Docker has become a standard tool for developing and deploying applications due to its ability to package applications into containers. Containers allow developers to bundle an application with all necessary dependencies into a standardized unit of software, making deployment and execution on any Linux system easier. This article will guide you through the steps of installing and setting up Docker on the CentOS 7 operating system.
Prerequisites
Before installing Docker, make sure your system meets the following requirements:
- Clean installation of CentOS 7
- Access to the root account or an account with sudo privileges
Step 1: Update System
First, update your system to ensure that all existing packages are upgraded to the latest versions. Open a terminal and run the following command:
sudo yum update -y
Step 2: Install Necessary Packages
Before installing Docker, you need to install several necessary packages that allow yum to use packages over HTTPS. Run the following command:
sudo yum install -y yum-utils device-mapper-persistent-data lvm2
Step 3: Add Docker Repository
Docker is not available in the default CentOS 7 repositories, so you need to add the official Docker repository. This will allow yum to find and install Docker. Run the following command:
sudo yum-config-manager --add-repo https://download.docker.com/linux/centos/docker-ce.repo
Step 4: Install Docker CE
After adding the Docker repository, you can install Docker Community Edition (CE) using yum. Run the following command:
sudo yum install docker-ce docker-ce-cli containerd.io -y
Step 5: Start Docker
After the installation is complete, start Docker using systemctl:
sudo systemctl start docker
To ensure Docker starts on system boot, use:
sudo systemctl enable docker
Step 6: Test the Installation
To verify that Docker has been successfully installed and started, run a Hello World container:
sudo docker run hello-world
If you see a message indicating that your Docker installation is working correctly, congratulations, you have successfully installed and started Docker on your CentOS 7!
Conclusion
Now that you have Docker installed on your CentOS 7 system, you can begin creating and managing Docker containers. Docker simplifies the development, testing, and deployment of applications by providing isolated environments for each application. For more information on working with Docker, visit the official Docker documentation.
