicy: IfNotPresent
        env:
        - name: version
          value: base
        - name: app
          value: app1
        - name: upstream_url
          value: "//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.daliqc.cn/library/trace-demo:v1.0.0
        imagePullPolicy: IfNotPresent
        env:
        - name: version
          value: base
        - name: app
          value: app2
        - name: upstream_url
          value: "//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.daliqc.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.daliqc.cn/library/trace-demo:v1.0.0
        imagePullPolicy: IfNotPresent
        env:
        - name: version
          value: test
        - name: app
          value: app1
        - name: upstream_url
          value: "//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.daliqc.cn/library/trace-demo:v1.0.0
        imagePullPolicy: IfNotPresent
        env:
        - name: version
          value: test
        - name: app
          value: app2
        - name: upstream_url
          value: "//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.daliqc.cn/library/trace-demo:v1.0.0
        imagePullPolicy: IfNotPresent
        env:
        - name: version
          value: test
        - name: app
          value: app3
        ports:
        - containerPort: 8000

關聯的Service資源：

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

創建泳道組

我們的demo應用使用trace-ctx-id作為鏈路追蹤的key，app1作為微服務的入口應用。

添加base和test泳道

確定網關的訪問入口地址，設置為GATEWAY_HOST環境變量，執行如下語句訪問：

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

可以看到訪問在兩個版本之間跳變，微服務之間的調用也是在版本間穿插進行，此時的全鏈路沒有統一的路由策略。

請求帶上x-csm-traffic-tag: base，同時指定請求級別的trace-ctx-id：

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

可以看到請求只在base版本之間調用：

修改頭部x-csm-traffic-tag: test，可以看到請求只在test版本之間調用：