How to install Docker on CentOS 7 machine

Overview:

1. CentOS machine based on 7.9.2009(Core) release
2. To check the version of the CentOS machine use:

   cat /etc/centos-release
   

3. Docker community edition is installed

Docker installation and configuration:

1. Remove the old version of the Docker from the machine:

   sudo yum remove -y docker \
   docker-client \
   docker-client-latest \
   docker-common \
   docker-latest \
   docker-latest-logrotate \
   docker-logrotate \
   docker-engine
   

2. Install prerequisite utility software:

   sudo yum install -y yum-utils \
   device-mapper-persistent-data \
   lvm2
   

3. Install the Docker repository:

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

4. Install the Docker:

   sudo yum install -y docker-ce
   

5. Start Docker daemon and enable autostartup:

   sudo systemctl start docker && sudo systemctl enable docker
   

6. Add your current user to the docker group:

   sudo usermod -aG docker [username]
   

7. For changes to take effect logout from your instance and then log back in
8. Check the installed Docker version:

   docker version
   

Reference:

1. yum-utils is a collection of tools and programs for managing yum repositories, installing debug packages, source packages, extended information from repositories and administration.
2. device-mapper-persistent-data
3. LVM2 refers to the userspace toolset that provide logical volume management facilities on linux. It is reasonably backwards-compatible with the original LVM toolset.