StatefulSet扩缩容源码分析

k8s v1.15.0

Informer监听

cmd/kube-controller-manager/app/apps.go

作为StatefulSet资源控制器，StatefulSetController通过PodInformer、StatefulSetInformer、PersistentVolumeClaimInformer、ControllerRevisionInformer来监听事件。

StatefulSet Controller通过resync来同步丢失的事件，同步时间是[12h, 24h)随机值，其他controller也是如此。

扩缩容StatefulSet

podManagementPolicy
Parallel
并行创建或者删除Pod

pkg/controller/statefulset/stateful_set_control.go
updateStatefulSet方法
monotonic判断是否为并行管理策略

Parallel场景并行创建Pod

收集需要删除的Pod

Parallel场景并行删除Pod

apiVersion: v1
kind: Service
metadata:
  name: nginx
spec:
  ports:
  - port: 80
  selector:
    app: nginx
---
apiVersion: apps/v1
kind: StatefulSet
metadata:
  name: nginx
spec:
  podManagementPolicy: Parallel
  serviceName: nginx
  replicas: 2
  selector:
    matchLabels:
      app: nginx
  template:
    metadata:
      labels:
        app: nginx
    spec:
      containers:
      - name: nginx
        image: nginx:1.9.1

参考资料

Kubernetes StatefulSet源码分析

statefulset controller 源码分析