Configuring a Docker Environment

Step 1: Preparation

1. System Requirements:

   • Ensure your system meets Docker’s minimum requirements, such as having a kernel version higher than 3.10 for CentOS.
   • Use the uname -r command to check your kernel version and upgrade if necessary.

2. Update Your System (Example for CentOS):

   • Execute sudo yum update to ensure your yum package manager and its dependencies are up-to-date.

Step 2: Uninstall Older Versions (if installed)

If you have older versions of Docker installed, it’s recommended to uninstall them first to avoid version conflicts.

Execute sudo yum remove docker docker-client docker-client-latest docker-common docker-latest docker-latest-logrotate docker-logrotate docker-engine to uninstall older versions.

Step 3: Set Up the Docker Repository

1. Install Necessary Tools:

   • Execute sudo yum install -y yum-utils to install yum-utils, which provides the yum-config-manager utility.

2. Add the Docker Repository:

   • Execute sudo yum-config-manager --add-repo https://download.docker.com/linux/centos/docker-ce.repo to add the new repository for Docker CE.

Step 4: Install Docker CE

1. Install Docker CE and Dependencies:

   • Execute sudo yum install docker-ce docker-ce-cli containerd.io docker-buildx-plugin docker-compose-plugin to install Docker CE, the CLI, containerd.io, and Docker Compose plugins.

2. Start the Docker Service:

   • Execute sudo systemctl start docker to start the Docker service.

3. Enable Docker on Boot:

   • Execute sudo systemctl enable docker to ensure Docker starts automatically on system boot.

Step 5: Verify Docker Installation

1. Check Docker Version:

   • Execute docker version to view the client and server version information of Docker, confirming a successful installation.

2. Pull and Run the Hello-World Image:

   • Execute docker pull hello-world to pull the Hello-World image from Docker Hub.
   • Execute docker run hello-world to run the Hello-World image, verifying Docker’s installation and operation.

Step 6: Configure Docker Mirrors (Optional)

To improve the speed of pulling Docker images, you can configure a domestic Docker mirror.

1. Create the Docker Configuration Directory:

   • Execute sudo mkdir -p /etc/docker to create the Docker configuration directory.

2. Edit the Docker Configuration File: Execute sudo tee /etc/docker/daemon.json <<-'EOF' and paste the following content (using Alibaba Cloud’s mirror as an example):

{
  "registry-mirrors": ["https://your-mirror-accel.mirror.aliyuncs.com"]
}
EOF

Replace https://your-mirror-accel.mirror.aliyuncs.com with your actual mirror address.

1. Reload Docker Configuration and Restart the Service:
   • Execute sudo systemctl daemon-reload to reload the Docker configuration.
   • Execute sudo systemctl restart docker to restart the Docker service.

Step 7: Using Docker

Your Docker environment is now set up, and you can start using Docker for containerized application development, deployment, and management. For example, you can pull official images from Docker Hub, create and run your own containers, or build custom images using Dockerfiles.

Please note that Docker’s versions and features evolve over time, so refer to the official documentation for the latest and most accurate information.