Etcd是用Go编写的简单，可靠，快速和安全的开源键值存储。它使用Raft共识算法来管理高可用性的复制日志。在本教程中，我们将在Ubuntu 18.04/Ubuntu 16.04上安装单个节点(一个成员)etcd。

在Ubuntu 18.04/Ubuntu 16.04上安装etcd

尽管我们可以从源代码构建Etcd，但它作为二进制包分发。在本教程中，将下载预构建的二进制程序包。

在继续获取最新的发行标签之前，请检查预构建的发行二进制文件。

在Ubuntu 18.04/Ubuntu 16.04上下载最新版本的etcd：

sudo apt -y install wget
export RELEASE="3.3.13"
wget https://github.com/etcd-io/etcd/releases/download/v${RELEASE}/etcd-v${RELEASE}-linux-amd64.tar.gz

解压缩下载的存档文件。

tar xvf etcd-v${RELEASE}-linux-amd64.tar.gz

切换到新文件目录

cd etcd-v${RELEASE}-linux-amd64

将etcd和etcdctl二进制文件移至/usr/local/bin目录。

sudo mv etcd etcdctl /usr/local/bin

确认版本。

$etcd --version
 etcd Version: 3.3.13
 Git SHA: 98d3084
 Go Version: go1.10.8
 Go OS/Arch: linux/amd64

创建Etcd配置文件和数据目录。

sudo mkdir -p /var/lib/etcd/
sudo mkdir /etc/etcd

创建etcd系统用户

sudo groupadd --system etcd
sudo useradd -s /sbin/nologin --system -g etcd etcd

将/var/lib/etcd /目录所有权设置为etcd用户。

sudo chown -R etcd:etcd /var/lib/etcd/

配置Systemd并启动etcd服务

为etcd创建一个新的systemd服务文件。

sudo vim /etc/systemd/system/etcd.service

将以下数据粘贴到文件中。

[Unit]
Description=etcd key-value store
Documentation=https://github.com/etcd-io/etcd
After=network.target

[Service]
User=etcd
Type=notify
Environment=ETCD_DATA_DIR=/var/lib/etcd
Environment=ETCD_NAME=%m
ExecStart=/usr/local/bin/etcd
Restart=always
RestartSec=10s
LimitNOFILE=40000

[Install]
WantedBy=multi-user.target

在Ubuntu 18,04/Ubuntu 16,04上重新加载systemd服务并启动etcd

sudo systemctl  daemon-reload
sudo systemctl  start etcd.service

检查服务状态：

$sudo systemctl  status etcd.service
 ● etcd.service - etcd key-value store
    Loaded: loaded (/etc/systemd/system/etcd.service; disabled; vendor preset: enabled)
    Active: active (running) since Sat 2019-01-05 00:54:20 EAT; 23s ago
      Docs: https://github.com/etcd-io/etcd
  Main PID: 8792 (etcd)
     Tasks: 13 (limit: 4915)
    CGroup: /system.slice/etcd.service
            └─8792 /usr/local/bin/etcd
 Ama 05 00:54:20 mynix etcd[8792]: 8e9e05c52164694d received MsgVoteResp from 8e9e05c52164694d at term 2
 Ama 05 00:54:20 mynix etcd[8792]: 8e9e05c52164694d became leader at term 2
 Ama 05 00:54:20 mynix etcd[8792]: raft.node: 8e9e05c52164694d elected leader 8e9e05c52164694d at term 2
 Ama 05 00:54:20 mynix etcd[8792]: setting up the initial cluster version to 3.3
 Ama 05 00:54:20 mynix etcd[8792]: set the initial cluster version to 3.3
 Ama 05 00:54:20 mynix etcd[8792]: enabled capabilities for version 3.3
 Ama 05 00:54:20 mynix etcd[8792]: ready to serve client requests
 Ama 05 00:54:20 mynix etcd[8792]: published {Name:5fbf3d068d6c491eb687a7a427fc2263 ClientURLs:[http://localhost:2379]} to cluster cdf818194e3a8c32
 Ama 05 00:54:20 mynix systemd[1]: Started etcd key-value store.
 Ama 05 00:54:20 mynix etcd[8792]: serving insecure client requests on 127.0.0.1:2379, this is strongly discouraged!

该服务将在本地主机地址端口" 2379"上启动

$ss -tunelp | grep 2379
 tcp   LISTEN 0 128 127.0.0.1:2379 0.0.0.0:*  uid:998 ino:72981 sk:45c <-> 

$etcdctl member list
 8e9e05c52164694d: name=5fbf3d068d6c491eb687a7a427fc2263 peerURLs=http://localhost:2380 clientURLs=http://localhost:2379 isLeader=true