Currently, docker is very popular. Of course, compared with k8s, docker is slightly less powerful, but it is still widely used and convenient. Here are two ways to install docker

First type: yum source installation

This method is relatively simple to install, but first make sure that yum is installed on the server (usually comes with it).

First, check whether there is a docker

yum list installed | grep docker

Install directly if it doesn't exist

yum -y install docker

Start docker

systemctl start docker
#Stop is stop

View docker status

systemctl status docker

 

You can see the activation status, indicating that the installation is successful

The second way is to install offline:

Official installation package address: https://download.docker.com/linux/static/stable/x86_64/

wget https://download.docker.com/linux/static/stable/x86_64/docker-18.06.3-ce.tgz

decompression

tar -zxvf docker-18.06.3-ce.tgz

Copy the extracted docker file to the directory / usr/bin /

cp docker/* /usr/bin/

Add the docker.service file in the directory / etc/systemd/system /. The content is as follows. In this way, you can register the docker as a service

[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

The setting of -- secure registry = 127.0.0.1 (changed to your private ip here) here is to allow the docker to have insecure access when you have set up your own private Harbor, otherwise the access will be denied

Start docker

Add execution permission to docker.service file

chmod +x /etc/systemd/system/docker.service 

Reload the configuration file (reload every time you modify the docker.service file)

systemctl daemon-reload    

start-up

systemctl start docker

Set startup

systemctl enable docker.service

View docker service status

systemctl status docker

The above figure shows that docker has been installed successfully

It may be said that for the simple installation of Yum source, you need to see the offline installation. In fact, I want to say that it's only for standby. In case of any problem with the yum installation, you can try the offline installation. No matter what kind of installation is successful, it's ok!