目录
一.系统环境
| 服务器版本 | docker软件版本 | CPU架构 |
|---|---|---|
| CentOS Linux release 7.4.1708 (Core) | Docker version 20.10.12 | x86_64 |
二.前言
etcd 是兼顾一致性与高可用性的键值对数据库，可以作为保存 Kubernetes 所有集群数据的后台数据库。保持 etcd 集群的稳定对 Kubernetes 集群的稳定性至关重要。
三.etcd数据库
3.1 概述
etcd是使用Go语言开发的一个开源的、高可用的分布式key-value存储系统，可以用于配置共享和服务的注册和发现。类似项目有zookeeper和consul。
etcd具有以下特点：
- 完全复制：集群中的每个节点都可以使用完整的存档
- 高可用性：Etcd可用于避免硬件的单点故障或网络问题
- 一致性：每次读取都会返回跨多主机的最新写入
- 简单：包括一个定义良好、面向用户的API（gRPC）
- 安全：实现了带有可选的客户端证书身份验证的自动化TLS
- 快速：每秒10000次写入的基准速度
- 可靠：使用Raft算法实现了强一致、高可用的服务存储目录
Kubernetes 集群对etcd集群有几点要求：
- 运行的 etcd 集群个数成员为奇数。
- etcd 是一个 leader-based 分布式系统。确保主节点定期向所有从节点发送心跳，以保持集群稳定。
- 确保不发生资源不足：集群的性能和稳定性对网络和磁盘 I/O 非常敏感。任何资源匮乏都会导致心跳超时， 从而导致集群的不稳定。不稳定的情况表明没有选出任何主节点。 在这种情况下，集群不能对其当前状态进行任何更改，这意味着不能调度新的 Pod。
- 保持 etcd 集群的稳定对 Kubernetes 集群的稳定性至关重要。 因此，请在专用机器或隔离环境上运行 etcd 集群， 以满足所需资源需求。
- 在生产中运行的 etcd 的最低推荐版本是 3.2.10+。
四.安装部署etcd单节点
4.1 环境介绍
首先安装etcd单节点，etcd架构：etcd1机器作为etcd的服务端，etcd2机器作为客户端访问
| 服务器 | 操作系统版本 | CPU架构 | 进程 | 功能描述 |
|---|---|---|---|---|
| etcd1/192.168.110.133 | CentOS Linux release 7.4.1708 (Core) | x86_64 | etcd | etcd服务端 |
| etcd2/192.168.110.131 | CentOS Linux release 7.4.1708 (Core) | x86_64 | etcd | etcd客户端 |
4.2 配置节点的基本环境
先配置节点的基本环境，所有节点都要同时设置，在此以etcd1作为示例
首先设置主机名
[root@localhost ~]# cat /etc/hostname etcd1 配置IP地址（可选）
[root@localhost ~]# vim /etc/sysconfig/network-scripts/ifcfg-ens32 [root@localhost ~]# cat /etc/sysconfig/network-scripts/ifcfg-ens32 TYPE=Ethernet BOOTPROTO=static NAME=ens32 DEVICE=ens32 ONBOOT=yes DNS1=114.114.114.114 IPADDR=192.168.110.133 NETMASK=255.255.255.0 GATEWAY=192.168.110.2 ZONE=trusted #重启网卡 [root@localhost ~]# service network restart Restarting network (via systemctl): [ 确定 ] [root@localhost ~]# systemctl restart NetworkManager 重启机器之后看是否能访问网络
[root@etcd1 ~]# ping www.baidu.com PING www.a.shifen.com (14.215.177.38) 56(84) bytes of data. 64 bytes from 14.215.177.38 (14.215.177.38): icmp_seq=1 ttl=128 time=31.1 ms 64 bytes from 14.215.177.38 (14.215.177.38): icmp_seq=2 ttl=128 time=30.5 ms 64 bytes from 14.215.177.38 (14.215.177.38): icmp_seq=3 ttl=128 time=31.9 ms 64 bytes from 14.215.177.38 (14.215.177.38): icmp_seq=4 ttl=128 time=30.6 ms ^C --- www.a.shifen.com ping statistics --- 4 packets transmitted, 4 received, 0% packet loss, time 3007ms rtt min/avg/max/mdev = 30.593/31.075/31.926/0.533 ms 配置IP和主机名映射
[root@etcd1 ~]# vim /etc/hosts [root@etcd1 ~]# cat /etc/hosts 127.0.0.1 localhost localhost.localdomain localhost4 localhost4.localdomain4 ::1 localhost localhost.localdomain localhost6 localhost6.localdomain6 192.168.110.133 etcd1 192.168.110.131 etcd2 192.168.110.132 etcd3 复制到另外两个主机
[root@etcd1 ~]# scp /etc/hosts etcd3:/etc/hosts root@etcd3's password: hosts 100% 224 281.3KB/s 00:00 [root@etcd1 ~]# scp /etc/hosts etcd2:/etc/hosts root@etcd2's password: hosts 100% 224 218.1KB/s 00:00 能相互ping通则正常
