实验的环境：
1、已经搭建好k8s环境的3台 centos 7.9机器。1个master,2个worker节点。 k8s版本为1.20.4
2、在k8s里安装好 ingress nginx,安装教程请看
实战
一、创建一个常规的应用
1、将镜像文件 openresty.tar.gz传入 2个workder节点，docker load 安装镜像；这个镜像相当于nginx的一个高级版本。
2、创建1个常规的应用，包括 Deployment,Service,Ingress资源。
v1.yaml
apiVersion: apps/v1 kind: Deployment metadata: name: nginx-v1 spec: replicas: 1 selector: matchLabels: app: nginx version: v1 template: metadata: labels: app: nginx version: v1 spec: containers: - name: nginx image: "openresty/openresty:centos" imagePullPolicy: IfNotPresent ports: - name: http protocol: TCP containerPort: 80 volumeMounts: - mountPath: /usr/local/openresty/nginx/conf/nginx.conf name: config subPath: nginx.conf volumes: - name: config configMap: name: nginx-v1 --- apiVersion: v1 kind: ConfigMap metadata: labels: app: nginx version: v1 name: nginx-v1 data: nginx.conf: |- worker_processes 1; events { accept_mutex on; multi_accept on; use epoll; worker_connections 1024; } http { ignore_invalid_headers off; server { listen 80; location / { access_by_lua ' local header_str = ngx.say("nginx-v1") '; } } } --- apiVersion: v1 kind: Service metadata: name: nginx-v1 spec: type: ClusterIP ports: - port: 80 protocol: TCP name: http selector: app: nginx version: v1
v1-ingress.yaml
apiVersion: extensions/v1beta1 kind: Ingress metadata: name: nginx annotations: kubernetes.io/ingress.class: nginx spec: rules: - host: canary.example.com http: paths: - backend: serviceName: nginx-v1 servicePort: 80 path: /
从yaml文件中，我们可以看到，创建了一个应用,标签 app为nginx,version为v1 .
只返回一句话 "nginx-v1" 。访问的域名为 ：canary.example.com
kubectl apply -f 执行这2个yaml文件，等待1分钟左右。
3、访问验证一下:
$ curl -H "Host: canary.example.com" http://EXTERNAL-IP # EXTERNAL-IP 替换为Nginx Ingress 自身对外暴露的 IP
我的实验环境为：
curl -H "Host: canary.example.com" http://192.168.24.21
返回 nginx-v1
4、创建一个灰度版本（金丝雀版本）的资源 ，包 Deploy,Service
v2.yaml
apiVersion: apps/v1 kind: Deployment metadata: name: nginx-v2 spec: replicas: 1 selector: matchLabels: app: nginx version: v2 template: metadata: labels: app: nginx version: v2 spec: containers: - name: nginx image: "openresty/openresty:centos" imagePullPolicy: IfNotPresent ports: - name: http protocol: TCP containerPort: 80 volumeMounts: - mountPath: /usr/local/openresty/nginx/conf/nginx.conf name: config subPath: nginx.conf volumes: - name: config configMap: name: nginx-v2 --- apiVersion: v1 kind: ConfigMap metadata: labels: app: nginx version: v2 name: nginx-v2 data: nginx.conf: |- worker_processes 1; events { accept_mutex on; multi_accept on; use epoll; worker_connections 1024; } http { ignore_invalid_headers off; server { listen 80; location / { access_by_lua ' local header_str = ngx.say("nginx-v2") '; } } } --- apiVersion: v1 kind: Service metadata: name: nginx-v2 spec: type: ClusterIP ports: - port: 80 protocol: TCP name: http selector: app: nginx version: v2
从yaml文件中，我们可以看到，创建了一个应用,标签 app为nginx,version为v2.
