Kubernetes 使用Nginx-Ingress实现蓝绿发布/金丝雀发布/AB测试

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mb5ff5933087b38 2021-03-08 09:42:00

文章标签 nginx 权重优先级 4s 后端服务 文章分类 Nginx 服务器

背景介绍

某些情况下，我们在使用Kubernetes作为业务应用的云平台，想要实现应用的蓝绿部署用来迭代应用版本，用lstio太重太复杂，而且它本身定位于流控和网格治理；Ingress-Nginx在0.21版本引入了Canary功能，可以为网关入口配置多个版本的应用程序，使用annotation来控制多个后端服务的流量分配

Ingress-Nginx-Annotation Canary 功能介绍

如果想启用Canary功能，要先设置nginx.ingress.kubernetes.io/canary: "true"，然后可以启用以下注释来配置Canary

nginx.ingress.kubernetes.io/canary-weight 请求到Canary ingress中指定的服务的请求百分比，值为0-100的整数，根据设置的值来决定大概有百分之多少的流量会分配Canary Ingress中指定的后端s服务
nginx.ingress.kubernetes.io/canary-by-header 基于request header 的流量切分，适用于灰度发布或者A/B测试，当设定的hearder值为always是，请求流量会被一直分配到Canary入口，当hearder值被设置为never时，请求流量不会分配到Canary入口，对于其他hearder值，将忽略，并通过优先级将请求流量分配到其他规则
nginx.ingress.kubernetes.io/canary-by-header-value 这个配置要和nginx.ingress.kubernetes.io/canary-by-header 一起使用，当请求中的hearder key和value 和nginx.ingress.kubernetes.io/canary-by-header nginx.ingress.kubernetes.io/canary-by-header-value匹配时，请求流量会被分配到Canary Ingress入口，对于其他任何hearder值，将忽略，并通过优先级将请求流量分配到其他规则
nginx.ingress.kubernetes.io/canary-by-cookie 这个配置是基于cookie的流量切分，也适用于灰度发布或者A/B测试，当cookie值设置为always时，请求流量将被路由到Canary Ingress入口，当cookie值设置为never时，请求流量将不会路由到Canary入口，对于其他值，将忽略，并通过优先级将请求流量分配到其他规则

金丝雀规则按优先顺序进行如下排序：canary-by-header - > canary-by-cookie - > canary-weight

1.基于权重的小规模版本测试

v1版本编排文件

apiVersion: extensions/v1beta1
kind: Ingress
metadata:
  annotations:
    kubernetes.io/ingress.class: nginx
  labels:
    app: echoserverv1
  name: echoserverv1
  namespace: echoserver
spec:
  rules:
  - host: echo.chulinx.com
    http:
      paths:
      - backend:
          serviceName: echoserverv1
          servicePort: 8080
        path: /
---
kind: Service
apiVersion: v1
metadata:
  name:  echoserverv1
  namespace: echoserver
spec:
  selector:
    name:  echoserverv1
  type:  ClusterIP
  ports:
  - name:  echoserverv1
    port:  8080
    targetPort:  8080
---
apiVersion: extensions/v1beta1
kind: Deployment
metadata:
  name:  echoserverv1
  namespace: echoserver
  labels:
    name:  echoserverv1
spec:
  template:
    metadata:
      labels:
        name:  echoserverv1
    spec:
      containers:
      - image:  mirrorgooglecontainers/echoserver:1.10
        name:  echoserverv1 
        ports:
        - containerPort:  8080
          name:  echoserverv1
复制代码

查看v1版本创建的资源

$ [K8sSj] kubectl get pod,service,ingress -n echoserver
NAME                                READY   STATUS    RESTARTS   AGE
pod/echoserverv1-657b966cb5-7grqs   1/1     Running   0          24h

NAME                   TYPE        CLUSTER-IP    EXTERNAL-IP   PORT(S)    AGE
service/echoserverv1   ClusterIP   10.99.68.72   <none>        8080/TCP   24h

NAME                              HOSTS              ADDRESS   PORTS   AGE
ingress.extensions/echoserverv1   echo.chulinx.com             80      24h
复制代码