[root@etcd1 ~]# ping etcd1 PING etcd1 (192.168.110.133) 56(84) bytes of data. 64 bytes from etcd1 (192.168.110.133): icmp_seq=1 ttl=64 time=0.029 ms 64 bytes from etcd1 (192.168.110.133): icmp_seq=2 ttl=64 time=0.033 ms 64 bytes from etcd1 (192.168.110.133): icmp_seq=3 ttl=64 time=0.043 ms ^C --- etcd1 ping statistics --- 3 packets transmitted, 3 received, 0% packet loss, time 2002ms rtt min/avg/max/mdev = 0.029/0.035/0.043/0.005 ms [root@etcd1 ~]# ping etcd2 PING etcd2 (192.168.110.131) 56(84) bytes of data. 64 bytes from etcd2 (192.168.110.131): icmp_seq=1 ttl=64 time=1.61 ms 64 bytes from etcd2 (192.168.110.131): icmp_seq=2 ttl=64 time=1.92 ms ^C --- etcd2 ping statistics --- 2 packets transmitted, 2 received, 0% packet loss, time 1010ms rtt min/avg/max/mdev = 1.612/1.769/1.926/0.157 ms [root@etcd1 ~]# ping etcd3 PING etcd3 (192.168.110.132) 56(84) bytes of data. 64 bytes from etcd3 (192.168.110.132): icmp_seq=1 ttl=64 time=0.484 ms 64 bytes from etcd3 (192.168.110.132): icmp_seq=2 ttl=64 time=2.65 ms 64 bytes from etcd3 (192.168.110.132): icmp_seq=3 ttl=64 time=2.65 ms ^C --- etcd3 ping statistics --- 3 packets transmitted, 3 received, 0% packet loss, time 2021ms rtt min/avg/max/mdev = 0.484/1.931/2.657/1.023 ms 关闭屏保（可选）
[root@etcd1 ~]# setterm -blank 0 配置yum源
[root@etcd1 ~]# rm -rf /etc/yum.repos.d/* ;wget ftp://ftp.rhce.cc/k8s/* -P /etc/yum.repos.d/ 关闭selinux
[root@etcd1 ~]# cat /etc/selinux/config # This file controls the state of SELinux on the system. # SELINUX= can take one of these three values: # enforcing - SELinux security policy is enforced. # permissive - SELinux prints warnings instead of enforcing. # disabled - No SELinux policy is loaded. SELINUX=disabled # SELINUXTYPE= can take one of three two values: # targeted - Targeted processes are protected, # minimum - Modification of targeted policy. Only selected processes are protected. # mls - Multi Level Security protection. SELINUXTYPE=targeted [root@etcd1 ~]# getenforce Disabled 配置防火墙允许所有数据通过
[root@etcd1 ~]# firewall-cmd --set-default-zone=trusted Warning: ZONE_ALREADY_SET: trusted success [root@etcd1 ~]# firewall-cmd --get-default-zone trusted 4.3 安装部署etcd单节点
etcd1机器安装etcd
[root@etcd1 ~]# yum -y install etcd etcd的配置文件为/etc/etcd/etcd.conf ,注释如下：
[root@etcd1 ~]# vim /etc/etcd/etcd.conf #配置文件简单注释：etcd节点间通信端口2380，客户端访问etcd的端口为2379 #数据目录：ETCD_DATA_DIR="/var/lib/etcd/default.etcd [root@etcd1 ~]# cat /etc/etcd/etcd.conf | egrep -v "^#|^$" ETCD_DATA_DIR="/var/lib/etcd/default.etcd" #ETCD_LISTEN_PEER_URLS="http://localhost:2380" ETCD_LISTEN_CLIENT_URLS="http://localhost:2379" #etcd名字 ETCD_NAME="default" 修改配置文件如下，添加etcd1的IP和端口
[root@etcd1 ~]# vim /etc/etcd/etcd.conf [root@etcd1 ~]# cat /etc/etcd/etcd.conf ETCD_DATA_DIR="/var/lib/etcd/default.etcd" ETCD_LISTEN_PEER_URLS="http://192.168.110.133:2380,http://localhost:2380" ETCD_LISTEN_CLIENT_URLS="http://192.168.110.133:2379,http://localhost:2379" ETCD_NAME="default" #[Clustering] ETCD_ADVERTISE_CLIENT_URLS="http://localhost:2379" 启动etcd
[root@etcd1 ~]# systemctl enable etcd --now Created symlink from /etc/systemd/system/multi-user.target.wants/etcd.service to /usr/lib/systemd/system/etcd.service. [root@etcd1 ~]# systemctl status etcd ● etcd.service - Etcd Server Loaded: loaded (/usr/lib/systemd/system/etcd.service; enabled; vendor preset: disabled) Active: active (running) since 一 2022-01-10 22:53:13 CST; 9s ago Main PID: 1148 (etcd) CGroup: /system.slice/etcd.service └─1148 /usr/bin/etcd --name=default --data-dir=/var/lib/etcd/default.etcd --listen-client-urls=http://192.168.110.133:2379,http://localhost:2379 1月 10 22:53:13 etcd1 etcd[1148]: raft.node: 8e9e05c52164694d elected leader 8e9e05c52164694d at term 2 1月 10 22:53:13 etcd1 etcd[1148]: setting up the initial cluster version to 3.3 1月 10 22:53:13 etcd1 etcd[1148]: published {Name:default ClientURLs:[http://localhost:2379]} to cluster cdf818194e3a8c32 1月 10 22:53:13 etcd1 etcd[1148]: set the initial cluster version to 3.3 1月 10 22:53:13 etcd1 etcd[1148]: enabled capabilities for version 3.3 1月 10 22:53:13 etcd1 etcd[1148]: ready to serve client requests 1月 10 22:53:13 etcd1 etcd[1148]: ready to serve client requests 1月 10 22:53:13 etcd1 etcd[1148]: serving insecure client requests on 127.0.0.1:2379, this is strongly discouraged! 