当您需要在多个服务间实现全链路的灰度发布时，可以通过配置TrafficLabel来识别流量特征，将网关入口流量分为正常流量和灰度流量。灰度流量特征会在请求调用链经过的各个服务间进行传递，从而实现全链路灰度发布。本文介绍如何通过TrafficLabel实现微服务的全链路灰度发布。

前提条件

功能介绍

灰度发布有多种实现方式，例如基于ASM完成蓝绿和灰度发布。该灰度方式偏重于单个服务的发布，通过使用Istio原生提供的VirtualService标签路由和权重分流进行实现。某些场景下，仅限于两个服务间的灰度不能满足需求。

ASM基于流量打标和标签路由功能，提供全链路灰度功能，帮助您解决多个服务同时发布灰度版本的问题。当业务进行功能灰度验证时，将入口流量分为正常流量和灰度流量，对请求流量进行流量特征识别。若请求流量为灰度流量，则将请求灰度的应用服务。该场景不再是简单的按流量比例灰度分发到后端不同的版本，而且灰度流量特征会在请求调用链经过的各个服务间进行传递。更多信息，请参见流量标签TrafficLabel说明。

配置说明

您可以单击配置文件，直接下载部署示例及相关配置文件。示例中应用服务调用链路如下：

应用服务调用链路

本示例服务中的应用A在调用B时，已包含传播HTTP标头my-request-id的代码实现逻辑。更多信息，请参见配置文件中的src/mock-abc/go/main.go。

说明 如果您使用其他的应用示例，请确保在调用中包含传播HTTP标头的逻辑，后续的功能依赖于这个传播的HTTP标头。
展开查看应用Base版本的部署文件application-base.yaml
apiVersion: v1
kind: Service
metadata:
  name: mocka
  labels:
    app: mocka
    service: mocka
spec:
  ports:
  - port: 8000
    name: http
  selector:
    app: mocka
---
apiVersion: apps/v1
kind: Deployment
metadata:
  name: mocka-base
  labels:
    app: mocka
    version: base
spec:
  replicas: 1
  selector:
    matchLabels:
      app: mocka
      version: base
  template:
    metadata:
      labels:
        app: mocka
        version: base
    spec:
      containers:
      - name: default
        image: registry.cn-beijing.aliyuncs.com/aliacs-app-catalog/go-http-sample:1.0
        imagePullPolicy: Always
        env:
        - name: version
          value: base
        - name: app
          value: mocka
        - name: upstream_url
          value: "http://mockb:8000/"
        ports:
        - containerPort: 8000
---
apiVersion: v1
kind: Service
metadata:
  name: mockb
  labels:
    app: mockb
    service: mockb
spec:
  ports:
  - port: 8000
    name: http
  selector:
    app: mockb
---
apiVersion: apps/v1
kind: Deployment
metadata:
  name: mockb-base
  labels:
    app: mockb
    version: base
spec:
  replicas: 1
  selector:
    matchLabels:
      app: mockb
      version: base
  template:
    metadata:
      labels:
        app: mockb
        version: base
    spec:
      containers:
      - name: default
        image: registry.cn-beijing.aliyuncs.com/aliacs-app-catalog/go-http-sample:1.0
        imagePullPolicy: Always
        env:
        - name: version
          value: base
        - name: app
          value: mockb
        ports:
        - containerPort: 8000
展开查看应用Canary版本的部署文件application-canary.yaml
apiVersion: v1
kind: Service
metadata:
  name: mocka
  labels:
    app: mocka
    service: mocka
spec:
  ports:
  - port: 8000
    name: http
  selector:
    app: mocka
---
apiVersion: apps/v1
kind: Deployment
metadata:
  name: mocka-canary
  labels:
    app: mocka
    version: canary
spec:
  replicas: 1
  selector:
    matchLabels:
      app: mocka
      version: canary
  template:
    metadata:
      labels:
        app: mocka
        version: canary
    spec:
      containers:
      - name: default
        image: registry.cn-beijing.aliyuncs.com/aliacs-app-catalog/go-http-sample:1.0
        imagePullPolicy: Always
        env:
        - name: version
          value: canary
        - name: app
          value: mocka
        - name: upstream_url
          value: "http://mockb:8000/"
        ports:
        - containerPort: 8000
---
apiVersion: v1
kind: Service
metadata:
  name: mockb
  labels:
    app: mockb
    service: mockb
spec:
  ports:
  - port: 8000
    name: http
  selector:
    app: mockb
---
apiVersion: apps/v1
kind: Deployment
metadata:
  name: mockb-canary
  labels:
    app: mockb
    version: canary
spec:
  replicas: 1
  selector:
    matchLabels:
      app: mockb
      version: canary
  template:
    metadata:
      labels:
        app: mockb
        version: canary
    spec:
      containers:
      - name: default
        image: registry.cn-beijing.aliyuncs.com/aliacs-app-catalog/go-http-sample:1.0
        imagePullPolicy: Always
        env:
        - name: version
          value: canary
        - name: app
          value: mockb
        ports:
        - containerPort: 8000

