How to install Docker in Centos 7

Date Posted : 20/12/2018

How to install Docker in Centos 7

Docker is a most handy DevOps tool used nowadays. In this post, we will explain Docker-CE installation and uninstallation steps.

Prerequisites

OS requirements

To install Docker CE, you need to maintained version of CentOS 7. Therefore, archived versions aren’t supported or tested.

Uninstall old versions

Older versions of Docker were called docker or docker-engine. If these are installed, uninstall them, along with associated dependencies.

# yum remove docker \
                  docker-client \
                  docker-client-latest \
                  docker-common \
                  docker-latest \
                  docker-latest-logrotate \
                  docker-logrotate \
                  docker-selinux \
                  docker-engine-selinux \
                  docker-engine

It’s OK if yum reports that none of these packages are installed.

The contents of /var/lib/docker/, including images, containers, volumes, and networks, are preserved. The Docker CE package is now called docker-ce.

Install Docker CE

Step by step procedure, to install your Docker CE on your VM

STEP 1: SET UP THE REPOSITORY

Install required packages. yum-utils provides the yum-config-manager utility,

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

Use the following command to set up the stable repository. You always need the stable repository,

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

STEP 2: Install the latest version of Docker CE .

# yum install docker-ce

If prompted to accept the GPG key, verify that the fingerprint matches060A 61C5 1B55 8A7F 742B 77AA C52F EB6B 621E 9F35, and if so, accept it.

STEP 3:

If you have multiple Docker repositories enabled, installing or updating without specifying a version in the yum install or yum update command always installs the highest possible version, which may not be appropriate for your stability needs.

STEP 4 : To install a specific version of Docker CE,

# yum list docker-ce --showduplicates | sort -r

docker-ce.x86_64     18.09.0.ce-1.el7.centos        docker-ce-stable

STEP 5 : start docker

# systemctl start docker

STEP 6 : Verify docker

Verify that docker is installed correctly by running the hello-world image.

# docker run hello-world

STEP 7 : Enable docker

By enabling docker , it will run ,even after the reboot of VM.

# systemctl Enable docker

Docker Installation is completed successfully.

Uninstall Docker CE

Uninstall the Docker package:

# yum remove docker-ce

 To delete all images, containers, and volumes:
Note : You must delete any edited configuration files manually.

# sudo rm -rf /var/lib/docker

We hope that you have understand the setup. It is pretty easy and if you have any query/concerns ,please comment below, we will answer your queries.