K8S statefulset

StatefulSet详解
kubectl explain sts.spec ：主要字段解释
replicas ：副本数
selector：那个pod是由自己管理的
serviceName：必须关联到一个无头服务商
template：定义pod模板（其中定义关联那个存储卷）
volumeClaimTemplates ：生成PVC

cat << EOF > nginx-ss.yaml
apiVersion: apps/v1
kind: StatefulSet
metadata:
  name: web
  namespace: nginx-ss
spec:
  selector:
    matchLabels:
      app: nginx #必须匹配 .spec.template.metadata.labels
  serviceName: "nginx"  #声明它属于哪个Headless Service.
  replicas: 3 #副本数
  template:
    metadata:
      labels:
        app: nginx # 必须配置 .spec.selector.matchLabels
    spec:
      terminationGracePeriodSeconds: 10
      containers:
      - name: nginx
        image: www.my.com/web/nginx:v1
        ports:
        - containerPort: 80
          name: web
        volumeMounts:
        - name: nginx-pvc
          mountPath: /usr/share/nginx/html

  volumeClaimTemplates:   #可看作pvc的模板
  - metadata:
      name: nginx-pvc
    spec:
      accessModes: [ "ReadWriteOnce" ]
      storageClassName: "nginx-nfs-storage"  #存储类名，改为集群中已存在的
      resources:
        requests:
          storage: 1Gi
EOF