k8s中基于 nginx-ingress 的灰度发布是什么

k8s中基于 nginx-ingress 的灰度发布是什么，相信很多没有经验的人对此束手无策，为此本文总结了问题出现的原因和解决方法，通过这篇文章希望你能解决这个问题。

假设当前线上环境我们已经有一套服务 app-old 对外提供 7 层服务，此时我们修复了一些问题，需要灰度发布上线一个新的版本 app-new，但是我们又不希望简单直接地将所有客户端流量切换到新版本 app-new 中，而是希望仅仅切换 20% 的流量到新版本 app-new 中，待运行一段时间稳定，将所有的流量切换到 app-new 服务中后，再平滑地下线掉 app-old 服务。

针对以上多种不同的应用发布需求，K8S Ingress Controller 支持了多种流量切分方式：

1. 基于 Request Header 的流量切分，适用于灰度发布以及 AB 测试场景

2. 基于 Cookie 的流量切分，适用于灰度发布以及 AB 测试场景

3. 基于 Query Param 的流量切分，适用于灰度发布以及 AB 测试场景

4. 基于服务权重的流量切分，适用于蓝绿发布场景

以下测试基于服务权重的流量切分，也可以将nginx.ingress.kubernetes.io/canary-weight: "30"改为基于 header 的流量切分。

准备老版本程序

老版本程序 app-old

app-old.yaml

apiVersion: extensions/v1beta1kind: Deploymentmetadata:  name: app-oldspec:  replicas: 2  selector:    matchLabels:      run: app-old  template:    metadata:      labels:        run: app-old    spec:      containers:      - image: zouhl/app:v2.1        imagePullPolicy: Always        name: app-old        ports:        - containerPort: 80          protocol: TCP      restartPolicy: Always---apiVersion: v1kind: Servicemetadata:  name: app-oldspec:  ports:  - port: 80    protocol: TCP    targetPort: 80  selector:    run: app-old  sessionAffinity: None  type: NodePor

apiVersion: extensions/v1beta1 kind: Deployment metadata: name: app-old spec: replicas: 2 selector: matchLabels: run: app-old template: metadata: labels: run: app-old spec: containers: - image: zouhl/app:v2.1 imagePullPolicy: Always name: app-old ports: - containerPort: 80 protocol: TCP restartPolicy: Always --- apiVersion: v1 kind: Service metadata: name: app-old spec: ports: - port: 80 protocol: TCP targetPort: 80 selector: run: app-old sessionAffinity: None type: NodePor

老版本的 ingress

app-v1.yaml

apiVersion: extensions/v1beta1kind: Ingressmetadata:  name: my-app  labels:    app: my-app  annotations:    kubernetes.io/ingress.class: nginx  namespace: defaultspec:  rules:    - host: test.192.168.2.20.xip.io      http:        paths:          - backend:              serviceName: app-old              servicePort: 80            path: /

apiVersion: extensions/v1beta1 kind: Ingress metadata: name: my-app labels: app: my-app annotations: kubernetes.io/ingress.class: nginx namespace: default spec: rules: - host: test.192.168.2.20.xip.io http: paths: - backend: serviceName: app-old servicePort: 80 path: /

在 k8s 中创建

kubectl create -f app-old.yamlkubectl create -f app-v1.yaml

kubectl create -f app-old.yaml kubectl create -f app-v1.yaml

装备新版本程序

新版本app-new.yaml

apiVersion: extensions/v1beta1kind: Deploymentmetadata:  name: app-newspec:  replicas: 2  selector:    matchLabels:      run: app-new  template:    metadata:      labels:        run: app-new    spec:      containers:      - image: zouhl/app:v2.2        imagePullPolicy: Always        name: app-new        ports:        - containerPort: 80          protocol: TCP      restartPolicy: Always---apiVersion: v1kind: Servicemetadata:  name: app-newspec:  ports:  - port: 80    protocol: TCP    targetPort: 80  selector:    run: app-new  sessionAffinity: None  type: NodePort

apiVersion: extensions/v1beta1 kind: Deployment metadata: name: app-new spec: replicas: 2 selector: matchLabels: run: app-new template: metadata: labels: run: app-new spec: containers: - image: zouhl/app:v2.2 imagePullPolicy: Always name: app-new ports: - containerPort: 80 protocol: TCP restartPolicy: Always --- apiVersion: v1 kind: Service metadata: name: app-new spec: ports: - port: 80 protocol: TCP targetPort: 80 selector: run: app-new sessionAffinity: None type: NodePort

