How to install docker on linux

With the rise of container technology, Docker has become the most popular container engine. It can quickly build, deploy, and run applications with a high degree of flexibility and portability. Installing Docker in a Linux environment is very easy, and this article will show you how to install Docker on Linux.

Step 1: Check whether the system meets the requirements

Before installing Docker, we need to check whether the current Linux system version meets the requirements. Docker only supports 64-bit operating systems, and the kernel version needs to be 3.10 or above. You can check the kernel version by running the following command:

uname -r

If your system's kernel version is lower than 3.10, then you need to upgrade to a newer version.

Step 2: Uninstall old versions of Docker

If you have installed old versions of Docker before, you need to uninstall them. You can uninstall by running the following command:

sudo apt-get remove docker docker-engine docker.io containerd runc

Step 3: Install Docker CE

You can use the official installation script to install Docker CE. You can download this script to your system using the following command:

curl -fsSL https://get.docker.com -o get-docker.sh

Run the following command to start the Docker installation:

sudo sh get-docker.sh

This command will download and install Docker CE, along with the necessary dependencies and tools. The installer should automatically set the Docker service as one of the Linux system boot items and start the Docker service.

Step 4: Verify Docker installation

After completing the installation, you need to verify whether Docker is installed correctly. You can run the following command to verify the installation:

sudo docker run hello-world

If Docker installed correctly, you will see the following output:

Hello from Docker!
This message shows that your installation appears to be working correctly.

Step 5: Run Docker using a non-root user

In order To use Docker more safely, we recommend that you do not run Docker under the root user. You can create a group named docker and add a non-root user to the group to allow that user to manage Docker. Additionally, the Docker daemon can be set up to only accept requests to the Docker API via Unix sockets. This can be done by running the following command:

sudo groupadd docker
sudo usermod -aG docker $USER
sudo systemctl restart docker

Step 6: Using Docker

Now you have successfully installed Docker on your Linux system and set up access permissions for non-root users. You can find and download any container image on Docker Hub and run the container using the following command:

sudo docker run [OPTIONS] IMAGE [COMMAND] [ARG...]

For example, if you want to run an ubuntu image and run a bash terminal in it, you can use the following command:

sudo docker run -it ubuntu /bin/bash

The above command will start a container named ubuntu and start an interactive shell in it. At this point, you can execute any command in it.

You can use the following command to list currently running containers:

sudo docker ps

If you want to stop a running container, please use the following command:

sudo docker stop [CONTAINER ID]

Notes

• During the installation of Docker, the installation script will add the Docker apt repository and use the apt package manager to install Docker.
• Docker relies on cgroups and namespace features, so these features need to be enabled in the Linux kernel to function properly.
• If you are using an Ubuntu system, you can visit Canonical's Docker installation documentation for detailed installation instructions and recommendations.
• If you are using an RPM package manager-based system such as Red Hat Enterprise Linux or CentOS, you can visit Docker's RHEL installation documentation for detailed installation instructions and recommendations.

Conclusion

Docker is one of the most powerful container engines that can quickly build, deploy, and run applications with a high degree of flexibility and portability. On Linux systems, installing Docker is a very simple process, just download the official installation script and run it. After installation, you can use any container image on Docker Hub and easily manage containers using simple commands.

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