访问v1的服务,可以看到10个请求都是访问到一个pod上也就是v1版本的服务

$ [K8sSj] for i in `seq 10`;do curl -s echo.chulinx.com|grep Hostname;done
Hostname: echoserverv1-657b966cb5-7grqs
Hostname: echoserverv1-657b966cb5-7grqs
Hostname: echoserverv1-657b966cb5-7grqs
Hostname: echoserverv1-657b966cb5-7grqs
Hostname: echoserverv1-657b966cb5-7grqs
Hostname: echoserverv1-657b966cb5-7grqs
Hostname: echoserverv1-657b966cb5-7grqs
Hostname: echoserverv1-657b966cb5-7grqs
Hostname: echoserverv1-657b966cb5-7grqs
Hostname: echoserverv1-657b966cb5-7grqs
复制代码

创建v2版本的服务

我们开启canary功能，将v2版本的权重设置为50%,这个百分比并不能精确的将请求平均分配到两个版本的服务，而是在50%上下浮动

apiVersion: extensions/v1beta1
kind: Ingress
metadata:
  annotations:
    kubernetes.io/ingress.class: nginx
    nginx.ingress.kubernetes.io/canary: "true"
    nginx.ingress.kubernetes.io/canary-weight: "50"
  labels:
    app: echoserverv2
  name: echoserverv2
  namespace: echoserver
spec:
  rules:
  - host: echo.chulinx.com
    http:
      paths:
      - backend:
          serviceName: echoserverv2
          servicePort: 8080
        path: /
---
kind: Service
apiVersion: v1
metadata:
  name:  echoserverv2
  namespace: echoserver
spec:
  selector:
    name:  echoserverv2
  type:  ClusterIP
  ports:
  - name:  echoserverv2
    port:  8080
    targetPort:  8080
---
apiVersion: extensions/v1beta1
kind: Deployment
metadata:
  name:  echoserverv2
  namespace: echoserver
  labels:
    name:  echoserverv2
spec:
  template:
    metadata:
      labels:
        name:  echoserverv2
    spec:
      containers:
      - image:  mirrorgooglecontainers/echoserver:1.10
        name:  echoserverv2 
        ports:
        - containerPort:  8080
          name:  echoserverv2
复制代码

再次查看创建的资源

$ [K8sSj] kubectl get pod,service,ingress -n echoserver
NAME                                READY   STATUS    RESTARTS   AGE
pod/echoserverv1-657b966cb5-7grqs   1/1     Running   0          24h
pod/echoserverv2-856bb5758-f9tqn    1/1     Running   0          4s

NAME                   TYPE        CLUSTER-IP       EXTERNAL-IP   PORT(S)    AGE
service/echoserverv1   ClusterIP   10.99.68.72      <none>        8080/TCP   24h
service/echoserverv2   ClusterIP   10.111.103.170   <none>        8080/TCP   4s

NAME                              HOSTS              ADDRESS   PORTS   AGE
ingress.extensions/echoserverv1   echo.chulinx.com             80      24h
ingress.extensions/echoserverv2   echo.chulinx.com             80      4s
复制代码

访问测试

可以看到请求有4个落到v2版本，6个落到v1版本，理论上来说，请求说越多，落到v2版本的请求数越接近设置的权重50%

$ [K8sSj] for i in `seq 10`;do curl -s echo.chulinx.com|grep Hostname;done
Hostname: echoserverv1-657b966cb5-7grqs
Hostname: echoserverv2-856bb5758-f9tqn
Hostname: echoserverv2-856bb5758-f9tqn
Hostname: echoserverv2-856bb5758-f9tqn
Hostname: echoserverv2-856bb5758-f9tqn
Hostname: echoserverv1-657b966cb5-7grqs
Hostname: echoserverv2-856bb5758-f9tqn
Hostname: echoserverv1-657b966cb5-7grqs
Hostname: echoserverv1-657b966cb5-7grqs
Hostname: echoserverv1-657b966cb5-7grqs
复制代码

