1、安裝環境
此處在Centos7進行安裝，可以使用以下命令查看CentOS版本
lsb_release -a
在 CentOS 7安裝docker要求系統為64位、系統內核版本為 3.10 以上，可以使用以下命令查看
uname -r
2、用yum源安裝
2.1 查看是否已安裝docker列表
yum list installed | grep docker
2.2 安裝docker
yum -y install docker
-y表示不詢問安裝，直到安裝成功，安裝完后再次查看安裝列表
2.3 啟動docker
systemctl start docker
2.4 查看docker服務狀態
systemctl status docker
以上說明docker安裝成功
3、離線安裝模式
3.1 安裝包官方地址：https://download.docker.com/linux/static/stable/x86_64/
可以先下載到本地，然后通過ftp工具上傳到服務器上，或者在服務器上使用命令下載
wget https://download.docker.com/linux/static/stable/x86_64/docker-18.06.3-ce.tgz
3.2 解壓
tar -zxvf docker-18.06.3-ce.tgz
3.3 將解壓出來的docker文件復制到 /usr/bin/ 目錄下
cp docker/* /usr/bin/
3.4 在/etc/systemd/system/目錄下新增docker.service文件，內容如下，這樣可以將docker注冊為service服務
[Unit] Description=Docker Application Container Engine Documentation=https://docs.docker.com After=network-online.target firewalld.service Wants=network-online.target [Service] Type=notify # the default is not to use systemd for cgroups because the delegate issues still # exists and systemd currently does not support the cgroup feature set required # for containers run by docker ExecStart=/usr/bin/dockerd --selinux-enabled=false --insecure-registry=127.0.0.1 ExecReload=/bin/kill -s HUP $MAINPID # Having non-zero Limit*s causes performance problems due to accounting overhead # in the kernel. We recommend using cgroups to do container-local accounting. LimitNOFILE=infinity LimitNPROC=infinity LimitCORE=infinity # Uncomment TasksMax if your systemd version supports it. # Only systemd 226 and above support this version. #TasksMax=infinity TimeoutStartSec=0 # set delegate yes so that systemd does not reset the cgroups of docker containers Delegate=yes # kill only the docker process, not all processes in the cgroup KillMode=process # restart the docker process if it exits prematurely Restart=on-failure StartLimitBurst=3 StartLimitInterval=60s [Install] WantedBy=multi-user.target
此處的--insecure-registry=127.0.0.1（此處改成你私服ip）設置是針對有搭建了自己私服Harbor時允許docker進行不安全的訪問，否則訪問將會被拒絕。
3.5 啟動docker
給docker.service文件添加執行權限
chmod +x /etc/systemd/system/docker.service
重新加載配置文件（每次有修改docker.service文件時都要重新加載下）
systemctl daemon-reload
啟動
systemctl start docker
設置開機啟動
systemctl enable docker.service
查看docker服務狀態
systemctl status docker
上圖表示docker已安裝成功