环境
kubernetes v1.15
nginx-ingress-controller v0.32.0
介绍
金丝雀发布：又叫灰度发布，控制产品从A版本平滑的过度到B版本
ingress-nginx：k8s ingress工具，支持金丝雀发布，可以实现基于权重、请求头、请求头的值、cookie转发流量。
rancher：k8s集群管理工具，使用UI简化k8s相关操作
ingress-nginx canary官方说明：//github.com/kubernetes/ingress-nginx/blob/master/docs/user-guide/nginx-configuration/annotations.md#canary
首先创建两个nginx应用
#deployment.yaml
apiVersion: apps/v1
kind: Deployment
metadata:
name: appv1
labels:
app: v1
spec:
replicas: 1
selector:
matchLabels:
app: v1
template:
metadata:
labels:
app: v1
spec:
containers:
- name: nginx
image: zerchin/canary:v1
ports:
- containerPort: 80
---
apiVersion: apps/v1
kind: Deployment
metadata:
name: appv2
labels:
app: v2
spec:
replicas: 1
selector:
matchLabels:
app: v2
template:
metadata:
labels:
app: v2
spec:
containers:
- name: nginx
image: zerchin/canary:v2
ports:
- containerPort: 80
kubectl查看pod
kubectl get pod -o wide |grep app
appv1-69bf545f96-lkqfm 1/1 Running 0 89m 172.17.0.12 minikube <none> <none>
appv2-787866684-b9hhh 1/1 Running 0 89m 172.17.0.11 minikube <none> <none>
这两个应用输出以下内容
$ curl 172.17.0.12
v1
$
$ curl 172.17.0.11
canary-v2
分别为应用创建对应的service
假设你已经了解了svc 和deployment概念，这步操作你应该了解。
#service.yaml
apiVersion: v1
kind: Service
metadata:
name: appv1
spec:
selector:
app: v1
ports:
- protocol: TCP
port: 80
targetPort: 80
---
apiVersion: v1
kind: Service
metadata:
name: appv2
spec:
selector:
app: v2
ports:
- protocol: TCP
port: 80
targetPort: 80
验证svc是否成功运行了
kubectl get svc |grep app
appv1 ClusterIP 10.109.87.198 <none> 80/TCP 7m
appv2 ClusterIP 10.106.40.192 <none> 80/TCP 7m
部署一个正常的ingress
路由到appv1上
#ingress.yaml
apiVersion: extensions/v1beta1
kind: Ingress
metadata:
name: app
namespace: default
spec:
rules:
- host: nginx2.192.168.99.101.xip.io
http:
paths:
- backend:
serviceName: appv1
servicePort: 80
path: /
kubectl查看ingress
kubectl get ingress
NAME HOSTS ADDRESS PORTS AGE
app nginx2.192.168.99.101.xip.io 192.168.99.101 80 9m43s
访问nginx2.192.168.99.101.xip.io
curl nginx2.192.168.99.101.xip.io
###v1
金丝雀发布
有三种方法
金丝雀发布规则优先级：canary-by-header -> canary-by-cookie -> canary-weight
目前，每个ingress规则最多可以应用一个canary ingress
我把yaml文件贴出来，注释掉分别就可以用了。
#canary.yaml
apiVersion: extensions/v1beta1
kind: Ingress
metadata:
annotations:
kubernetes.io/ingress.class: nginx
nginx.ingress.kubernetes.io/canary: "true"
# 基于cookie转发流量 nginx.ingress.kubernetes.io/canary-by-cookie: "test"
# 基于请求头转发流量 nginx.ingress.kubernetes.io/canary-by-header: "canary"
# 基于请求头和请求头的值转发流量 nginx.ingress.kubernetes.io/canary-by-header-value: "haha"
基于权重转发流量 nginx.ingress.kubernetes.io/canary-weight: "30"
name: app-canary
namespace: default
spec:
rules:
- host: nginx2.192.168.99.101.xip.io
http:
paths:
- backend:
serviceName: appv2
servicePort: 80
path: /
1.基于权重转发流量
nginx.ingress.kubernetes.io/canary-by-header：用于通知Ingress将请求路由到Canary Ingress中指定的服务的标头。当请求标头设置always为时，它将被路由到Canary。当标头设置never为时，它将永远不会路由到金丝雀。对于任何其他值，标头将被忽略，并且按优先级将请求与其他金丝雀规则进行比较。
修改app-canary的ingress配置，修改annotation，如下：
annotations:
kubernetes.io/ingress.class: nginx
nginx.ingress.kubernetes.io/canary: "true"
nginx.ingress.kubernetes.io/canary-by-header: "canary"
结果
for i in `seq 1 10`;do curl http://nginx2.192.168.99.101.xip.io/;done
canary-v2
canary-v2
canary-v2
v1
v1
v1
v1
v1
v1
v1
2.基于请求头转发流量
nginx.ingress.kubernetes.io/canary-by-header：用于通知Ingress将请求路由到Canary Ingress中指定的服务的标头。当请求标头设置always为时，它将被路由到Canary。当标头设置never为时，它将永远不会路由到金丝雀。对于任何其他值，标头将被忽略，并且按优先级将请求与其他金丝雀规则进行比较。
修改app-canary的ingress配置，修改annotation，如下：
annotations:
kubernetes.io/ingress.class: nginx
nginx.ingress.kubernetes.io/canary: "true"
nginx.ingress.kubernetes.io/canary-by-header: "canary"
测试结果
# curl http://nginx2.192.168.99.101.xip.io/
v1
# curl -H "canary:always" http://nginx2.192.168.99.101.xip.io/
canary-v2
3.基于请求头和请求头的值转发流量
nginx.ingress.kubernetes.io/canary-by-header-value：匹配的报头值，用于通知Ingress将请求路由到Canary Ingress中指定的服务。当请求标头设置为此值时，它将被路由到Canary。对于任何其他标头值，标头将被忽略，并按优先级将请求与其他金丝雀规则进行比较。此注释必须与nginx.ingress.kubernetes.io/canary-by-header一起使用。
修改app-canary的ingress配置，修改annotation，如下：
annotations:
kubernetes.io/ingress.class: nginx
nginx.ingress.kubernetes.io/canary: "true"
nginx.ingress.kubernetes.io/canary-by-header: "canary"
nginx.ingress.kubernetes.io/canary-by-header-value: "haha"
测试
# curl http://nginx2.192.168.99.101.xip.io/
v1
# curl -H "canary:haha" http://nginx2.192.168.99.101.xip.io/
canary-v2
# curl -H "canary:always" http://nginx2.192.168.99.101.xip.io/
v1
4.基于cookie转发流量
nginx.ingress.kubernetes.io/canary-by-cookie：用于通知Ingress将请求路由到Canary Ingress中指定的服务的cookie。当cookie值设置always为时，它将被路由到canary。当cookie设置never为时，它将永远不会路由到Canary。对于任何其他值，将忽略cookie，并按优先级将请求与其他canary规则进行比较。
修改app-canary的ingress配置，修改annotation，如下：
annotations:
kubernetes.io/ingress.class: nginx
nginx.ingress.kubernetes.io/canary: "true"
nginx.ingress.kubernetes.io/canary-by-cookie: "test"
测试结果
# curl http://nginx2.192.168.99.101.xip.io/
v1
# curl -b "test=never" http://nginx2.192.168.99.101.xip.io/
v1
# curl -b "test=always" http://nginx2.192.168.99.101.xip.io/
canary-v2
# curl -b "test=1" http://nginx2.192.168.99.101.xip.io/
v1
高级的可以参考：
Kubernetes Ingress-nginx使用
