Kubernetes-Statefullset

Statefullset

• 特点

1. 用于部署有状态应用，如mysql
2. pod重启后pod名，挂载的卷不变，ip会变，可以通过
3. statefullset不能关联常规的svc，不具有负载均衡的能力，但可以关联无头svc
4. 无头svc通过，pod名.svc名访问

• statefullset

trnuser@k8s:~/pod/sts$ cat sts.yaml 
apiVersion: apps/v1
kind: StatefulSet
metadata:
  name: web
spec:
  selector:
    matchLabels:
      app: nginx 
  serviceName: "nginx"
  replicas: 2
  template:
    metadata:
      labels:
        app: nginx 
    spec:
      containers:
      - name: nginx
        image: nginx
        volumeMounts:
        - name: www
          mountPath: /usr/share/nginx/html
  volumeClaimTemplates: 
  - metadata:
      name: www
    spec:
      accessModes: [ "ReadWriteOnce" ]
      storageClassName: "xx" 
      resources:
        requests:
          storage: 1Gi

• svc

trnuser@k8s:~/pod/sts$ cat svc.yaml 
apiVersion: v1
kind: Service
metadata:
  name: nginx
  labels:
    app: nginx
spec:
  ports:
  - port: 80
    name: web
  clusterIP: None
  selector:
    app: nginx