centos7靜態二進制文件離線安裝
官方參考：https://docs.docker.com/install/linux/docker-ce/binaries/#install-static-binaries
官方安裝參考真的踩過很多坑。。。
1. 下載靜態二進制文件
docker下載地址：https://download.docker.com，根據需要下載相應的docker文件。
x86服務器64位linux穩定版靜態二進制文件下載地址：https://download.docker.com/linux/static/stable/x86_64，下載需要版本的.tgz。
2. 安裝
docker是先要用root用戶進行安裝的
$ tar xzvf /path/to/<FILE>.tar.gz
$ chmod 755 -R docker/
$ cp docker/* /usr/bin/
3. 把docker註冊成服務
$ vi /etc/systemd/system/docker.service
編輯服務配置文件
[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
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
開啓docker服務
$ systemctl enable docker
$ systemctl start docker
4. 驗證
通過查看docker的版本命令，驗證docker 是否啓動成功
$ docker version
5.配置非root用戶操作docker
前提要在docker啓動的情況下，創建docker用戶，設置密碼
$ useradd docker
$ passwd docker
# 理論上創建了docker用戶，會默認在docker組，但是爲了防止萬一，手動再創建docker組
$ groupadd docker
$ gpasswd -a docker docker
# 重啓docker
$ systemctl restart docker
# 驗證
$ docker version