1月 10 22:53:13 etcd1 etcd[1148]: serving insecure client requests on 192.168.110.133:2379, this is strongly discouraged! 1月 10 22:53:13 etcd1 systemd[1]: Started Etcd Server. 查看etcd的成员，查看有几个节点
[root@etcd1 ~]# etcdctl member list 8e9e05c52164694d: name=default peerURLs=http://localhost:2380 clientURLs=http://localhost:2379 isLeader=true 查看集群健康状态
[root@etcd1 ~]# etcdctl cluster-health member 8e9e05c52164694d is healthy: got healthy result from http://localhost:2379 cluster is healthy 4.4 使用客户端访问etcd服务
现在etcd2机器作为客户端访问etcd1机器上的etcd服务
首先etcd2机器安装etcd
[root@etcd2 ~]# yum -y install etcd 查看etcdctl的帮助
[root@etcd2 ~]# etcdctl --help 连接192.168.110.133上的etcd服务，发现拒绝
[root@etcd2 ~]# etcdctl --endpoints http://192.168.110.133:2379 ls / Error: client: etcd cluster is unavailable or misconfigured; error #0: dial tcp [::1]:2379: connect: connection refused error #0: dial tcp [::1]:2379: connect: connection refused 修改etcd1上的配置文件ETCD_ADVERTISE_CLIENT_URLS="http://192.168.110.133:2379,http://localhost:2379"，并重启etcd服务
[root@etcd1 ~]# cat /etc/etcd/etcd.conf | egrep -v "^#|^$" ETCD_DATA_DIR="/var/lib/etcd/default.etcd" ETCD_LISTEN_PEER_URLS="http://192.168.110.133:2380,http://localhost:2380" ETCD_LISTEN_CLIENT_URLS="http://192.168.110.133:2379,http://localhost:2379" ETCD_NAME="default" ETCD_ADVERTISE_CLIENT_URLS="http://192.168.110.133:2379,http://localhost:2379" #重启 [root@etcd1 ~]# systemctl restart etcd [root@etcd1 ~]# systemctl status etcd 此时客户端连接192.168.110.133成功，ls /表示查询根目录下内容
[root@etcd2 ~]# etcdctl --endpoints http://192.168.110.133:2379 ls / 4.4.1 使用2版本API管理etcd
etcd写入数据的时候有两个版本：2版本和3版本，默认是2版本，Set environment variable ETCDCTL_API=3 to use v3 API or ETCDCTL_API=2 to use v2 API
现在还没有数据
[root@etcd1 ~]# etcdctl ls / etcd1创建数据
[root@etcd1 ~]# etcdctl mkdir /comeon [root@etcd1 ~]# etcdctl ls / /comeon 客户端连接也可以看到数据
[root@etcd2 ~]# etcdctl --endpoints http://192.168.110.133:2379 ls / /comeon 删除数据
[root@etcd1 ~]# etcdctl rmdir /comeon [root@etcd1 ~]# etcdctl ls / 4.4.2 使用3版本API管理etcd
现在使用3版本的API
[root@etcd1 ~]# export ETCDCTL_API=3 设置为3版本的API之后，help显示的内容也会不同
[root@etcd1 ~]# etcdctl --help NAME: etcdctl - A simple command line client for etcd3. USAGE: etcdctl VERSION: 3.3.11 API VERSION: 3.3 COMMANDS: get Gets the key or a range of keys put Puts the given key into the store del Removes the specified key or range of keys [key, range_end) txn Txn processes all the requests in one transaction compaction Compacts the event history in etcd alarm disarm Disarms all alarms alarm list Lists all alarms defrag Defragments the storage of the etcd members with given endpoints endpoint health Checks the healthiness of endpoints specified in `--endpoints` flag endpoint status Prints out the status of endpoints specified in `--endpoints` flag endpoint hashkv Prints the KV history hash for each endpoint in --endpoints move-leader Transfers