ClusterClass总结

参考文档：
https://kubernetes.io/blog/2021/10/08/capi-clusterclass-and-managed-topologies/

一、ClusterClass基本概念

ClusterClass 背后的理念很简单：一次定义集群，多次重复使用，将 Kubernetes 集群的复杂性和内部结构抽象化。

---
apiVersion: cluster.x-k8s.io/v1beta1
kind: ClusterClass
metadata:
  name: my-amazing-cluster-class
spec:
  controlPlane:
    ref:
      apiVersion: controlplane.cluster.x-k8s.io/v1beta1
      kind: KubeadmControlPlaneTemplate
      name: high-availability-control-plane
    machineInfrastructure:
      ref:
        apiVersion: infrastructure.cluster.x-k8s.io/v1beta1
        kind: DockerMachineTemplate
        name: control-plane-machine
  workers:
    machineDeployments:
      - class: type1-workers
        template:
          bootstrap:
            ref:
              apiVersion: bootstrap.cluster.x-k8s.io/v1beta1
              kind: KubeadmConfigTemplate
              name: type1-bootstrap
          infrastructure:
            ref:
              apiVersion: infrastructure.cluster.x-k8s.io/v1beta1
              kind: DockerMachineTemplate
              name: type1-machine
      - class: type2-workers
        template:
          bootstrap:
            ref:
              apiVersion: bootstrap.cluster.x-k8s.io/v1beta1
              kind: KubeadmConfigTemplate
              name: type2-bootstrap
          infrastructure:
            ref:
              kind: DockerMachineTemplate
              apiVersion: infrastructure.cluster.x-k8s.io/v1beta1
              name: type2-machine
  infrastructure:
    ref:
      apiVersion: infrastructure.cluster.x-k8s.io/v1beta1
      kind: DockerClusterTemplate
      name: cluster-infrastructure

---
apiVersion: cluster.x-k8s.io/v1beta1
 kind: Cluster
 metadata:
   name: my-amazing-cluster
   namespace: bar
 spec:
   topology: # define a managed topology
     class: my-amazing-cluster-class # use the ClusterClass mentioned earlier
     version: v1.21.2
     controlPlane:
       replicas: 3
     workers:
       machineDeployments:
       - class: type1-workers
         name: big-pool-of-machines
         replicas: 5
       - class: type2-workers
         name: small-pool-of-machines
         replicas: 1

二、ClusterClass源码分析

三、machineDeployment源码分析

1、machineDeployment其实和deployment源码相似，machineset和machinedeployment分工如下:

• machineset: 负责machine和inframachine的创建，控制其数量为machineset里的副本数
• machinedeploy：负责控制更上层，滚动升级等