2.基于header的A/B测试

更改v2版本的编排文件

增加headernginx.ingress.kubernetes.io/canary-by-header: "v2"

apiVersion: extensions/v1beta1
kind: Ingress
metadata:
  annotations:
    kubernetes.io/ingress.class: nginx
    nginx.ingress.kubernetes.io/canary: "true"
    nginx.ingress.kubernetes.io/canary-weight: "50"
    nginx.ingress.kubernetes.io/canary-by-header: "v2"
  labels:
    app: echoserverv2
  name: echoserverv2
  namespace: echoserver
spec:
  rules:
  - host: echo.chulinx.com
    http:
      paths:
      - backend:
          serviceName: echoserverv2
          servicePort: 8080
        path: /
---
kind: Service
apiVersion: v1
metadata:
  name:  echoserverv2
  namespace: echoserver
spec:
  selector:
    name:  echoserverv2
  type:  ClusterIP
  ports:
  - name:  echoserverv2
    port:  8080
    targetPort:  8080
---
apiVersion: extensions/v1beta1
kind: Deployment
metadata:
  name:  echoserverv2
  namespace: echoserver
  labels:
    name:  echoserverv2
spec:
  template:
    metadata:
      labels:
        name:  echoserverv2
    spec:
      containers:
      - image:  mirrorgooglecontainers/echoserver:1.10
        name:  echoserverv2 
        ports:
        - containerPort:  8080
          name:  echoserverv2
复制代码

更新访问测试

测试了header 为v2:always v2:never v2:true这三个hearder值，可以看到当hearder为v2:always时，流量会全部流入v2，当v2:never时，流量会全部流入v1，当v2:true时，也就是非always/never,流量会按照配置的权重流入对应版本的服务

$ [K8sSj] kubectl apply -f appv2.yml
ingress.extensions/echoserverv2 configured
service/echoserverv2 unchanged
deployment.extensions/echoserverv2 unchanged

$ [K8sSj] for i in `seq 10`;do curl -s -H "v2:always" echo.chulinx.com|grep Hostname;done
Hostname: echoserverv2-856bb5758-f9tqn
Hostname: echoserverv2-856bb5758-f9tqn
Hostname: echoserverv2-856bb5758-f9tqn
Hostname: echoserverv2-856bb5758-f9tqn
Hostname: echoserverv2-856bb5758-f9tqn
Hostname: echoserverv2-856bb5758-f9tqn
Hostname: echoserverv2-856bb5758-f9tqn
Hostname: echoserverv2-856bb5758-f9tqn
Hostname: echoserverv2-856bb5758-f9tqn
Hostname: echoserverv2-856bb5758-f9tqn

$ [K8sSj] for i in `seq 10`;do curl -s -H "v2:never" echo.chulinx.com|grep Hostname;done
Hostname: echoserverv1-657b966cb5-7grqs
Hostname: echoserverv1-657b966cb5-7grqs
Hostname: echoserverv1-657b966cb5-7grqs
Hostname: echoserverv1-657b966cb5-7grqs
Hostname: echoserverv1-657b966cb5-7grqs
Hostname: echoserverv1-657b966cb5-7grqs
Hostname: echoserverv1-657b966cb5-7grqs
Hostname: echoserverv1-657b966cb5-7grqs
Hostname: echoserverv1-657b966cb5-7grqs
Hostname: echoserverv1-657b966cb5-7grqs

$ [K8sSj] for i in `seq 10`;do curl -s -H "v2:true" echo.chulinx.com|grep Hostname;done
Hostname: echoserverv1-657b966cb5-7grqs
Hostname: echoserverv2-856bb5758-f9tqn
Hostname: echoserverv2-856bb5758-f9tqn
Hostname: echoserverv1-657b966cb5-7grqs
Hostname: echoserverv1-657b966cb5-7grqs
Hostname: echoserverv1-657b966cb5-7grqs
Hostname: echoserverv2-856bb5758-f9tqn
Hostname: echoserverv2-856bb5758-f9tqn
Hostname: echoserverv1-657b966cb5-7grqs
Hostname: echoserverv2-856bb5758-f9tqn
复制代码