只返回一句话 "nginx-v2" 。
执行v2.yaml
二、基于 Header 的流量切分
1、创建 Canary Ingress，指定 v2 版本的后端服务，且加上一些 annotation，实现仅将带有名为Region 且值为 cd 或 sz 的请求头的请求转发给当前 Canary Ingress，模拟灰度新版本给成都和深圳地域的用户:
v2-ingress.yaml
apiVersion: extensions/v1beta1 kind: Ingress metadata: annotations: kubernetes.io/ingress.class: nginx nginx.ingress.kubernetes.io/canary: "true" nginx.ingress.kubernetes.io/canary-by-header: "Region" nginx.ingress.kubernetes.io/canary-by-header-pattern: "cd|sz" name: nginx-canary spec: rules: - host: canary.example.com http: paths: - backend: serviceName: nginx-v2 servicePort: 80 path: /
这个与v1.ingress.yaml文件相比，host域名是相同的，serviceName指向 nginx-v2版本。加了一些注解。
执行这个yaml文件。
kubectl apply -f v2-ingress.yaml
2、测试访问:
$ curl -H "Host: canary.example.com" -H "Region: cd" http://EXTERNAL-IP #EXTERNAL-IP 替换为 Nginx Ingress 自身对外暴露的 IP
[root@k8s-master ingress-nginx]# curl -H "Host: canary.example.com" -H "Region: bj" http://192.168.24.21 nginx-v1 [root@k8s-master ingress-nginx]# curl -H "Host: canary.example.com" -H "Region: cd" http://192.168.24.21 nginx-v2
可以看到，只有 header Region 为 cd 或 sz 的请求才由 v2 版本服务响应。
三、基于 Cookie 的流量切分：
1、与前面 Header 类似，不过使用 Cookie 就无法自定义 value 了，这里以模拟灰度成都地域用户为例，仅将带有名为 user_from_cd 的 cookie 的请求转发给当前 Canary Ingress 。先删除前面基于 Header 的流量切分的 Canary Ingress，然后创建下面新的 Canary Ingress:
kubectl delete -f v2-ingress.yaml
2、vim v1-cookie.yaml
apiVersion: extensions/v1beta1 kind: Ingress metadata: annotations: kubernetes.io/ingress.class: nginx nginx.ingress.kubernetes.io/canary: "true" nginx.ingress.kubernetes.io/canary-by-cookie: "user_from_cd" name: nginx-canary spec: rules: - host: canary.example.com http: paths: - backend: serviceName: nginx-v2 servicePort: 80 path: /
kubectl apply -f v1-cookie.yaml
3、验证
[root@k8s-master ingress-nginx]# curl -s -H "Host: canary.example.com" --cookie "user_from_cd=always" http://192.168.24.21 nginx-v2 [root@k8s-master ingress-nginx]# curl -s -H "Host: canary.example.com" --cookie "user_from_cd=111" http://192.168.24.21 nginx-v1
[root@k8s-master ingress-nginx]# curl -s -H "Host: canary.example.com" http://192.168.24.21 nginx-v1
可以看到，只有 cookie user_from_cd 为 always 的请求才由 v2 版本的服务响应。
四、基于服务权重的流量切分
1、基于服务权重的 Canary Ingress 就简单了，直接定义需要导入的流量比例，这里以导入 10% 流量到 v2 版本为例 (如果有，先删除之前的 Canary Ingress):
kubectl delete -f v1-cookie.yaml
2、vim v1-weight.yaml
apiVersion: extensions/v1beta1 kind: Ingress metadata: annotations: kubernetes.io/ingress.class: nginx nginx.ingress.kubernetes.io/canary: "true" nginx.ingress.kubernetes.io/canary-weight: "10" name: nginx-canary spec: rules: - host: canary.example.com http: paths: - backend: serviceName: nginx-v2 servicePort: 80 path: /
kubectl apply -f v1-weight.yaml
3、验证：
for i in {1..10}; do curl -H "Host: canary.example.com" http://192.168.24.21; done;
[root@k8s-master ingress-nginx]# for i in {1..10}; do curl -H "Host: canary.example.com" http://192.168.24.21; done; nginx-v1 nginx-v1 nginx-v1 nginx-v1 nginx-v1 nginx-v1 nginx-v2 nginx-v1 nginx-v1 nginx-v1
可以看到，大概只有十分之一的几率由 v2 版本的服务响应，符合 10% 服务权重的设置。