来自https://www.katacoda.com/openshift/courses/operatorframework/etcd-operator

cat > etcd-operator-crd.yaml<<EOF
# 扩展资源的组
apiVersion: apiextensions.k8s.io/v1
# CRD
kind: CustomResourceDefinition
metadata:
# 这个CRD的名字，好像没啥用
  name: etcdclusters.etcd.database.coreos.com
spec:
# CRD的组
  group: etcd.database.coreos.com
#   
  names:
    kind: EtcdCluster
    listKind: EtcdClusterList
    plural: etcdclusters
    shortNames:
    - etcdclus
    - etcd
    singular: etcdcluster
  scope: Namespaced
# 版本  
  version: v1beta2
  versions:
  - name: v1beta2
    schema:
      openAPIV3Schema:
        type: object
        x-kubernetes-preserve-unknown-fields: true
    served: true
    storage: true
EOF

# etcd operator的账户()
cat > etcd-operator-sa.yaml<<EOF
apiVersion: v1
kind: ServiceAccount
metadata:
  name: etcd-operator-sa
EOF

# 创建一个角色，角色肯定是有权限的
cat > etcd-operator-role.yaml<<EOF
apiVersion: rbac.authorization.k8s.io/v1
kind: Role
metadata:
  name: etcd-operator-role
rules:
- apiGroups:
  - etcd.database.coreos.com
  resources:
  - etcdclusters
  - etcdbackups
  - etcdrestores
  verbs:
  - '*'
- apiGroups:
  - ""
  resources:
  - pods
  - services
  - endpoints
  - persistentvolumeclaims
  - events
  verbs:
  - '*'
- apiGroups:
  - apps
  resources:
  - deployments
  verbs:
  - '*'
- apiGroups:
  - ""
  resources:
  - secrets
  verbs:
  - get
EOF

# 赋予账户角色，也就是权限
cat > etcd-operator-rolebinding.yaml<<EOF
apiVersion: rbac.authorization.k8s.io/v1
kind: RoleBinding
metadata:
  name: etcd-operator-rolebinding
roleRef:
  apiGroup: rbac.authorization.k8s.io
  kind: Role
  name: etcd-operator-role
subjects:
- kind: ServiceAccount
  name: etcd-operator-sa
  namespace: myproject
EOF


# 部署etcd的operator，本质上是一个deploy，但是这个deploy控制着整个etcd cluster
cat > etcd-operator-deployment.yaml<<EOF
apiVersion: apps/v1
kind: Deployment
metadata:
  labels:
    name: etcdoperator
  name: etcd-operator
spec:
  replicas: 1
  selector:
    matchLabels:
      name: etcd-operator
  template:
    metadata:
      labels:
        name: etcd-operator
    spec:
      containers:
      - command:
        - etcd-operator
        - --create-crd=false
        env:
        - name: MY_POD_NAMESPACE
          valueFrom:
            fieldRef:
              apiVersion: v1
              fieldPath: metadata.namespace
        - name: MY_POD_NAME
          valueFrom:
            fieldRef:
              apiVersion: v1
              fieldPath: metadata.name
        image: quay.io/coreos/etcd-operator@sha256:c0301e4686c3ed4206e370b42de5a3bd2229b9fb4906cf85f3f30650424abec2
        imagePullPolicy: IfNotPresent
        name: etcd-operator
      serviceAccountName: etcd-operator-sa
EOF



cat > etcd-operator-cr.yaml<<EOF
apiVersion: etcd.database.coreos.com/v1beta2
kind: EtcdCluster
metadata:
  name: example-etcd-cluster
spec:
  size: 3
  version: 3.1.10
EOF


自定义的一种资源类型
    CRD的实例
	            这个实例的操作者
										实际上还是变成k8s的原有的资源
										比如deploy、sts、saemonset等等
CRD -> CR -> 由etcd的operator接管 -> 他去创建etcd集群
                 sa
				  |
				 sa和Role的绑定
				  |
				 Role