自定义header-value

apiVersion: extensions/v1beta1
kind: Ingress
metadata:
  annotations:
    kubernetes.io/ingress.class: nginx
    nginx.ingress.kubernetes.io/canary: "true"
    nginx.ingress.kubernetes.io/canary-weight: "50"
    nginx.ingress.kubernetes.io/canary-by-header: "v2"
    nginx.ingress.kubernetes.io/canary-by-header-value: "true"
  labels:
    app: echoserverv2
  name: echoserverv2
  namespace: echoserver
spec:
  rules:
  - host: echo.chulinx.com
    http:
      paths:
      - backend:
          serviceName: echoserverv2
          servicePort: 8080
        path: /
---
kind: Service
apiVersion: v1
metadata:
  name:  echoserverv2
  namespace: echoserver
spec:
  selector:
    name:  echoserverv2
  type:  ClusterIP
  ports:
  - name:  echoserverv2
    port:  8080
    targetPort:  8080
---
apiVersion: extensions/v1beta1
kind: Deployment
metadata:
  name:  echoserverv2
  namespace: echoserver
  labels:
    name:  echoserverv2
spec:
  template:
    metadata:
      labels:
        name:  echoserverv2
    spec:
      containers:
      - image:  mirrorgooglecontainers/echoserver:1.10
        name:  echoserverv2 
        ports:
        - containerPort:  8080
          name:  echoserverv2
复制代码

更新测试

可以看到只有header为v2:never时，请求流量才会流入v2版本，其他值流量都会按照权重设置流入不通版本的服务

$ [K8sSj] kubectl apply -f appv2.yml
ingress.extensions/echoserverv2 configured
service/echoserverv2 unchanged
deployment.extensions/echoserverv2 unchanged

$ [K8sSj] for i in `seq 10`;do curl -s -H "v2:true" echo.chulinx.com|grep Hostname;done
Hostname: echoserverv2-856bb5758-f9tqn
Hostname: echoserverv2-856bb5758-f9tqn
Hostname: echoserverv2-856bb5758-f9tqn
Hostname: echoserverv2-856bb5758-f9tqn
Hostname: echoserverv2-856bb5758-f9tqn
Hostname: echoserverv2-856bb5758-f9tqn
Hostname: echoserverv2-856bb5758-f9tqn
Hostname: echoserverv2-856bb5758-f9tqn
Hostname: echoserverv2-856bb5758-f9tqn
Hostname: echoserverv2-856bb5758-f9tqn

$ [K8sSj] for i in `seq 10`;do curl -s -H "v2:always" echo.chulinx.com|grep Hostname;done
Hostname: echoserverv2-856bb5758-f9tqn
Hostname: echoserverv2-856bb5758-f9tqn
Hostname: echoserverv2-856bb5758-f9tqn
Hostname: echoserverv2-856bb5758-f9tqn
Hostname: echoserverv1-657b966cb5-7grqs
Hostname: echoserverv1-657b966cb5-7grqs
Hostname: echoserverv2-856bb5758-f9tqn
Hostname: echoserverv1-657b966cb5-7grqs
Hostname: echoserverv2-856bb5758-f9tqn
Hostname: echoserverv2-856bb5758-f9tqn

$ [K8sSj] for i in `seq 10`;do curl -s -H "v2:never" echo.chulinx.com|grep Hostname;done
Hostname: echoserverv2-856bb5758-f9tqn
Hostname: echoserverv1-657b966cb5-7grqs
Hostname: echoserverv1-657b966cb5-7grqs
Hostname: echoserverv2-856bb5758-f9tqn
Hostname: echoserverv1-657b966cb5-7grqs
Hostname: echoserverv2-856bb5758-f9tqn
Hostname: echoserverv2-856bb5758-f9tqn
Hostname: echoserverv1-657b966cb5-7grqs
Hostname: echoserverv2-856bb5758-f9tqn
Hostname: echoserverv1-657b966cb5-7grqs
复制代码

