ETCD数据的备份与恢复
一、单机备份
说明：执行etcd备份数据的恢复的机器必须和原先etcd所在机器一致
1.1、单机备份
# 使用ETCDCTL API 3
[root@minio1 ~]# export ETCDCTL_API=3
# 写入一条数据
[root@minio1 app]# ETCDCTL_API=3 etcdctl --endpoints="https://192.168.1.106:2379" --cert=/etc/etcd/ssl/etcd.pem --key=/etc/etcd/ssl/etcd-key.pem --cacert=/etc/kubernetes/pki/etcd/etcd-ca.pem put /name/1 tzh
OK
# 读取数据
[root@minio1 app]# ETCDCTL_API=3 etcdctl --endpoints="https://192.168.1.106:2379" --cert=/etc/etcd/ssl/etcd.pem --key=/etc/etcd/ssl/etcd-key.pem --cacert=/etc/kubernetes/pki/etcd/etcd-ca.pem get /name/1
/name/1
tzh
# 备份数据
[root@minio1 app]# etcdctl --endpoints="https://192.168.1.106:2379" --cert=/etc/etcd/ssl/etcd.pem --key=/etc/etcd/ssl/etcd-key.pem --cacert=/etc/kubernetes/pki/etcd/etcd-ca.pem snapshot save `date +%Y-%m-%d`-etcd_back.db
1.2、单机数据恢复
# 停止etcd服务
[root@minio1 ~]# systemctl stop etcd
# 使用ETCDCTL API 3
[root@SZD-L0105331 ~]# export ETCDCTL_API=3
# 修改etcd启动参数--data-dir指向上一步的数据恢复目录，一般在/etc/etcd/etcd文件中
# 注意--data-dir参数，恢复以后修改data-dir,再次启动etcd
[root@minio1 ~]# grep data-dir /etc/etcd/etcd.config.yml
data-dir: /var/lib/etcd
[root@minio1 ~]# etcdctl snapshot restore 2021-12-07-etcd_back.db --name=minio1 --endpoints="https://192.168.1.106:2379" --cert=/etc/etcd/ssl/etcd.pem --key=/etc/etcd/ssl/etcd-key.pem --cacert=/etc/kubernetes/pki/etcd/etcd-ca.pem --initial-cluster=minio1=https://192.168.1.106:2380 --initial-advertise-peer-urls=https://192.168.1.106:2380 --initial-cluster-token=etcd-cluster-0 --data-dir=/var/lib/etcd1
2021-12-07-etcd_back.db*********份文件名
--name**************************主机名
--endpoints*********************
--cert**************************
--key***************************
--cacert************************
--initial-cluster***************本member侧使用。描述集群中所有节点的信息，本member根据此信息去联系其他member
--initial-advertise-peer-urls***其他member使用，其他member通过该地址与本member交互信息。一定要保证从其他member能可访问该地址。静态配置方式下，该参数的value一定要同时在--initial-cluster参数中存在
--initial-cluster-token*********用于区分不同集群。本地如有多个集群要设为不同
--data-dir**********************该目录下保存了memberID，clusterID和数据等信息
# 启动etcd
[root@minio1 etcd]# systemctl start etcd
# 读取数据
[root@minio1 app]# ETCDCTL_API=3 etcdctl --endpoints="https://192.168.1.106:2379" --cert=/etc/etcd/ssl/etcd.pem --key=/etc/etcd/ssl/etcd-key.pem --cacert=/etc/kubernetes/pki/etcd/etcd-ca.pem get /name/1
/name/1
tzh
二、集群模式下的数据备份与恢复
注意：ETCD 不同的版本的 etcdctl 命令不一样，但大致差不多，本文备份使用 napshot save , 每次备份一个节点就行。
命令备份（k8s-master1 机器上备份）：
$ ETCDCTL_API=3 etcdctl --cacert=/opt/kubernetes/ssl/ca.pem --cert=/opt/kubernetes/ssl/server.pem --key=/opt/kubernetes/ssl/server-key.pem --endpoints=https://192.168.1.36:2379 snapshot save /data/etcd_backup_dir/etcd-snapshot-`date +%Y%m%d`.db
备份脚本（k8s-master1 机器上备份）：