leadership to another etcd cluster member. watch Watches events stream on keys or prefixes version Prints the version of etcdctl lease grant Creates leases lease revoke Revokes leases lease timetolive Get lease information lease list List all active leases lease keep-alive Keeps leases alive (renew) member add Adds a member into the cluster member remove Removes a member from the cluster member update Updates a member in the cluster member list Lists all members in the cluster snapshot save Stores an etcd node backend snapshot to a given file snapshot restore Restores an etcd member snapshot to an etcd directory snapshot status Gets backend snapshot status of a given file make-mirror Makes a mirror at the destination etcd cluster migrate Migrates keys in a v2 store to a mvcc store lock Acquires a named lock elect Observes and participates in leader election auth enable Enables authentication auth disable Disables authentication user add Adds a new user user delete Deletes a user user get Gets detailed information of a user user list Lists all users user passwd Changes password of user user grant-role Grants a role to a user user revoke-role Revokes a role from a user role add Adds a new role role delete Deletes a role role get Gets detailed information of a role role list Lists all roles role grant-permission Grants a key to a role role revoke-permission Revokes a key from a role check perf Check the performance of the etcd cluster help Help about any command ...... -w, --write-out="simple" set the output format (fields, json, protobuf, simple, table) 写数据
[root@etcd1 ~]# etcdctl put student1 99 OK 查数据
[root@etcd1 ~]# etcdctl get student1 student1 99 注意：2版本API和3版本API不可互用，从k8s1.5版本，etcd就开始使用3版本往etcd里写数据
[root@etcd2 ~]# export ETCDCTL_API=3 [root@etcd2 ~]# etcdctl --endpoints http://192.168.110.133:2379 get student1 student1 99 etcd单节点搭建完毕，接下来添加两个节点变为etcd集群。
五.安装部署etcd集群
5.1 环境介绍
etcd集群架构：etcd1为leader，etcd2为follower，etcd3为follower
| 服务器 | 操作系统版本 | CPU架构 | 进程 | 功能描述 |
|---|---|---|---|---|
| etcd1/192.168.110.133 | CentOS Linux release 7.4.1708 (Core) | x86_64 | etcd | leader |
| etcd2/192.168.110.131 | CentOS Linux release 7.4.1708 (Core) | x86_64 | etcd | follower |
| etcd3/192.168.110.132 | CentOS Linux release 7.4.1708 (Core) | x86_64 | etcd | follower |
5.2 把etcd2机器加入集群
首先还原环境变量
[root@etcd1 ~]# unset ETCDCTL_API 停止etcd1机器的etcd服务
[root@etcd1 ~]# systemctl stop etcd [root@etcd1 ~]# systemctl status etcd ● etcd.service - Etcd Server Loaded: loaded (/usr/lib/systemd/system/etcd.service; enabled; vendor preset: disabled) Active: inactive (dead) since 二 2022-01-11 15:21:30 CST; 49s ago Process: 1582 ExecStart=/bin/bash -c GOMAXPROCS=$(nproc) /usr/bin/etcd --name="${ETCD_NAME}" --data-dir="${ETCD_DATA_DIR}" --listen-client-urls="${ETCD_LISTEN_CLIENT_URLS}" (code=killed, signal=TERM) Main PID: 1582 (code=killed, signal=TERM) 查看etcd的数据目录
[root@etcd1 ~]# cat /etc/etcd/etcd.conf | grep -i data ETCD_DATA_DIR="/var/lib/etcd/default.etcd" 删除原始数据
[root@etcd1 ~]# rm -rf /var/lib/etcd/* 修改配置文件，把etcd2机器加入配置
