安装etcd

etcd的安装还是比较简单的

yum install wget –y
wget https://github.com/etcd-io/etcd/releases/download/v3.4.13/etcd-v3.4.13-linux-amd64.tar.gz
tar -xvf etcd-v3.4.13-linux-amd64.tar.gz
rm -rf etcd-v3.4.13-linux-amd64.tar.gz && cd etcd-v3.4.13-linux-amd64

单机启动就直接在etcd根目录下./etcd就行了

创建三节点集群

容器启动

因为没有多台物理机，直接用多个容器，不同端口太替代吧

# 以centos7为基础镜像，内部暴露2379和2380端口，2379端口提供增删改查，2380端口节点间通信
docker run –name etcd1 –p 2379:2379 –p 2380:2380 –it centos:7 /bin/bash
docker run –name etcd1 –p 2479:2379 –p 2480:2380 –it centos:7 /bin/bash
docker run –name etcd1 –p 2579:2379 –p 2580:2380 –it centos:7 /bin/bash

启动etcd1

# initial-cluster-state必须为new，initial-cluster必须包含新建集群的所有节点
# etcd1启动时会提示etcd2和etcd3连接超时，后面这些节点启动起来就不显示了
# initial-advertise-peer-urls和initial-cluster要写宿主机ip，其他都是0.0.0.0
./etcd -name etcd1 \
  -advertise-client-urls http://0.0.0.0:2379 \
  -listen-client-urls http://0.0.0.0:2379 \
  -listen-peer-urls http://0.0.0.0:2380 \
  -initial-advertise-peer-urls http://159.75.26.246:2380 \
  -initial-cluster-token etcd-cluster \
  -initial-cluster "etcd1=http://159.75.26.246:2380,etcd2=http://159.75.26.246:2480,etcd3=http://159.75.26.246:2580" \
  -initial-cluster-state new

启动etcd2

./etcd -name etcd2 \
  -advertise-client-urls http://0.0.0.0:2379 \
  -listen-client-urls http://0.0.0.0:2379 \
  -listen-peer-urls http://0.0.0.0:2380 \
  -initial-advertise-peer-urls http://159.75.26.246:2480 \
  -initial-cluster-token etcd-cluster \
  -initial-cluster "etcd1=http://159.75.26.246:2380,etcd2=http://159.75.26.246:2480,etcd3=http://159.75.26.246:2580" \
  -initial-cluster-state new

启动etcd3

./etcd -name etcd3 \
  -advertise-client-urls http://0.0.0.0:2379 \
  -listen-client-urls http://0.0.0.0:2379 \
  -listen-peer-urls http://0.0.0.0:2380 \
  -initial-advertise-peer-urls http://159.75.26.246:2580 \
  -initial-cluster-token etcd-cluster \
  -initial-cluster "etcd1=http://159.75.26.246:2380,etcd2=http://159.75.26.246:2480,etcd3=http://159.75.26.246:2580" \
  -initial-cluster-state new

查看集群状态

# 要制定集群内所有节点
./etcdctl --endpoints=159.75.26.246:2380,159.75.26.246:2480,159.75.26.246:2580, member list

2节点集群添加新的2个节点

首先说明下，2节点一般不能组成集群，至少要3个节点。但是新建集群可以任意节点数，但是集群如果有节点掉线，存活节点数少于3个则集群会失效。

etcd1和etcd2是原节点，我们新增加的节点是etcd3和etcd4，这四个节点的容器启动和上述差不多。四个节点端口映射如下：

etcd端口	2379	2380
etcd1映射至宿主机端口	2379	2380
etcd2映射至宿主机端口	2479	2480
etcd3映射至宿主机端口	2579	2580
etcd4映射至宿主机端口	2679	2680

启动原节点

# 启动etcd1（注意initial-cluster就两个节点，新建集群就两个节点
./etcd -name etcd1 \
  -advertise-client-urls http://0.0.0.0:2379 \
  -listen-client-urls http://0.0.0.0:2379 \
  -listen-peer-urls http://0.0.0.0:2380 \
  -initial-advertise-peer-urls http://159.75.26.246:2380 \
  -initial-cluster-token etcd-cluster \
  -initial-cluster "etcd1=http://159.75.26.246:2380,etcd2=http://159.75.26.246:2480" \
  -initial-cluster-state new
# 动etcd2
./etcd -name etcd2 \
  -advertise-client-urls http://0.0.0.0:2379 \
  -listen-client-urls http://0.0.0.0:2379 \
  -listen-peer-urls http://0.0.0.0:2380 \
  -initial-advertise-peer-urls http://159.75.26.246:2480 \
  -initial-cluster-token etcd-cluster \
  -initial-cluster "etcd1=http://159.75.26.246:2380,etcd2=http://159.75.26.246:2480" \
  -initial-cluster-state new

增加新节点

首先要在任意原节点下，添加新增节点的基本信息，我们这里选择在etcd2下进行，也就是endpoints参数。etcd2会告诉整个集群将要加入的新节点的基本信息。

# 只能一个一个添加，这边add member后，对应新节点启动完（下面的命令），才能继续add下一新节点
./etcdctl --endpoints=159.75.26.246:2480 member add etcd3 http://159.75.26.246:2580
./etcdctl --endpoints=159.75.26.246:2480 member add etcd4 http://159.75.26.246:2680

我们进入etcd3新节点的容器，执行命令（initial-cluster是三个节点），并且initial-cluster-state是existing

./etcd -name etcd3 \
  -advertise-client-urls http://0.0.0.0:2379 \
  -listen-client-urls http://0.0.0.0:2379 \
  -listen-peer-urls http://0.0.0.0:2380 \
  -initial-advertise-peer-urls http://159.75.26.246:2580 \
  -initial-cluster-token etcd-cluster \
  -initial-cluster "etcd1=http://159.75.26.246:2380,etcd2=http://159.75.26.246:2480,etcd3=http://159.75.26.246:2580" \
  -initial-cluster-state existing

再进入etcd4容器执行命令行，etcd3已经加进去了，所以initial-cluster是四个节点

./etcd -name etcd4 \
  -advertise-client-urls http://0.0.0.0:2379 \
  -listen-client-urls http://0.0.0.0:2379 \
  -listen-peer-urls http://0.0.0.0:2380 \
  -initial-advertise-peer-urls http://159.75.26.246:2680 \
  -initial-cluster-token etcd-cluster \
  -initial-cluster "etcd1=http://159.75.26.246:2380,etcd2=http://159.75.26.246:2480,etcd3=http://159.75.26.246:2580,etcd4=http://159.75.26.246:2680" \
  -initial-cluster-state existing

至此2+2集群搭建完毕

目录CONTENT

etcd集群搭建