#!/usr/bin/env bash
date;
CACERT="/opt/kubernetes/ssl/ca.pem"
CERT="/opt/kubernetes/ssl/server.pem"
EKY="/opt/kubernetes/ssl/server-key.pem"
ENDPOINTS="192.168.1.36:2379"
ETCDCTL_API=3 etcdctl \
--cacert="${CACERT}" --cert="${CERT}" --key="${EKY}" \
--endpoints=${ENDPOINTS} \
snapshot save /data/etcd_backup_dir/etcd-snapshot-`date +%Y%m%d`.db
# 备份保留30天
find /data/etcd_backup_dir/ -name *.db -mtime +30 -exec rm -f {} \;
恢复
准备工作
- 停止所有 Master 上
kube-apiserver服务
$ systemctl stop kube-apiserver
# 确认 kube-apiserver 服务是否停止
$ ps -ef | grep kube-apiserver
- 停止集群中所有 ETCD 服务
$ systemctl stop etcd
- 移除所有 ETCD 存储目录下数据
$ mv /var/lib/etcd/default.etcd /var/lib/etcd/default.etcd.bak
- 拷贝 ETCD 备份快照
# 从 k8s-master1 机器上拷贝备份
$ scp /data/etcd_backup_dir/etcd-snapshot-20191222.db root@k8s-master2:/data/etcd_backup_dir/
$ scp /data/etcd_backup_dir/etcd-snapshot-20191222.db root@k8s-master3:/data/etcd_backup_dir/
恢复备份
# k8s-master1 机器上操作
$ ETCDCTL_API=3 etcdctl snapshot restore /data/etcd_backup_dir/etcd-snapshot-20191222.db \
--name etcd-0 \
--initial-cluster "etcd-0=https://192.168.1.36:2380,etcd-1=https://192.168.1.37:2380,etcd-2=https://192.168.1.38:2380" \
--initial-cluster-token etcd-cluster \
--initial-advertise-peer-urls https://192.168.1.36:2380 \
--data-dir=/var/lib/etcd/default.etcd
# k8s-master2 机器上操作
$ ETCDCTL_API=3 etcdctl snapshot restore /data/etcd_backup_dir/etcd-snapshot-20191222.db \
--name etcd-1 \
--initial-cluster "etcd-0=https://192.168.1.36:2380,etcd-1=https://192.168.1.37:2380,etcd-2=https://192.168.1.38:2380" \
--initial-cluster-token etcd-cluster \
--initial-advertise-peer-urls https://192.168.1.37:2380 \
--data-dir=/var/lib/etcd/default.etcd
# k8s-master3 机器上操作
$ ETCDCTL_API=3 etcdctl snapshot restore /data/etcd_backup_dir/etcd-snapshot-20191222.db \
--name etcd-2 \
--initial-cluster "etcd-0=https://192.168.1.36:2380,etcd-1=https://192.168.1.37:2380,etcd-2=https://192.168.1.38:2380" \
--initial-cluster-token etcd-cluster \
--initial-advertise-peer-urls https://192.168.1.38:2380 \
--data-dir=/var/lib/etcd/default.etcd
上面三台 ETCD 都恢复完成后，依次登陆三台机器启动 ETCD
$ systemctl start etcd
三台 ETCD 启动完成，检查 ETCD 集群状态
$ ETCDCTL_API=3 etcdctl --cacert=/opt/kubernetes/ssl/ca.pem --cert=/opt/kubernetes/ssl/server.pem --key=/opt/kubernetes/ssl/server-key.pem --endpoints=https://192.168.1.36:2379,https://192.168.1.37:2379,https://192.168.1.38:2379 endpoint health
三台 ETCD 全部健康，分别到每台 Master 启动 kube-apiserver
$ systemctl start kube-apiserver
检查 Kubernetes 集群是否恢复正常
$ kubectl get cs
总结：
Kubernetes 集群备份主要是备份 ETCD 集群。而恢复时，主要考虑恢复整个顺序：
停止kube-apiserver --> 停止ETCD --> 恢复数据 --> 启动ETCD --> 启动kube-apiserve
注意：备份ETCD集群时，只需要备份一个ETCD就行，恢复时，拿同一份备份数据恢复
原文链接：https://zhuanlan.zhihu.com/p/101523337