蓝绿(blue/green)
:新版本与旧版本一起存在,然后切换流量
- 通过
k8s service label
标签来实现蓝绿发布 - 通过
Ingress 控制器
来实现蓝绿发布 - 通过
Istio
来实现蓝绿发布,或者像Istio类似的服务
这次先讲通过k8s service label
标签来实现蓝绿发布
,Istio
实现蓝绿发布下期再分享。
- service.yaml 文件
apiVersion: v1
kind: Service
metadata:
name: demo
namespace: default
labels:
app: demo
spec:
ports:
- port: 80
targetPort: http
protocol: TCP
name: http
# 注意这里我们匹配 app 和 version 标签,当要切换流量的时候,我们更新 version 标签的值,比如:v2
selector:
app: demo
version: v1
- 蓝 v1-deploy.yaml 文件
apiVersion: apps/v1
kind: Deployment
metadata:
name: demo1-deployment
namespace: default
labels:
app: demo
version: v1
spec:
replicas: 1
revisionHistoryLimit: 3
strategy:
rollingUpdate:
maxSurge: 30%
maxUnavailable: 30%
selector:
matchLabels:
app: demo
version: v1
template:
metadata:
labels:
app: demo
version: v1
spec:
containers:
- name: demo1
image: mritd/demo
livenessProbe:
httpGet:
path: /
port: 80
scheme: HTTP
initialDelaySeconds: 30
timeoutSeconds: 5
periodSeconds: 30
successThreshold: 1
failureThreshold: 5
readinessProbe:
httpGet:
path: /
port: 80
scheme: HTTP
initialDelaySeconds: 30
timeoutSeconds: 5
periodSeconds: 10
successThreshold: 1
failureThreshold: 5
ports:
- name: http
containerPort: 80
protocol: TCP
- 绿 v2-deploy.yaml
apiVersion: apps/v1
kind: Deployment
metadata:
name: demo2-deployment
namespace: default
labels:
app: demo
version: v2
spec:
replicas: 1
revisionHistoryLimit: 3
strategy:
rollingUpdate:
maxSurge: 30%
maxUnavailable: 30%
selector:
matchLabels:
app: demo
version: v2
template:
metadata:
labels:
app: demo
version: v2
spec:
containers:
- name: demo2
image: mritd/demo
livenessProbe:
httpGet:
path: /
port: 80
scheme: HTTP
initialDelaySeconds: 30
timeoutSeconds: 5
periodSeconds: 30
successThreshold: 1
failureThreshold: 5
readinessProbe:
httpGet:
path: /
port: 80
scheme: HTTP
initialDelaySeconds: 30
timeoutSeconds: 5
periodSeconds: 10
successThreshold: 1
failureThreshold: 5
ports:
- name: http
containerPort: 80
protocol: TCP
- 上面定义的资源对象中,最重要的就是
Service 中 label selector
的定义:
selector:
app: demo
version: v1
- 部署v1 v2 deploy服务 和 service服务
$ kubectl apply -f service.yaml -f v1-deploy.yaml -f v2-deploy.yaml
- 测试流量是否到v1版本
# 登陆任意一个pod,向 demo service 发起请求
$ while sleep 0.3; do curl http://demo; done
# 输出日志
Host: demo1-deployment-b5bd596d8-dw27b, Version: v1
Host: demo1-deployment-b5bd596d8-dw27b, Version: v1
- 切换入口流量从v1 到 v2
$ kubectl patch service demo -p '{"spec":{"selector":{"version":"v2"}}}'
- 测试流量是否到v2版本
# 登陆任意一个pod,向 demo service 发起请求
$ while sleep 0.3; do curl http://demo; done
# 输出日志
Host: demo2-deployment-b5bd596d8-dw27b, Version: v2
Host: demo2-deployment-b5bd596d8-dw27b, Version: v2