For those of you who didn’t know, Docker is an open-source tool that makes creating and managing Linux containers (LXC) easy. With Docker, the applications resides inside the container on top of the Linux operating system. Docker uses Kernel features such as cgroups and namespace to allow independent container to run on single os instance.
This article assumes you have at least basic knowledge of linux, know how to use the shell, and most importantly, you host your site on your own VPS. The installation is quite simple. I will show you through the step by step installation Docker on CentOS 7.
Step 1. First of all make sure that all packages are up to date.
yum -y update
Step 2. Install Docker using YUM.
Docker is included by default in the CentOS-Extras repository. To install run the following command:
yum -y install docker
yum -y install device-mapper device-mapper-event device-mapper-libs device-mapper-event-libs
Start and enable Docker service:
systemctl start docker.service
systemctl enable docker.service
And verify your work by checking the status of Docker:
systemctl status docker.service
Step 3. Download Docker Container.
Let’s begin using Docker, Download the centos Docker image:
docker pull centos
Verify CentOS images that have been fetched:
docker images centos
Step 4. Run a Docker Container.
As we can see centos container has been started and we got the bash shell. In docker command we have used options like ‘-i attaches stdin and stdout’ and ‘-t allocates a terminal or console’.
docker run -i -t centos /bin/bash
Step 5. Configure FirewallD.
FirwallD in CentOS 7 can conflict with Docker, it is recommended to disable the service. Run the following command:
systemctl stop firewalld.service
systemctl disable firewalld.service
Congratulation’s! You have successfully installed Docker. Thanks for using this tutorial for installing Docker on CentOS 7 system.