[root@etcd1 ~]# vim /etc/etcd/etcd.conf [root@etcd1 ~]# cat /etc/etcd/etcd.conf | egrep -v "^#|^$" #配置数据目录 ETCD_DATA_DIR="/var/lib/etcd/cluster.etcd" ETCD_LISTEN_PEER_URLS="http://192.168.110.133:2380,http://localhost:2380" ETCD_LISTEN_CLIENT_URLS="http://192.168.110.133:2379,http://localhost:2379" ETCD_NAME="etcd133" ETCD_INITIAL_ADVERTISE_PEER_URLS="http://192.168.110.133:2380" ETCD_ADVERTISE_CLIENT_URLS="http://192.168.110.133:2379,http://localhost:2379" #目前是两个节点，所以这里是两个节点的etcd ETCD_INITIAL_CLUSTER="etcd133=http://192.168.110.133:2380,etcd131=http://192.168.110.131:2380" #集群token ETCD_INITIAL_CLUSTER_TOKEN="etcd-cluster" #新创建etcd集群的时候ETCD_INITIAL_CLUSTER_STATE="new"，往已经存在的etcd集群添加etcd节点时：ETCD_INITIAL_CLUSTER_STATE="existing" ETCD_INITIAL_CLUSTER_STATE="new" 复制配置文件到etcd2
[root@etcd1 ~]# scp /etc/etcd/etcd.conf etcd2:/etc/etcd/etcd.conf root@etcd2's password: etcd.conf 100% 1813 1.7MB/s 00:00 etcd2机器修改配置文件
[root@etcd2 ~]# unset ETCDCTL_API [root@etcd2 ~]# vim /etc/etcd/etcd.conf [root@etcd2 ~]# cat /etc/etcd/etcd.conf | egrep -v "^#|^$" ETCD_DATA_DIR="/var/lib/etcd/cluster.etcd" ETCD_LISTEN_PEER_URLS="http://192.168.110.131:2380,http://localhost:2380" ETCD_LISTEN_CLIENT_URLS="http://192.168.110.131:2379,http://localhost:2379" ETCD_NAME="etcd131" ETCD_INITIAL_ADVERTISE_PEER_URLS="http://192.168.110.131:2380" ETCD_ADVERTISE_CLIENT_URLS="http://192.168.110.131:2379,http://localhost:2379" ETCD_INITIAL_CLUSTER="etcd133=http://192.168.110.133:2380,etcd131=http://192.168.110.131:2380" ETCD_INITIAL_CLUSTER_TOKEN="etcd-cluster" ETCD_INITIAL_CLUSTER_STATE="new" 两个节点都启动etcd
[root@etcd1 ~]# systemctl start etcd [root@etcd1 ~]# systemctl status etcd [root@etcd2 ~]# systemctl enable etcd --now Created symlink from /etc/systemd/system/multi-user.target.wants/etcd.service to /usr/lib/systemd/system/etcd.service. [root@etcd2 ~]# systemctl status etcd 查看etcd集群成员，可以看到192.168.110.133节点是Leader
[root@etcd1 ~]# etcdctl member list 341a3c460c1c993a: name=etcd131 peerURLs=http://192.168.110.131:2380 clientURLs=http://192.168.110.131:2379,http://localhost:2379 isLeader=false ab23bcc86cf3190b: name=etcd133 peerURLs=http://192.168.110.133:2380 clientURLs=http://192.168.110.133:2379,http://localhost:2379 isLeader=true 集群健康状态
[root@etcd1 ~]# etcdctl cluster-health member 341a3c460c1c993a is healthy: got healthy result from http://192.168.110.131:2379 member ab23bcc86cf3190b is healthy: got healthy result from http://192.168.110.133:2379 cluster is healthy 现在两个节点的etcd集群搭建完毕，数据也同步了
[root@etcd1 ~]# etcdctl ls / [root@etcd1 ~]# etcdctl mkdir /public [root@etcd1 ~]# export ETCDCTL_API=3 [root@etcd1 ~]# etcdctl put student1 59 OK [root@etcd2 ~]# etcdctl ls / /public [root@etcd2 ~]# export ETCDCTL_API=3 [root@etcd2 ~]# etcdctl get student1 student1 59 5.3 把etcd3机器加入集群
现在添加一个节点etcd3到集群
etcd3安装etcd
[root@etcd3 ~]# yum -y install etcd 加入新节点的时候，使用API2版本
[root@etcd1 ~]# export ETCDCTL_API=2 执行添加节点命令，注意：ETCD_INITIAL_CLUSTER_STATE="existing"
[root@etcd1 ~]# etcdctl member add etcd132 http://192.168.110.132:2380 Added member named etcd132 with ID 7d816f4fa2bea295 to cluster ETCD_NAME="etcd132" ETCD_INITIAL_CLUSTER="etcd131=http://192.168.110.131:2380,etcd132=http://192.168.110.132:2380,etcd133=http://192.168.110.133:2380" ETCD_INITIAL_CLUSTER_STATE="existing" 查看集群成员，发现192.168.110.132显示不正常
[root@etcd1 ~]# etcdctl member list 341a3c460c1c993a: name=etcd131 peerURLs=http://192.168.110.131:2380 clientURLs=http://192.168.110.131:2379,http://localhost:2379 isLeader=false 7d816f4fa2bea295[unstarted]: peerURLs=http://192.168.110.132:2380 ab23bcc86cf3190b: name=etcd133 peerURLs=http://192.168.110.133:2380 clientURLs=http://192.168.110.133:2379,http://localhost:2379 isLeader=true 复制配置文件到etcd3