3.基于cookie的流控

cookie其实和header原理大致相同，也是ingress自动cookie值，客户访问如果cookie匹配，流量就会流入与之匹配的后端服务

更新v2版本的编排文件

apiVersion: extensions/v1beta1
kind: Ingress
metadata:
  annotations:
    kubernetes.io/ingress.class: nginx
    nginx.ingress.kubernetes.io/canary: "true"
    nginx.ingress.kubernetes.io/canary-weight: "50"
    nginx.ingress.kubernetes.io/canary-by-header: "v2"
    nginx.ingress.kubernetes.io/canary-by-header-value: "true"
    nginx.ingress.kubernetes.io/canary-by-cookie: "user_from_shanghai"
  labels:
    app: echoserverv2
  name: echoserverv2
  namespace: echoserver
spec:
  rules:
  - host: echo.chulinx.com
    http:
      paths:
      - backend:
          serviceName: echoserverv2
          servicePort: 8080
        path: /
---
kind: Service
apiVersion: v1
metadata:
  name:  echoserverv2
  namespace: echoserver
spec:
  selector:
    name:  echoserverv2
  type:  ClusterIP
  ports:
  - name:  echoserverv2
    port:  8080
    targetPort:  8080
---
apiVersion: extensions/v1beta1
kind: Deployment
metadata:
  name:  echoserverv2
  namespace: echoserver
  labels:
    name:  echoserverv2
spec:
  template:
    metadata:
      labels:
        name:  echoserverv2
    spec:
      containers:
      - image:  mirrorgooglecontainers/echoserver:1.10
        name:  echoserverv2 
        ports:
        - containerPort:  8080
          name:  echoserverv2
复制代码

访问测试

可以看和header的访问效果是一样的，只不过cookie不能自定义value

$ [K8sSj] kubectl apply -f appv2.yml
ingress.extensions/echoserverv2 configured
service/echoserverv2 unchanged
deployment.extensions/echoserverv2 unchanged

$ [K8sSj] for i in `seq 10`;do curl -s --cookie "user_from_shanghai" echo.chulinx.com|grep Hostname;done
Hostname: echoserverv1-657b966cb5-7grqs
Hostname: echoserverv1-657b966cb5-7grqs
Hostname: echoserverv2-856bb5758-f9tqn
Hostname: echoserverv1-657b966cb5-7grqs
Hostname: echoserverv2-856bb5758-f9tqn
Hostname: echoserverv2-856bb5758-f9tqn
Hostname: echoserverv1-657b966cb5-7grqs
Hostname: echoserverv2-856bb5758-f9tqn
Hostname: echoserverv2-856bb5758-f9tqn
Hostname: echoserverv2-856bb5758-f9tqn

# zlx @ zlxdeMacBook-Pro in ~/Desktop/unicom/k8syml/nginx-ingress-canary-deployment [16:01:52]
$ [K8sSj] for i in `seq 10`;do curl -s --cookie "user_from_shanghai:always" echo.chulinx.com|grep Hostname;done
Hostname: echoserverv2-856bb5758-f9tqn
Hostname: echoserverv1-657b966cb5-7grqs
Hostname: echoserverv1-657b966cb5-7grqs
Hostname: echoserverv1-657b966cb5-7grqs
Hostname: echoserverv2-856bb5758-f9tqn
Hostname: echoserverv1-657b966cb5-7grqs
Hostname: echoserverv1-657b966cb5-7grqs
Hostname: echoserverv1-657b966cb5-7grqs
Hostname: echoserverv2-856bb5758-f9tqn
Hostname: echoserverv2-856bb5758-f9tqn

# zlx @ zlxdeMacBook-Pro in ~/Desktop/unicom/k8syml/nginx-ingress-canary-deployment [16:02:25]
$ [K8sSj] for i in `seq 10`;do curl -s --cookie "user_from_shanghai=always" echo.chulinx.com|grep Hostname;done
Hostname: echoserverv2-856bb5758-f9tqn
Hostname: echoserverv2-856bb5758-f9tqn
Hostname: echoserverv2-856bb5758-f9tqn
Hostname: echoserverv2-856bb5758-f9tqn
Hostname: echoserverv2-856bb5758-f9tqn
Hostname: echoserverv2-856bb5758-f9tqn
Hostname: echoserverv2-856bb5758-f9tqn
Hostname: echoserverv2-856bb5758-f9tqn
Hostname: echoserverv2-856bb5758-f9tqn
Hostname: echoserverv2-856bb5758-f9tqn