新版本 canary-ingress

app-v2-canary.yaml

apiVersion: extensions/v1beta1kind: Ingressmetadata:  name: my-app-canary  labels:    app: my-app  annotations:    kubernetes.io/ingress.class: nginx    nginx.ingress.kubernetes.io/canary: "true"    nginx.ingress.kubernetes.io/canary-weight: "30"  namespace: defaultspec:  rules:    - host: test.192.168.2.20.xip.io      http:        paths:          - backend:              serviceName: app-new              servicePort: 80            path: /

apiVersion: extensions/v1beta1 kind: Ingress metadata: name: my-app-canary labels: app: my-app annotations: kubernetes.io/ingress.class: nginx nginx.ingress.kubernetes.io/canary: "true" nginx.ingress.kubernetes.io/canary-weight: "30" namespace: default spec: rules: - host: test.192.168.2.20.xip.io http: paths: - backend: serviceName: app-new servicePort: 80 path: /

新版本 ingress yaml

app-v2.yaml

apiVersion: extensions/v1beta1kind: Ingressmetadata:  name: my-app  labels:    app: my-app  annotations:    kubernetes.io/ingress.class: nginx  namespace: defaultspec:  rules:    - host: test.192.168.2.20.xip.io      http:        paths:          - backend:              serviceName: app-new              servicePort: 80            path: /

apiVersion: extensions/v1beta1 kind: Ingress metadata: name: my-app labels: app: my-app annotations: kubernetes.io/ingress.class: nginx namespace: default spec: rules: - host: test.192.168.2.20.xip.io http: paths: - backend: serviceName: app-new servicePort: 80 path: /

发布流程

$ tree                                              .├── app-new.yaml├── app-old.yaml├── app-v1.yaml├── app-v2-canary.yaml└── app-v2.yaml

$ tree . ├── app-new.yaml ├── app-old.yaml ├── app-v1.yaml ├── app-v2-canary.yaml └── app-v2.yaml

app-v1 已经发布了，现在灰度发布第二版，权重为 30%，nginx.ingress.kubernetes.io/canary-weight: "30"，更多参数参考github

kubectl create -f app-new.yamlkubectl create -f app-v2-canary.yaml

kubectl create -f app-new.yaml kubectl create -f app-v2-canary.yaml

检查

$ kubectl get ingresses.extensions   NAME            HOSTS                       ADDRESS   PORTS   AGEapp-ingress     www.example.com                       80      109mmy-app          test.192.168.2.20.xip.io              80      25mmy-app-canary   test.192.168.2.20.xip.io              80      1snginx-test      nginx.192.168.2.20.xip.io             80      3h22m

$ kubectl get ingresses.extensions NAME HOSTS ADDRESS PORTS AGE app-ingress www.example.com 80 109m my-app test.192.168.2.20.xip.io 80 25m my-app-canary test.192.168.2.20.xip.io 80 1s nginx-test nginx.192.168.2.20.xip.io 80 3h22m

在后台观察，70% to v1，30% to v2

$ while sleep 0.5; do curl "test.192.168.2.20.xip.io";echo; done{"v2.2 hostname":"app-new-658dfc9c6b-lbmvr"}{"v2.2 hostname":"app-new-658dfc9c6b-qhwtg"}{"v1 hostname":"app-old-64fd44b699-4hvlb"}{"v1 hostname":"app-old-64fd44b699-zb58f"}

$ while sleep 0.5; do curl "test.192.168.2.20.xip.io";echo; done {"v2.2 hostname":"app-new-658dfc9c6b-lbmvr"} {"v2.2 hostname":"app-new-658dfc9c6b-qhwtg"} {"v1 hostname":"app-old-64fd44b699-4hvlb"} {"v1 hostname":"app-old-64fd44b699-zb58f"}

如果一切正常则可以正式发布

# delete the canary ingresskubectl delete -f app-v2-canary.yaml# set 100% traffic to v2kubectl apply -f app-v2.yaml

# delete the canary ingress kubectl delete -f app-v2-canary.yaml # set 100% traffic to v2 kubectl apply -f app-v2.yaml

检查 ingress

$ kubectl get ingresses.extensions    NAME          HOSTS                       ADDRESS   PORTS   AGEapp-ingress   www.example.com                       80      109mmy-app        test.192.168.2.20.xip.io              80      25mnginx-test    nginx.192.168.2.20.xip.io             80      3h23m$ while sleep 0.5; do curl "test.192.168.2.20.xip.io";echo; done{"v2.2 hostname":"app-new-658dfc9c6b-lbmvr"}{"v2.2 hostname":"app-new-658dfc9c6b-qhwtg"}

$ kubectl get ingresses.extensions NAME HOSTS ADDRESS PORTS AGE app-ingress www.example.com 80 109m my-app test.192.168.2.20.xip.io 80 25m nginx-test nginx.192.168.2.20.xip.io 80 3h23m $ while sleep 0.5; do curl "test.192.168.2.20.xip.io";echo; done {"v2.2 hostname":"app-new-658dfc9c6b-lbmvr"} {"v2.2 hostname":"app-new-658dfc9c6b-qhwtg"}

看完上述内容，你们掌握k8s中基于 nginx-ingress 的灰度发布是什么的方法了吗？如果还想学到更多技能或想了解更多相关内容，欢迎关注行业资讯频道，感谢各位的阅读！