yum安装etcd集群

　   前一篇文章介绍了如何yum安装简单的kubernetes集群，其中etcd是单点部署。本篇我们来搭建etcd集群，方便日后搭建kubernetes HA集群架构。

1，环境配置说明

　　etcd1　　192.168.20.71

　　etcd2　　192.168.20.72

　　etcd3　　192.168.20.73

2，etcd版本

[root@master1 ~]# etcdctl --version
etcdctl version: 3.2.22
API version: 2

3，开始安装

　　etcd每台安装步骤都一样，所以etcd2、etcd3都以etcd1步骤一样

　　安装只需一条命令即可：

　　yum -y install etcd

4，查看并修改etcd配置文件

 #修配etcd配置文件
 [root@master1 ~]# ls /etc/etcd/
 etcd.conf  etcd.conf.back
 [root@master1 ~]# grep -v '^#' /etc/etcd/etcd.conf
 ETCD_NAME=etcd1

 ETCD_DATA_DIR="/var/lib/etcd/etcd1"

 ETCD_LISTEN_PEER_URLS="http://192.168.20.71:2380"

 ETCD_LISTEN_CLIENT_URLS="http://127.0.0.1:2379,http://192.168.20.71:2379"

 ETCD_INITIAL_ADVERTISE_PEER_URLS="http://192.168.20.71:2380"

 ETCD_INITIAL_CLUSTER="etcd1=http://192.168.20.71:2380,etcd2=http://192.168.20.72:2380,etcd3=http://192.168.20.73:2380"

 ETCD_INITIAL_CLUSTER_STATE="new"

 ETCD_INITIAL_CLUSTER_TOKEN="etcd-test"

 ETCD_ADVERTISE_CLIENT_URLS="http://192.168.20.71:2379"

5，启动etcd服务

 #etcd启动配置文件为：
 [root@master1 ~]# cat /usr/lib/systemd/system/etcd.service
 [Unit]
 Description=Etcd Server
 After=network.target
 After=network-online.target
 Wants=network-online.target

 [Service]
 Type=notify
 WorkingDirectory=/var/lib/etcd/
 EnvironmentFile=-/etc/etcd/etcd.conf
 User=etcd
 # set GOMAXPROCS to number of processors
 ExecStart=/bin/bash -c "GOMAXPROCS=$(nproc) /usr/bin/etcd --name=\"${ETCD_NAME}\" --data-dir=\"${ETCD_DATA_DIR}\" \
                     --listen-peer-urls=\"${ETCD_LISTEN_PEER_URLS}\" \
                     --listen-client-urls=\"${ETCD_LISTEN_CLIENT_URLS}\" \
                     --advertise-client-urls=\"${ETCD_ADVERTISE_CLIENT_URLS}\" \
                     --initial-cluster-token=\"${ETCD_INITIAL_CLUSTER_TOKEN}\" \
                     --initial-cluster=\"${ETCD_INITIAL_CLUSTER}\" \
                     --initial-cluster-state=\"${ETCD_INITIAL_CLUSTER_STATE}\""
 Restart=on-failure
 LimitNOFILE=

 [Install]
 WantedBy=multi-user.target

 #启动etcd服务
 systemctl start etcd
 #查看启动状态
 systemctl status etcd

6，etcd2、etcd3配置文件

 #etcd2配置文件
 [root@master2 ~]# cat /etc/etcd/etcd.conf
 ETCD_NAME=etcd2

 ETCD_DATA_DIR="/var/lib/etcd/etcd2"

 ETCD_LISTEN_PEER_URLS="http://192.168.20.72:2380"

 ETCD_LISTEN_CLIENT_URLS="http://127.0.0.1:2379,http://192.168.20.72:2379"

 ETCD_INITIAL_ADVERTISE_PEER_URLS="http://192.168.20.72:2380"

 ETCD_INITIAL_CLUSTER="etcd1=http://192.168.20.71:2380,etcd2=http://192.168.20.72:2380,etcd3=http://192.168.20.73:2380"