[root@etcd1 ~]# scp /etc/etcd/etcd.conf etcd3:/etc/etcd/etcd.conf root@etcd3's password: etcd.conf 100% 1813 1.1MB/s 00:00 etcd3修改配置文件
#注意：添加到一个已经存在的集群，etcd133和etcd131配置文件不变，只修改etcd132配置文件 [root@etcd3 ~]# vim /etc/etcd/etcd.conf [root@etcd3 ~]# cat /etc/etcd/etcd.conf | egrep -v "^#|^$" ETCD_DATA_DIR="/var/lib/etcd/cluster.etcd" ETCD_LISTEN_PEER_URLS="http://192.168.110.132:2380,http://localhost:2380" ETCD_LISTEN_CLIENT_URLS="http://192.168.110.132:2379,http://localhost:2379" ETCD_NAME="etcd132" ETCD_INITIAL_ADVERTISE_PEER_URLS="http://192.168.110.132:2380" ETCD_ADVERTISE_CLIENT_URLS="http://192.168.110.132:2379,http://localhost:2379" ETCD_INITIAL_CLUSTER="etcd133=http://192.168.110.133:2380,etcd131=http://192.168.110.131:2380,etcd132=http://192.168.110.132:2380" ETCD_INITIAL_CLUSTER_TOKEN="etcd-cluster" ETCD_INITIAL_CLUSTER_STATE="existing" etcd3启动etcd
[root@etcd3 ~]# systemctl enable etcd --now Created symlink from /etc/systemd/system/multi-user.target.wants/etcd.service to /usr/lib/systemd/system/etcd.service. 查看etcd集群成员，etcd集群有三个节点了
[root@etcd1 ~]# etcdctl member list 341a3c460c1c993a: name=etcd131 peerURLs=http://192.168.110.131:2380 clientURLs=http://192.168.110.131:2379,http://localhost:2379 isLeader=false 7d816f4fa2bea295: name=etcd132 peerURLs=http://192.168.110.132:2380 clientURLs=http://192.168.110.132:2379,http://localhost:2379 isLeader=false ab23bcc86cf3190b: name=etcd133 peerURLs=http://192.168.110.133:2380 clientURLs=http://192.168.110.133:2379,http://localhost:2379 isLeader=true 自此etcd集群搭建完毕，接下来进行etcd服务的管理。
六.etcd做快照备份数据
生产环境中，有些重要数据是要备份的，以免造成数据丢失。etcd对数据做快照可以进行数据备份。
设置API版本为3
[root@etcd1 ~]# export ETCDCTL_API=3 为了避免数据丢失，可以进行数据备份，即数据做快照，数据快照的help如下
[root@etcd1 ~]# etcdctl snap --help NAME: snapshot - Manages etcd node snapshots USAGE: etcdctl snapshot <subcommand> API VERSION: 3.3 COMMANDS: save Stores an etcd node backend snapshot to a given file restore Restores an etcd member snapshot to an etcd directory status Gets backend snapshot status of a given file GLOBAL OPTIONS: --cacert="" verify certificates of TLS-enabled secure servers using this CA bundle --cert="" identify secure client using this TLS certificate file --command-timeout=5s timeout for short running command (excluding dial timeout) --debug[=false] enable client-side debug logging --dial-timeout=2s dial timeout for client connections -d, --discovery-srv="" domain name to query for SRV records describing cluster endpoints --endpoints=[127.0.0.1:2379] gRPC endpoints --hex[=false] print byte strings as hex encoded strings --insecure-discovery[=true] accept insecure SRV records describing cluster endpoints --insecure-skip-tls-verify[=false] skip server certificate verification --insecure-transport[=true] disable transport security for client connections --keepalive-time=2s keepalive time for client connections --keepalive-timeout=6s keepalive timeout for client connections --key="" identify secure client using this TLS key file --user="" username[:password] for authentication (prompt if password is not supplied) -w, --write-out="simple" set the output format (fields, json, protobuf, simple, table) 进行快照
[root@etcd1 ~]# etcdctl snap save student.data Snapshot saved at student.data 七.etcd恢复数据
