一. 准备工作

1. 准备三台虚拟机,我这里用的是 vagrant + virtualbox
2. 配置三台虚拟机ip为

node1 = 192.168.33.11
node2 = 192.168.33.12
node3 = 192.168.33.13

二. 安装docker

PS. 参考地址为:https://docs.docker.com/install/linux/docker-ce/centos/#install-docker-ce

sudo yum install -y yum-utils \
             device-mapper-persistent-data \
             lvm2

sudo yum-config-manager \
            --add-repo \
          https://download.docker.com/linux/centos/docker-ce.repo

sudo yum-config-manager --disable docker-ce-edge

sudo yum install docker-ce -y

sudo systemctl start docker

三. 创建集群容器

PS. etcd cluster有三种启动集群的机制这里使用第二种etcd Discovery

1. discovery URL有二种创建方法,分别是Custom etcd Discovery Service和Public etcd Discovery Service,因为我们是首次搭建集群,无现成的etcd集群,所以无法使用第一种,因此使用第二种Public etcd Discovery Service

 curl https://discovery.etcd.io/new?size=3
#返回 https://discovery.etcd.io/e8a57bd1131c6b466d32989e81e441e3

2. 根据上面命令返回的Discovery URL编写创建容器脚本
   node1:

# For each machine
ETCD_VERSION=v3.0.0
TOKEN=etcd-token
CLUSTER_STATE=new
DISCOVERY=https://discovery.etcd.io/e8a57bd1131c6b466d32989e81e441e3

# For node 1
THIS_NAME=etcd-node-1
THIS_IP=192.168.33.11
sudo docker run -d --net=host  --name etcd quay.io/coreos/etcd:${ETCD_VERSION} \
    /usr/local/bin/etcd \
    --name ${THIS_NAME} \
    --initial-advertise-peer-urls http://${THIS_IP}:2380 \
    --listen-peer-urls http://${THIS_IP}:2380 \
    --advertise-client-urls http://${THIS_IP}:2379 \
    --listen-client-urls http://${THIS_IP}:2379,http://127.0.0.1:2379 \
    --initial-cluster-state ${CLUSTER_STATE} \
    --initial-cluster-token ${TOKEN} \
    --discovery ${DISCOVERY}

node2:

# For each machine
ETCD_VERSION=v3.0.0
TOKEN=etcd-token
CLUSTER_STATE=new
DISCOVERY=https://discovery.etcd.io/e8a57bd1131c6b466d32989e81e441e3

# For node 2
THIS_NAME=etcd-node-2
THIS_IP=192.168.33.12
sudo docker run -d --net=host  --name etcd quay.io/coreos/etcd:${ETCD_VERSION} \
    /usr/local/bin/etcd \
    --name ${THIS_NAME} \
    --initial-advertise-peer-urls http://${THIS_IP}:2380 \
    --listen-peer-urls http://${THIS_IP}:2380 \
    --advertise-client-urls http://${THIS_IP}:2379 \
    --listen-client-urls http://${THIS_IP}:2379,http://127.0.0.1:2379 \
    --initial-cluster-state ${CLUSTER_STATE} \
    --initial-cluster-token ${TOKEN} \
    --discovery ${DISCOVERY}

node3:

# For each machine
ETCD_VERSION=v3.0.0
TOKEN=etcd-token
CLUSTER_STATE=new
DISCOVERY=https://discovery.etcd.io/e8a57bd1131c6b466d32989e81e441e3

# For node 3
THIS_NAME=etcd-node-3
THIS_IP=192.168.33.13
sudo docker run -d --net=host  --name etcd quay.io/coreos/etcd:${ETCD_VERSION} \
    /usr/local/bin/etcd \
    --name ${THIS_NAME} \
    --initial-advertise-peer-urls http://${THIS_IP}:2380 \
    --listen-peer-urls http://${THIS_IP}:2380 \
    --advertise-client-urls http://${THIS_IP}:2379 \
    --listen-client-urls http://${THIS_IP}:2379,http://127.0.0.1:2379 \
    --initial-cluster-state ${CLUSTER_STATE} \
    --initial-cluster-token ${TOKEN} \
    --discovery ${DISCOVERY}

3. 创建容器的注意事项:
   因为该容器是基于alpine的系统镜像,不包含ca证书,因为Discovery URL为https,所以需要下载

sudo docker exec -it etcd sh
apk update 
apk  add ca-certificates
#然后重启容器
docker restart  etcd

4. 关于集群的问题节点node3删除和新增节点node4代替node3
   ①. 新增节点,得到新增节点信息

#新增节点
etcdctl member add etcd-node-4 http://192.168.33.14
#返回的新增节点信息
#Added member named etcd-node-5 with ID b6cf922403228631 to cluster
#ETCD_NAME="etcd-node-5"
#ETCD_INITIAL_CLUSTER="etcd-node-2=http://192.168.33.12:2380,etcd-#node-5=http://192.168.33.15:2380,=http://192.168.33.13:2380,etcd-node-#4=http://192.168.33.14:2380,etcd-node-1=http://192.168.33.11:2380"
#ETCD_INITIAL_CLUSTER_STATE="existing"

②. 新增一台虚拟主机,ip分配为:192.168.33.14,并安装docker
③. 根据返回的新增节点信息,编写新增节点容器脚本

# For each machine
ETCD_VERSION=v3.0.0
TOKEN=etcd-token
CLUSTER_STATE=existing
NAME_1=etcd-node-1
NAME_2=etcd-node-2
NAME_3=etcd-node-3
NAME_4=etcd-node-4
HOST_1=192.168.33.11
HOST_2=192.168.33.12
HOST_3=192.168.33.13
HOST_4=192.168.33.14
CLUSTER=${NAME_1}=http://${HOST_1}:2380,${NAME_2}=http://${HOST_2}:2380,${NAME_3}=http://${HOST_3}:2380,${NAME_4}=http://${HOST_4}:2380
# For node 1
sudo docker run -d  --net=host --name etcd quay.io/coreos/etcd:${ETCD_VERSION} \
    /usr/local/bin/etcd \
    --name ${NAME_4} \
    --initial-advertise-peer-urls http://${HOST_4}:2380 --listen-peer-urls http://${HOST_4}:2380 \
    --advertise-client-urls http://${HOST_4}:2379 --listen-client-urls http://${HOST_4}:2379,http://127.0.0.1:2379 \
    --initial-cluster ${CLUSTER} \
    --initial-cluster-state ${CLUSTER_STATE} --initial-cluster-token ${TOKEN}

④:删除问题节点node3

etcdctl member remove 问题节点ID