步骤一：在ACK集群下部署示例应用

  1. 为目标命名空间（本示例为default）启用自动注入。具体操作，请参见启用自动注入。
  2. 使用ACK集群的KubeConfig，执行以下命令，部署示例应用。
    YAML文件，请参见配置说明。
    kubectl apply -n default -f application-base.yaml
kubectl apply -n default -f application-canary.yaml

步骤二：初始化路由规则配置

  1. 使用以下内容，创建routing.yaml文件。

    展开查看routing.yaml

    apiVersion: networking.istio.io/v1beta1
kind: Gateway
metadata:
  name: simple-gateway
spec:
  selector:
    istio: ingressgateway
  servers:
    - hosts:
        - "*"
      port:
        name: http
        number: 80
        protocol: HTTP
---
apiVersion: networking.istio.io/v1beta1
kind: DestinationRule
metadata:
  name: dr-mocka
spec:
  host: mocka
  trafficPolicy:
    loadBalancer:
      simple: ROUND_ROBIN
  subsets:
    - labels:
        version: base
      name: version-base
    - labels:
        version: canary
      name: version-canary
---
apiVersion: networking.istio.io/v1beta1
kind: DestinationRule
metadata:
  name: dr-mockb
spec:
  host: mockb
  trafficPolicy:
    loadBalancer:
      simple: ROUND_ROBIN
  subsets:
    - labels:
        version: base
      name: version-base
    - labels:
        version: canary
      name: version-canary
---
apiVersion: networking.istio.io/v1beta1
kind: VirtualService
metadata:
  name: vs-gateway-mocka
spec:
  gateways:
  - simple-gateway
  hosts:
    - "*"
  http:
  - route:
      - destination:
          host: mocka
---
apiVersion: networking.istio.io/v1beta1
kind: VirtualService
metadata:
  name: vs-mockb
spec:
  hosts:
    - mockb
  http:
    - route:
        - destination:
            host: mockb
  2. 使用ASM实例的KubeConfig，执行以下命令，配置路由。
    kubectl apply -n default -f routing.yaml
  3. 验证服务访问是否可以连通。
    1. 通过ASM控制台获取网关的公网IP。具体操作，请参见获取ASM网关地址。
    2. 执行以下命令，设置环境变量。
      xxxx为上一步获取的IP。
      export ASM_GATEWAY_IP=xxxx
    3. 执行以下命令，验证服务访问是否可以连通。
      for i in {1..200};  do curl   -H'my-asm-prefer-tag: version-base'  -H'my-request-id: x000'$i  http://${ASM_GATEWAY_IP}/; echo; sleep 1; done;
      预期输出：
      -> mocka(version: canary, ip: 172.17.0.129)-> mockb(version: base, ip: 172.17.0.70)
-> mocka(version: base, ip: 172.17.0.132)-> mockb(version: base, ip: 172.17.0.70)
-> mocka(version: base, ip: 172.17.0.132)-> mockb(version: canary, ip: 172.17.0.54)
-> mocka(version: canary, ip: 172.17.0.129)-> mockb(version: canary, ip: 172.17.0.54)
-> mocka(version: canary, ip: 172.17.0.129)-> mockb(version: base, ip: 172.17.0.70)
-> mocka(version: base, ip: 172.17.0.132)-> mockb(version: base, ip: 172.17.0.70)
-> mocka(version: canary, ip: 172.17.0.129)-> mockb(version: canary, ip: 172.17.0.54)
      预期输出表明从ASM入口网关到应用服务A，以及从应用A调用B的过程，负载均衡是随机的路由策略。 通过curl命令指定的my-asm-prefer-tag或者其他请求头都不会改变随机路由的策略。