 ETCD_INITIAL_CLUSTER_STATE="new"

 ETCD_INITIAL_CLUSTER_TOKEN="etcd-test"

 ETCD_ADVERTISE_CLIENT_URLS="http://192.168.20.72:2379"

 #etcd3 配置文件
 [root@master ~]# cat /etc/etcd/etcd.conf
 ETCD_NAME=etcd3

 ETCD_DATA_DIR="/var/lib/etcd/etcd3"

 ETCD_LISTEN_PEER_URLS="http://192.168.20.73:2380"

 ETCD_LISTEN_CLIENT_URLS="http://127.0.0.1:2379,http://192.168.20.73:2379"

 ETCD_INITIAL_ADVERTISE_PEER_URLS="http://192.168.20.73:2380"

 ETCD_INITIAL_CLUSTER="etcd1=http://192.168.20.71:2380,etcd2=http://192.168.20.72:2380,etcd3=http://192.168.20.73:2380"

 ETCD_INITIAL_CLUSTER_STATE="new"

 ETCD_INITIAL_CLUSTER_TOKEN="etcd-test"

 ETCD_ADVERTISE_CLIENT_URLS="http://192.168.20.73:2379"

 #分别启动etcd2、etcd3服务
 #查看cluster状态
 [root@master1 ~]# etcdctl cluster-health
 member 85b5f1a0537e385d is healthy: got healthy result from http://192.168.20.71:2379
 member 9f304c9e0feb949d is healthy: got healthy result from http://192.168.20.72:2379
 member ec71f609370df393 is healthy: got healthy result from http://192.168.20.73:2379
 cluster is healthy

 #列出etcd服务状态
 [root@master1 ~]# etcdctl member list
 85b5f1a0537e385d: name=etcd1 peerURLs=http://192.168.20.71:2380 clientURLs=http://192.168.20.71:2379 isLeader=false
 9f304c9e0feb949d: name=etcd2 peerURLs=http://192.168.20.72:2380 clientURLs=http://192.168.20.72:2379 isLeader=false
 ec71f609370df393: name=etcd3 peerURLs=http://192.168.20.73:2380 clientURLs=http://192.168.20.73:2379 isLeader=true

 #从列出信息可以看出，目前是etcd3为主节点。
 #查看etcd服务启动日志，可通过 tail -f /var/log/message 动态查看

7，至此，etcd集群已配置完成。接下来可以对kubernetes集群apiserver配置文件进行修改，使其指向etcd集群

 #修改master节点，apiserver配置文件
 [root@master ~]# cat /etc/kubernetes/apiserver
 ###
 ## kubernetes system config
 KUBE_API_ADDRESS="--address=0.0.0.0"
 KUBE_API_PORT="--port=8080"
 KUBELET_PORT="--kubelet-port=10250"
 KUBE_ETCD_SERVERS="--etcd-servers=http://192.168.20.71:2379,http://192.168.20.72:2379,http://192.168.20.73:2379"
 KUBE_SERVICE_ADDRESSES="--service-cluster-ip-range=10.254.0.0/16"
 KUBE_API_ARGS="--service_account_key_file=/etc/kubernetes/serviceaccount.key"
 KUBE_ADMISSION_CONTROL="--admission-control=NamespaceLifecycle,NamespaceExists,LimitRanger,SecurityContextDeny,ServiceAccount,ResourceQuota"
 KUBE_API_ARGS=""

 #k8s集群做任何调整后，都需要重启服务
 #重启master各组件，可连起来写
 systemctl restart kube-apiserver kube-controller-manager kube-scheduler
 #重启node1、node2各组件
 systemctl restart kubelet kube-proxy

 #再次在master节点查看etcd、node集群状态
 #测试，可关闭一台etcd服务，创建一个pod，无异常
 #通过测试可以得出，etcd集群至少需要2个etcd节点才可以正常工作。

8，如何创建pod，参加下一篇文章。