How to Install Docker on CentOS 7: A Complete Step-by-Step Guide

Background

After handling several projects that rely on Docker, the author notes that Docker has become essential in the cloud‑native era and shares a full installation guide for Linux.

Docker and System Versions

Docker is offered as Community Edition (CE) and Enterprise Edition (EE); the guide uses CE. It runs on 64‑bit CentOS 7/8 with a kernel version of at least 3.10.

Check the OS version with lsb_release -a or cat /etc/redhat-release. Example output shows CentOS 7. Verify the kernel with cat /proc/version, uname -a or uname -r; the sample shows a kernel of 3.10.x, which satisfies Docker’s requirement.

Automated Docker Installation

Docker provides a one‑click script, and the Chinese service DaoCloud offers an alternative.

curl -fsSL https://get.docker.com | bash -s docker --mirror Aliyun

curl -sSL https://get.daocloud.io/docker | sh

Running either command installs Docker automatically.

Manual Docker Installation

Uninstall old versions (optional)

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

Set up the repository

Install required utilities first:

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

Add the official Docker repo:

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

For faster access in China, replace the URL with mirrors such as Aliyun or Tsinghua:

Aliyun: https://mirrors.aliyun.com/docker-ce/linux/centos/docker-ce.repo

Tsinghua: https://mirrors.tuna.tsinghua.edu.cn/docker-ce/linux/centos/docker-ce.repo

Install Docker Engine

sudo yum install -y docker-ce docker-ce-cli containerd.io

If only the engine is needed, a minimal install works: yum install -y docker-ce After installation Docker is present but not started.

Start Docker

sudo systemctl start docker

Verify the installation by pulling and running the hello‑world image:

# docker pull hello-world
# docker run hello-world

A successful run prints a message confirming that Docker works correctly.

Reload daemon: systemctl daemon-reload Restart Docker: systemctl restart docker or service docker restart Stop Docker: systemctl stop docker or

docker service stop

Remove Docker

yum remove docker-ce

Delete all images, containers and configuration files:

rm -rf /var/lib/docker

Common Docker Commands

Search images: docker search IMAGE_NAME Pull image: docker pull IMAGE_NAME List running containers: docker ps List all containers: docker ps -a Remove container: docker rm CONTAINER_ID List images: docker images Remove image: docker rmi IMAGE_ID Start stopped container: docker start CONTAINER_ID Stop container: docker stop CONTAINER_ID Restart container: docker restart CONTAINER_ID Run a new container interactively: docker run -it ubuntu /bin/bash Enter a running container: docker exec -it CONTAINER_ID /bin/bash Additional options are available via docker help.