Install Docker
================

Check system info
----------------

First of all, get familiar with our computer system before the next steps. Noted that the commands below run in Linux.  

.. code-block:: bash

    lsb_release -a
    #LSB Version:    core-4.1-amd64:core-4.1-noarch
    #Distributor ID: CentOS
    #Description:    CentOS Linux release 7.9.2009 (Core)
    #Release:        7.9.2009
    #Codename:       Core



Install docker
--------------

Use **yum** to install packages in CentOS.

.. code-block:: bash

    # 1 Make your packages updated, if needed.
    sudo yum makecache fast 

    # 2 Install docker dependences
    sudo yum install -y yum-utils device-mapper-persistent-data lvm2

    # 3 Add docker repo
    sudo yum-config-manager --add-repo https://download.docker.com/linux/centos/docker-ce.repo

    # 4 Install docker
    sudo yum install -y docker-ce docker-ce-cli containerd.io

    # 5 Start docker
    sudo systemctl start docker

    # 6 Set Docker to boot automatically
    sudo systemctl enable docker
    # Created symlink from /etc/systemd/system/multi-user.target.wants/docker.service to /usr/lib/systemd/system/docker.service.

    # 7 Check docker
    sudo docker --version
    # Docker version 24.0.6, build ed223bc

    # 8 Check more docker info
    docker info

    # 9 We can reset the Docker Root Dir (/var/lib/docker, for default)

    sudo systemctl stop docker # stop docker

    sudo mkdir -p your_loc/docker/storage # create docker dir

    cat /etc/docker/daemon.json # check the docker configuration

    # if not exsit /etc/docker/daemon.json
    # create a json file using vi/vim or nona
    #{
    #    "data-root": "/datadisk/docker/storage"
    #}

    sudo systemctl start docker # reopen docker
    docker info # check docker configuration