步骤三：为示例应用设置流量标签

ASM支持通过TrafficLabel CRD设置流量标签，然后根据流量标签将流量路由到不同的工作负载。更多信息，请参见流量标签TrafficLabel说明。

  1. 使用以下内容，创建trafficlabel.yaml文件。
    apiVersion: istio.alibabacloud.com/v1
kind: TrafficLabel
metadata:
  name: trafficlabel-ns
  namespace: default
spec:
  rules:
  - labels:
    - name: asm-labels-sample
      valueFrom:
      - $getExternalInboundRequestHeader(my-asm-prefer-tag, my-request-id)
---
apiVersion: istio.alibabacloud.com/v1
kind: TrafficLabel
metadata:
  name: ingressgateway
  namespace: istio-system
spec:
  rules:
  - labels:
    - name: asm-labels-sample
      valueFrom:
      - $getInboundRequestHeader(my-asm-prefer-tag)
  workloadSelector:
    labels:
      istio: ingressgateway
    配置说明如下：
    • TrafficLabel trafficlabel-ns配置针对命名空间default下所有的应用服务生效，即示例中部署的mocka和mockb服务；TrafficLabel ingressgateway针对网关ingressgateway生效。
    • 用于区分版本的请求头为my-asm-prefer-tag，因此getExternalInboundRequestHeader中的第一个参数对应设置为my-asm-prefer-tag。请您根据实际情况进行修改。
    • 传播的HTTP标头为my-request-id，因此getExternalInboundRequestHeader中的第二个参数对应设置为my-request-id。请您根据实际情况进行修改。
  2. 使用ASM实例的KubeConfig，执行以下命令，部署TrafficLabel。
    kubectl apply -f trafficlabel.yaml

步骤四：配置标签路由规则

您可以通过配置标签路由规则，控制流量的走向。

一、验证服务提供侧的灰度

验证应用A→B的调用是否符合预期，其中包括流向A的灰度流量打到灰度版本，以及Base流量打到Base版本。

配置应用B的基于流量标签的路由规则后，流量示意图如下。验证服务提供侧的灰度
  1. 使用以下内容，创建vs-tf-mockb.yaml文件。
    apiVersion: networking.istio.io/v1beta1
kind: VirtualService
metadata:
  name: vs-mockb
spec:
  hosts:
    - mockb
  http:
    - route:
        - destination:
            host: mockb
            subset: $asm-labels-sample
  2. 执行以下命令，在A服务侧生效路由规则。
    kubectl apply -n default -f vs-tf-mockb.yaml
  3. 执行以下命令，验证流向A的灰度流量打到灰度版本。
    for i in {1..200};  do curl -H'my-asm-prefer-tag: version-canary'  -H'my-request-id: x000'$i  http://${ASM_GATEWAY_IP}/; echo; sleep 1; done;
    预期输出：
    -> mocka(version: canary, ip: 172.17.0.129)-> mockb(version: canary, ip: 172.17.0.54)
-> mocka(version: base, ip: 172.17.0.132)-> mockb(version: canary, ip: 172.17.0.54)
-> mocka(version: base, ip: 172.17.0.132)-> mockb(version: canary, ip: 172.17.0.54)
-> mocka(version: canary, ip: 172.17.0.129)-> mockb(version: canary, ip: 172.17.0.54)
-> mocka(version: canary, ip: 172.17.0.129)-> mockb(version: canary, ip: 172.17.0.54)
-> mocka(version: base, ip: 172.17.0.132)-> mockb(version: canary, ip: 172.17.0.54)
  4. 执行以下命令，验证流向A的Base流量打到Base版本。
    for i in {1..200};  do curl -H'my-asm-prefer-tag: version-base'  -H'my-request-id: x000'$i  http://${ASM_GATEWAY_IP}/; echo; sleep 1; done;
    预期输出：
    -> mocka(version: canary, ip: 172.17.0.129)-> mockb(version: base, ip: 172.17.0.70)
-> mocka(version: base, ip: 172.17.0.132)-> mockb(version: base, ip: 172.17.0.70)
-> mocka(version: base, ip: 172.17.0.132)-> mockb(version: base, ip: 172.17.0.70)
-> mocka(version: canary, ip: 172.17.0.129)-> mockb(version: base, ip: 172.17.0.70)
-> mocka(version: base, ip: 172.17.0.132)-> mockb(version: base, ip: 172.17.0.70)
-> mocka(version: canary, ip: 172.17.0.129)-> mockb(version: base, ip: 172.17.0.70)
-> mocka(version: canary, ip: 172.17.0.129)-> mockb(version: base, ip: 172.17.0.70)
-> mocka(version: base, ip: 172.17.0.132)-> mockb(version: base, ip: 172.17.0.70)
    预期输出表明入口流量访问A服务未流向指定版本。您需要配置A服务的基于流量标签的路由规则。具体操作，请参见下一步。