删除数据使用快照进行恢复
[root@etcd1 ~]# etcdctl del student1 1 [root@etcd1 ~]# etcdctl del student2 1 [root@etcd1 ~]# etcdctl get student1 [root@etcd1 ~]# etcdctl get student2 使用快照恢复数据的时候需要把快照复制到其他节点
[root@etcd1 ~]# scp student.data etcd2:~/ root@etcd2's password: student.data 100% 20KB 14.5MB/s 00:00 [root@etcd1 ~]# scp student.data etcd3:~/ root@etcd3's password: student.data 100% 20KB 8.1MB/s 00:00 在所有节点停止etcd并清空数据
[root@etcd1 ~]# systemctl stop etcd [root@etcd1 ~]# rm -rf /var/lib/etcd/* [root@etcd1 ~]# chown etcd:etcd student.data [root@etcd2 ~]# systemctl stop etcd [root@etcd2 ~]# rm -rf /var/lib/etcd/* [root@etcd2 ~]# chown etcd:etcd student.data [root@etcd3 ~]# systemctl stop etcd [root@etcd3 ~]# rm -rf /var/lib/etcd/* [root@etcd3 ~]# chown etcd:etcd student.data 在每个节点上使用快照恢复数据
[root@etcd1 ~]# etcdctl snapshot restore student.data --name etcd133 --initial-cluster etcd133=http://192.168.110.133:2380,etcd131=http://192.168.110.131:2380,etcd132=http://192.168.110.132:2380 --initial-advertise-peer-urls http://192.168.110.133:2380 --data-dir /var/lib/etcd/cluster.etcd 2022-01-11 16:44:08.375319 I | etcdserver/membership: added member 341a3c460c1c993a [http://192.168.110.131:2380] to cluster dd7594df5e81191b 2022-01-11 16:44:08.375393 I | etcdserver/membership: added member 4679fe0fcb37326d [http://192.168.110.132:2380] to cluster dd7594df5e81191b 2022-01-11 16:44:08.375404 I | etcdserver/membership: added member ab23bcc86cf3190b [http://192.168.110.133:2380] to cluster dd7594df5e81191b [root@etcd2 ~]# etcdctl snapshot restore student.data --name etcd131 --initial-cluster etcd133=http://192.168.110.133:2380,etcd131=http://192.168.110.131:2380,etcd132=http://192.168.110.132:2380 --initial-advertise-peer-urls http://192.168.110.131:2380 --data-dir /var/lib/etcd/cluster.etcd 2022-01-11 16:45:18.378931 I | etcdserver/membership: added member 341a3c460c1c993a [http://192.168.110.131:2380] to cluster dd7594df5e81191b 2022-01-11 16:45:18.378991 I | etcdserver/membership: added member 4679fe0fcb37326d [http://192.168.110.132:2380] to cluster dd7594df5e81191b 2022-01-11 16:45:18.379000 I | etcdserver/membership: added member ab23bcc86cf3190b [http://192.168.110.133:2380] to cluster dd7594df5e81191b [root@etcd3 ~]# etcdctl snapshot restore student.data --name etcd132 --initial-cluster etcd133=http://192.168.110.133:2380,etcd131=http://192.168.110.131:2380,etcd132=http://192.168.110.132:2380 --initial-advertise-peer-urls http://192.168.110.132:2380 --data-dir /var/lib/etcd/cluster.etcd 2022-01-11 16:46:26.826533 I | etcdserver/membership: added member 341a3c460c1c993a [http://192.168.110.131:2380] to cluster dd7594df5e81191b 2022-01-11 16:46:26.826584 I | etcdserver/membership: added member 4679fe0fcb37326d [http://192.168.110.132:2380] to cluster dd7594df5e81191b 2022-01-11 16:46:26.826595 I | etcdserver/membership: added member ab23bcc86cf3190b [http://192.168.110.133:2380] to cluster dd7594df5e81191b 修改所有节点数据目录的属主
[root@etcd1 ~]# chown -R etcd:etcd /var/lib/etcd/ [root@etcd2 ~]# chown -R etcd:etcd /var/lib/etcd/ [root@etcd3 ~]# chown -R etcd:etcd /var/lib/etcd/ 启动etcd
[root@etcd1 ~]# systemctl start etcd [root@etcd2 ~]# systemctl start etcd [root@etcd3 ~]# systemctl start etcd 可以发现数据已经恢复
[root@etcd1 ~]# etcdctl get student1 student1 59 [root@etcd3 ~]# etcdctl get student2 student2 62 八.Kubernetes(k8s)中以pod方式运行的etcd
