【linux下centos7.9安装docker，docker-composed（root用户）】

一 安装docker

1.联网下载安装docker
curl -fsSL https://get.docker.com | bash -s docker --mirror Aliyun
2.安装成功
docker -v
3.将docker注册为service，进入/etc/systemd/system/目录,并创建docker.service文件（注意insecure-registry修改成自己的地址）
cd /etc/systemd/system/
touch docker.service
输入内容

[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

4.给docker.service文件添加执行权限
chmod +x /etc/systemd/system/docker.service
5.重新加载配置文件（每次有修改docker.service文件时都要重新加载下）
systemctl daemon-reload
6.启动docker
systemctl start docker
7.设置开机启动
systemctl enable docker.service
8.查看docker启动状态
systemctl status docker

二 安装docker-composed

1.安装docker-composed，并放到/usr/local/bin/下面，

curl -L “https://github.com/docker/compose/releases/download/v2.18.1/docker-compose-$(uname-s)-$(uname -m)” -o /usr/local/bin/docker-compose
2.并赋予权限
sudo chmod +x /usr/local/bin/docker-compose
3.检查版本
docker-compose -v