ETCD 基本操作

##　备份数据

ETCDCTL_API=3 etcdctl --endpoints=https://127.0.0.1:2379 --cacert=/etc/kubernetes/pki/etcd/ca.crt --cert=/etc/kubernetes/pki/etcd/server.crt --key=/etc/kubernetes/pki/etcd/server.key snapshot save /var/lib/etcd/snapshot-20220810.db
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成员操作

1 查看成员

etcdctl --endpoints=https://127.0.0.1:2379 --cacert=/etc/kubernetes/pki/etcd/ca.crt --cert=/etc/kubernetes/pki/etcd/server.crt --key=/etc/kubernetes/pki/etcd/server.key member list
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2 移除成员

etcdctl --endpoints=https://127.0.0.1:2379 --cacert=/etc/kubernetes/pki/etcd/ca.crt --cert=/etc/kubernetes/pki/etcd/server.crt --key=/etc/kubernetes/pki/etcd/server.key member remove 成员ID
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实例：

sh-5.1# etcdctl --endpoints=https://127.0.0.1:2379 --cacert=/etc/kubernetes/pki/etcd/ca.crt --cert=/etc/kubernetes/pki/etcd/server.crt --key=/etc/kubernetes/pki/etcd/server.key member list
73478d5cdc15edb2, started, k8s-master2.prod, https://192.168.0.225:2380, https://192.168.0.225:2379, false
eb5c182940e3a951, started, k8s-master1.prod, https://192.168.0.185:2380, https://192.168.0.185:2379, false
sh-5.1# etcdctl --endpoints=https://127.0.0.1:2379 --cacert=/etc/kubernetes/pki/etcd/ca.crt --cert=/etc/kubernetes/pki/etcd/server.crt --key=/etc/kubernetes/pki/etcd/server.key member remove 73478d5cdc15edb2
Member 73478d5cdc15edb2 removed from cluster c51f1c2e3181e84f
sh-5.1# etcdctl --endpoints=https://127.0.0.1:2379 --cacert=/etc/kubernetes/pki/etcd/ca.crt --cert=/etc/kubernetes/pki/etcd/server.crt --key=/etc/kubernetes/pki/etcd/server.key member list
eb5c182940e3a951, started, k8s-master1.prod, https://192.168.0.185:2380, https://192.168.0.185:2379, false
sh-5.1#

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如何从备份的文件中恢复数据

1 去除备份文件中原有的元数据

因为备份的文件是从原来的集群中备份的，里面有原来集群中的元数据，这些元数据里面有集群的成员信息，如果不清空，在恢复的时候，由于其他成员不在线，就好恢复失败，除非其他成员也在线。

如下示例假设不论之前有多少集群成员，目前只需要一个，可以进行如下操作

删除宿主机目录 /var/lib/etcd/member ，之后把备份的文件复制到 /var/lib/etcd/ 目录下，因为 k8s 集群中的 etcd 默认挂载目录就是
/var/lib/etcd:/var/lib/etcd

rm -rf /var/lib/etcd/member
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之后，使用原有 etcd 同样的镜像并挂载 /var/lib/etcd 目录到容器的 /var/lib/etcd，运行容器，让产生去除元数据后的数据文件。
具体命令如下:

#　运行容器，并进入容器
docker run -it --rm --network host -v /var/lib/etcd:/var/lib/etcd k8s.gcr.io/etcd:3.5.1-0 sh
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＃在容器内执行如下命令:
cd /var/lib/etcd

ETCDCTL_API=3 etcdctl snapshot restore snapshot.db \
  --name 本机的主机名 \
  --initial-cluster 本机的主机名=http://本机ip:2380 \
  --initial-cluster-token etcd-cluster-1 \
  --initial-advertise-peer-urls http://本机ip:2380
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退出 容器，并检查宿主机的 /var/lib/etcd 目录下是否有 member 目录

3 启动新的 etcd

如果是 k8s，修改etcd的 yaml 文件/etc/kubernetes/manifests/etcd.yaml
修改之前可能有其他的ip信息存在，或者可能有集群状态的参数如下图:

去掉非本机的 IP信息，并且删除集群状态的配置（紫色框的内容），这样可以实现单机运行 etcd，并且保留了原有的数据，之后再根据需要，再加入其他节点即可恢复完成。
修改后如下图：

重启 kubelet 服务

systemctl restart kubelet
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检查 容器是否启动

docker ps |grep etcd
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生成 证书（这个有坑，别在生产上实操，目前还没解决）

备份原来的证书，并删除原来的证书

cp -ra /etc/kubernetes/pki{,.bak}
ls /etc/kubernetes/

find /etc/kubernetes/pki -type f |xargs rm -rf
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帮助信息

kubeadm init phase certs --help
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This command is not meant to be run on its own. See list of available subcommands.

Usage:
  kubeadm init phase certs [flags]
  kubeadm init phase certs [command]

Available Commands:
  all                      Generate all certificates
  apiserver                Generate the certificate for serving the Kubernetes API
  apiserver-etcd-client    Generate the certificate the apiserver uses to access etcd
  apiserver-kubelet-client Generate the certificate for the API server to connect to kubelet
  ca                       Generate the self-signed Kubernetes CA to provision identities for other Kubernetes components
  etcd-ca                  Generate the self-signed CA to provision identities for etcd
  etcd-healthcheck-client  Generate the certificate for liveness probes to healthcheck etcd
  etcd-peer                Generate the certificate for etcd nodes to communicate with each other
  etcd-server              Generate the certificate for serving etcd
  front-proxy-ca           Generate the self-signed CA to provision identities for front proxy
  front-proxy-client       Generate the certificate for the front proxy client
  sa                       Generate a private key for signing service account tokens along with its public key

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生成新的证书

kubeadm init phase certs all --apiserver-cert-extra-sans kube-apiserver,192.168.0.225,192.168.0.128,192.168.0.100 --control-plane-endpoint kube-apiserver
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配置

备份

cp -ra /etc/kubernetes{,.bak}
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删除原有的配置文件

rm -rf /etc/kubernetes/*.conf
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重新生成

kubeadm init phase kubeconfig all
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复制管理员配置文件

\cp /etc/kubernetes/admin.conf ~/.kube/config
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重启 kubelet 服务

systemctl restart kubelet
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删除原有的容器

docker rm -f `docker ps  |awk '$NF ~ /^k8s/{print $1}'`
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