1. Operator etcd

Operator 是对 Kubernetes API 的一种扩展，支持用户定义一些 API 接口，及 CRD （customresourcedefinitions）。

etcd-Operator 能够解决一些部署和运维上的问题，例如可以自动创建高可用集群，自动化的故障恢复等。

etcd-operator 是基于 etcd 的 dns discovery 部署的集群。

1.1. 执行rbac

获取git 项目代码 https://github.com/coreos/etcd-operator/

创建 etcd-operator 及 etcd 集群运行依赖的权限信息

$ example/rbac/create_role.sh

1.2. 安装 Operator

在 default 的 namespace 中创建一个 etc-operator 的 deployment。

$ kubectl create -f example/deployment.yaml

该 deployment 会自动创建 CRD 相关的资源

$ kubectl get customresourcedefinitions
NAME                                    KIND
etcdclusters.etcd.database.coreos.com   CustomResourceDefinition.v1beta1.apiextensions.k8s.io

1.3. 创建 etcd 集群实例

有了 CRD 资源后，就可以创建出用户要使用的 etcd 集群。

$ kubectl create -f example/example-etcd-cluster.yaml

1.4. 查看集群状态

查看

$ kubectl  get pod
NAME                              READY   STATUS    RESTARTS   AGE
etcd-operator-85f7494fcf-zlsl4    1/1     Running   0          8m44s
example-etcd-cluster-ghszjmjhtk   1/1     Running   0          2m26s
example-etcd-cluster-mpfxvcwqml   1/1     Running   0          3m14s
example-etcd-cluster-qtt28lhhsg   1/1     Running   0          4m2s

查看 service

$ kubectl  get svc
NAME                          TYPE        CLUSTER-IP      EXTERNAL-IP   PORT(S)             AGE
example-etcd-cluster          ClusterIP   None            <none>        2379/TCP,2380/TCP   3d4h
example-etcd-cluster-client   ClusterIP   10.178.75.231   <none>        2379/TCP            3d4h

查看集群成员列表

$ kubectl  exec -it example-etcd-cluster-ghszjmjhtk sh

/ #  ETCDCTL_API=3 etcdctl --endpoints http://127.0.0.1:2379 member list -w table
+------------------+---------+---------------------------------+------------------------------------------------------------------------------+------------------------------------------------------------------------------+
|        ID        | STATUS  |              NAME               |                                  PEER ADDRS                                  |                                 CLIENT ADDRS                                 |
+------------------+---------+---------------------------------+------------------------------------------------------------------------------+------------------------------------------------------------------------------+
| 4fc39a0963e21b3a | started | example-etcd-cluster-mpfxvcwqml | http://example-etcd-cluster-mpfxvcwqml.example-etcd-cluster.default.svc:2380 | http://example-etcd-cluster-mpfxvcwqml.example-etcd-cluster.default.svc:2379 |
| 6c8c137284cff6a5 | started | example-etcd-cluster-ghszjmjhtk | http://example-etcd-cluster-ghszjmjhtk.example-etcd-cluster.default.svc:2380 | http://example-etcd-cluster-ghszjmjhtk.example-etcd-cluster.default.svc:2379 |
| 8aba046df47407c2 | started | example-etcd-cluster-qtt28lhhsg | http://example-etcd-cluster-qtt28lhhsg.example-etcd-cluster.default.svc:2380 | http://example-etcd-cluster-qtt28lhhsg.example-etcd-cluster.default.svc:2379 |
+------------------+---------+---------------------------------+------------------------------------------------------------------------------+------------------------------------------------------------------------------+

查看集群状态

$ kubectl  exec -it example-etcd-cluster-ghszjmjhtk sh

/ #  ETCDCTL_API=3 etcdctl --endpoints http://example-etcd-cluster-mpfxvcwqml.example-etcd-cluster.default.svc:2379,http://example-etcd-cluster-ghszjmjhtk.example-et
cd-cluster.default.svc:2379,http://example-etcd-cluster-qtt28lhhsg.example-etcd-cluster.default.svc:2379  endpoint status  -w table
+------------------------------------------------------------------------------+------------------+---------+---------+-----------+-----------+------------+
|                                   ENDPOINT                                   |        ID        | VERSION | DB SIZE | IS LEADER | RAFT TERM | RAFT INDEX |
+------------------------------------------------------------------------------+------------------+---------+---------+-----------+-----------+------------+
| http://example-etcd-cluster-mpfxvcwqml.example-etcd-cluster.default.svc:2379 | 4fc39a0963e21b3a |  3.2.13 |   25 kB |     false |        29 |          9 |
| http://example-etcd-cluster-ghszjmjhtk.example-etcd-cluster.default.svc:2379 | 6c8c137284cff6a5 |  3.2.13 |   25 kB |     false |        29 |          9 |
| http://example-etcd-cluster-qtt28lhhsg.example-etcd-cluster.default.svc:2379 | 8aba046df47407c2 |  3.2.13 |   25 kB |      true |        29 |          9 |
+------------------------------------------------------------------------------+------------------+---------+---------+-----------+-----------+------------+

注： 由于 etcd 3.2.13 版本的 endpoint status 命令没有 --cluster 参数，因此需要填写全部的 endpoints

写入数据

$ kubectl  exec -it example-etcd-cluster-ghszjmjhtk sh

/ #  ETCDCTL_API=3 etcdctl --endpoints http://example-etcd-cluster-mpfxvcwqml.example-etcd-cluster.default.svc:2379,http://example-etcd-cluster-ghszjmjhtk.example-et
cd-cluster.default.svc:2379,http://example-etcd-cluster-qtt28lhhsg.example-etcd-cluster.default.svc:2379  put operator-key operator-value
OK

读取数据

$ kubectl  exec -it example-etcd-cluster-ghszjmjhtk sh

/ #  ETCDCTL_API=3 etcdctl --endpoints http://example-etcd-cluster-mpfxvcwqml.example-etcd-cluster.default.svc:2379,http://example-etcd-cluster-ghszjmjhtk.example-et
cd-cluster.default.svc:2379,http://example-etcd-cluster-qtt28lhhsg.example-etcd-cluster.default.svc:2379  get  operator-key
operator-key
operator-value