二、验证全链路灰度

配置A服务的TrafficLabel路由vs-tf-mocka.yaml，在ASM网关侧生效。预期结果为入口请求灰度流量打到A的灰度版本，Base流量打到A的Base版本，并传递到B服务。

配置应用A的基于流量标签的路由规则后，流量示意图如下。验证全链路灰度
  1. 使用以下示例，创建文件vs-tf-mocka.yaml。
    apiVersion: networking.istio.io/v1beta1
kind: VirtualService
metadata:
  name: vs-gateway-mocka
spec:
  gateways:
  - simple-gateway
  hosts:
    - "*"
  http:
  - route:
      - destination:
          host: mocka
          subset: $asm-labels-sample
  2. 执行以下命令，在ASM网关侧生效路由规则。
    kubectl apply -n default -f vs-tf-mocka.yaml
  3. 执行以下命令，验证入口请求灰度流量打到A的灰度版本。
    for i in {1..200};  do curl -H'my-asm-prefer-tag: version-canary'  -H'my-request-id: x000'$i  http://${ASM_GATEWAY_IP}/; echo; sleep 1; done;
    预期输出：
    -> mocka(version: canary, ip: 172.17.0.69)-> mockb(version: canary, ip: 172.17.0.130)
-> mocka(version: canary, ip: 172.17.0.69)-> mockb(version: canary, ip: 172.17.0.130)
-> mocka(version: canary, ip: 172.17.0.69)-> mockb(version: canary, ip: 172.17.0.130)
-> mocka(version: canary, ip: 172.17.0.69)-> mockb(version: canary, ip: 172.17.0.130)
-> mocka(version: canary, ip: 172.17.0.69)-> mockb(version: canary, ip: 172.17.0.130)
-> mocka(version: canary, ip: 172.17.0.69)-> mockb(version: canary, ip: 172.17.0.130)
-> mocka(version: canary, ip: 172.17.0.69)-> mockb(version: canary, ip: 172.17.0.130)
  4. 执行以下命令，验证Base流量打到A的Base版本，并传递到B服务。
    for i in {1..200};  do curl -H'my-asm-prefer-tag: version-base'  -H'my-request-id: x000'$i  http://${ASM_GATEWAY_IP}/; echo; sleep 1; done;
    预期输出：
    -> mocka(version: base, ip: 172.17.0.90)-> mockb(version: base, ip: 172.17.0.93)
-> mocka(version: base, ip: 172.17.0.90)-> mockb(version: base, ip: 172.17.0.93)
-> mocka(version: base, ip: 172.17.0.90)-> mockb(version: base, ip: 172.17.0.93)
-> mocka(version: base, ip: 172.17.0.90)-> mockb(version: base, ip: 172.17.0.93)
-> mocka(version: base, ip: 172.17.0.90)-> mockb(version: base, ip: 172.17.0.93)
-> mocka(version: base, ip: 172.17.0.90)-> mockb(version: base, ip: 172.17.0.93)
-> mocka(version: base, ip: 172.17.0.90)-> mockb(version: base, ip: 172.17.0.93)