etcd在Kubernetes集群中可以以pod的方式运行，也可以以物理机部署的方式运行，本章讲解以pod方式运行的etcd。
在此之前，需要有一套可以正常运行的Kubernetes集群，关于Kubernetes(k8s)集群的安装部署，可以查看博客《Centos7 安装部署Kubernetes(k8s)集群》https://www.cnblogs.com/renshengdezheli/p/16686769.html
在k8s中etcd以pod的方式运行，那配置文件在哪里，数据目录在哪里？
查看etcd pod，k8s中etcd为etcd-k8scloude1
[root@k8scloude1 ~]# kubectl get pods NAME READY STATUS RESTARTS AGE calico-kube-controllers-6b9fbfff44-4jzkj 1/1 Running 4 2d4h calico-node-bdlgm 1/1 Running 2 2d4h calico-node-hx8bk 1/1 Running 2 2d4h calico-node-nsbfs 1/1 Running 2 2d4h coredns-545d6fc579-7wm95 1/1 Running 2 2d4h coredns-545d6fc579-87q8j 1/1 Running 2 2d4h etcd-k8scloude1 1/1 Running 2 2d4h kube-apiserver-k8scloude1 1/1 Running 2 2d4h kube-controller-manager-k8scloude1 1/1 Running 2 2d4h kube-proxy-599xh 1/1 Running 2 2d4h kube-proxy-lpj8z 1/1 Running 2 2d4h kube-proxy-zxlk9 1/1 Running 2 2d4h kube-scheduler-k8scloude1 1/1 Running 2 2d4h metrics-server-bcfb98c76-k5dmj 1/1 Running 1 33h 在k8s中etcd以pod的形式运行， 此etcd的配置文件在哪？在/etc/kubernetes/manifests/etcd.yaml
[root@k8scloude1 ~]# ls /etc/kubernetes/manifests/etcd.yaml /etc/kubernetes/manifests/etcd.yaml [root@k8scloude1 ~]# cat !$ cat /etc/kubernetes/manifests/etcd.yaml apiVersion: v1 kind: Pod metadata: annotations: kubeadm.kubernetes.io/etcd.advertise-client-urls: https://192.168.110.130:2379 creationTimestamp: null labels: component: etcd tier: control-plane name: etcd namespace: kube-system spec: containers: - command: - etcd - --advertise-client-urls=https://192.168.110.130:2379 - --cert-file=/etc/kubernetes/pki/etcd/server.crt - --client-cert-auth=true - --data-dir=/var/lib/etcd - --initial-advertise-peer-urls=https://192.168.110.130:2380 - --initial-cluster=k8scloude1=https://192.168.110.130:2380 - --key-file=/etc/kubernetes/pki/etcd/server.key - --listen-client-urls=https://127.0.0.1:2379,https://192.168.110.130:2379 - --listen-metrics-urls=http://127.0.0.1:2381 - --listen-peer-urls=https://192.168.110.130:2380 - --name=k8scloude1 - --peer-cert-file=/etc/kubernetes/pki/etcd/peer.crt - --peer-client-cert-auth=true - --peer-key-file=/etc/kubernetes/pki/etcd/peer.key - --peer-trusted-ca-file=/etc/kubernetes/pki/etcd/ca.crt - --snapshot-count=10000 - --trusted-ca-file=/etc/kubernetes/pki/etcd/ca.crt image: registry.aliyuncs.com/google_containers/etcd:3.4.13-0 imagePullPolicy: IfNotPresent livenessProbe: failureThreshold: 8 httpGet: host: 127.0.0.1 path: /health port: 2381 scheme: HTTP initialDelaySeconds: 10 periodSeconds: 10 timeoutSeconds: 15 name: etcd resources: requests: cpu: 100m ephemeral-storage: 100Mi memory: 100Mi startupProbe: failureThreshold: 24 httpGet: host: 127.0.0.1 path: /health port: 2381 scheme: HTTP initialDelaySeconds: 10 periodSeconds: 10 timeoutSeconds: 15 volumeMounts: - mountPath: /var/lib/etcd name: etcd-data - mountPath: /etc/kubernetes/pki/etcd name: etcd-certs hostNetwork: true priorityClassName: system-node-critical volumes: - hostPath: path: /etc/kubernetes/pki/etcd type: DirectoryOrCreate name: etcd-certs - hostPath: path: /var/lib/etcd type: DirectoryOrCreate name: etcd-data status: {} 可以发现挂载了数据卷，数据目录在/var/lib/etcd/
[root@k8scloude1 ~]# ls /var/lib/etcd/ member [root@k8scloude1 ~]# ls /var/lib/etcd/member/ snap wal 
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