三、验证路由权重

当在应用A上配置基于权重与基于流量标签的路由规则后，流量示意图如下。验证路由权重
  1. 使用以下内容，创建vs-tf-mocka-90-10.yaml文件。
    apiVersion: networking.istio.io/v1beta1
kind: VirtualService
metadata:
  name: vs-gateway-mocka
spec:
  gateways:
  - simple-gateway
  hosts:
    - "*"
  http:
  - route:
      - destination:
          host: mocka
          subset: version-base
        weight: 90
      - destination:
          host: mocka
          subset: $asm-labels-sample
        weight: 10
  2. 执行以下命令，在ASM网关侧生效路由规则。
    kubectl apply -n default -f vs-tf-mocka-90-10.yaml
  3. 执行以下命令，验证入口请求灰度流量打到应用A的版本。
    for i in {1..200};  do curl -H'my-asm-prefer-tag: version-canary'  -H'my-request-id: x000'$i  http://${ASM_GATEWAY_IP}/; echo; sleep 1; done;
    预期输出：
    -> mocka(version: base, ip: 172.17.0.90)-> mockb(version: canary, ip: 172.17.0.130)
-> mocka(version: base, ip: 172.17.0.90)-> mockb(version: canary, ip: 172.17.0.130)
-> mocka(version: base, ip: 172.17.0.90)-> mockb(version: canary, ip: 172.17.0.130)
-> mocka(version: base, ip: 172.17.0.90)-> mockb(version: canary, ip: 172.17.0.130)
-> mocka(version: base, ip: 172.17.0.90)-> mockb(version: canary, ip: 172.17.0.130)
-> mocka(version: base, ip: 172.17.0.90)-> mockb(version: canary, ip: 172.17.0.130)
-> mocka(version: base, ip: 172.17.0.90)-> mockb(version: canary, ip: 172.17.0.130)
-> mocka(version: base, ip: 172.17.0.90)-> mockb(version: canary, ip: 172.17.0.130)
-> mocka(version: base, ip: 172.17.0.90)-> mockb(version: canary, ip: 172.17.0.130)
-> mocka(version: canary, ip: 172.17.0.69)-> mockb(version: canary, ip: 172.17.0.130)
    由预期输出得到，入口请求灰度流量约90%左右流向应用A的Base版本，10%左右流向到Canary版本。在上述生效的路由规则中，90%的请求进入应用A的Base版本，剩下的10%请求按照指定的请求头my-asm-prefer-tag的值来决定去向，而请求命令中指定version-canary为请求头my-asm-prefer-tag的值，即这10%的请求将流向Canary版本。
  4. 执行以下命令，验证入口请求的Base版本流量全部转到应用A的Base版本。
    for i in {1..200};  do curl -H'my-asm-prefer-tag: version-base'  -H'my-request-id: x000'$i  http://${ASM_GATEWAY_IP}/; echo; sleep 1; done;
    预期输出：
    -> mocka(version: base, ip: 172.17.0.90)-> mockb(version: base, ip: 172.17.0.93)
-> mocka(version: base, ip: 172.17.0.90)-> mockb(version: base, ip: 172.17.0.93)
-> mocka(version: base, ip: 172.17.0.90)-> mockb(version: base, ip: 172.17.0.93)
-> mocka(version: base, ip: 172.17.0.90)-> mockb(version: base, ip: 172.17.0.93)
-> mocka(version: base, ip: 172.17.0.90)-> mockb(version: base, ip: 172.17.0.93)
-> mocka(version: base, ip: 172.17.0.90)-> mockb(version: base, ip: 172.17.0.93)
-> mocka(version: base, ip: 172.17.0.90)-> mockb(version: base, ip: 172.17.0.93)
-> mocka(version: base, ip: 172.17.0.90)-> mockb(version: base, ip: 172.17.0.93)
-> mocka(version: base, ip: 172.17.0.90)-> mockb(version: base, ip: 172.17.0.93)
-> mocka(version: base, ip: 172.17.0.90)-> mockb(version: base, ip: 172.17.0.93)
    上述生效的路由规则中，90%的请求进入Base版本，剩下的10%请求按照指定的请求头my-asm-prefer-tag的值来决定去向，而请求命令中指定version-base为请求头my-asm-prefer-tag的值，即这10%的请求将流向Base版本。