Docker

Docker installation various depends upon the distribution you use check docker manual

Installing Docker Engine on Debian 11

To install Docker on Debian 11, follow these steps:

Update a Package List

Make sure your package list is up to date by opening a terminal and running the following command.

sudo apt update

Install Required Packages

Install the required packages to enable apt to use HTTPS repositories and support other package types.

sudo apt install apt-transport-https ca-certificates curl software-properties-common

Add Docker Repository

You can add Docker’s official GPG key and repository to your system by following these steps.

curl -fsSL https://download.docker.com/linux/debian/gpg | sudo gpg --dearmor -o /usr/share/keyrings/docker-archive-keyring.gpg
echo "deb [arch=amd64 signed-by=/usr/share/keyrings/docker-archive-keyring.gpg] https://download.docker.com/linux/debian $(lsb_release -cs) stable" | sudo tee /etc/apt/sources.list.d/docker.list > /dev/null

Update Package List Again

Please run the update command again to ensure that the Docker repository is included.

sudo apt update

Install Docker Engine

Install Docker Engine and its dependencies.

If you want to keep all the libraries in home directory create the symlink as follows mkdir /home/.docker/ && ln -s /home/.docker/ /var/lib/docker

sudo apt install docker-ce docker-ce-cli containerd.io

If you would like to use the docker compose plugin please add docker-compose-plugin

Start and Enable Docker

Start the Docker service and enable it to start on boot. First run the command:

sudo systemctl start docker

To automatically launch alongside the operating system, include it in the startup configuration with this command.

sudo systemctl enable docker

Verify Installation

To ensure that Docker is up and running, try running a basic container with a “Hello World” command.

sudo docker run hello-world

Congratulations! You have successfully installed Docker on Debian 11. Get ready to efficiently manage and run containers for your applications.

Enable TCP port 2375 for external connection to Docker

Update the systemd configuration

Locate the docker daemon service file in my case /lib/systemd/system/docker.service

❯ systemctl status docker
● docker.service - Docker Application Container Engine
     Loaded: loaded (/lib/systemd/system/docker.service; enabled; preset: enabled)
    Drop-In: /usr/lib/systemd/system/docker.service.d
             └─dietpi-simple.conf
     Active: active (running) since Wed 2024-03-27 23:10:33 IST; 1 week 2 days ago
TriggeredBy: ● docker.socket
       Docs: https://docs.docker.com
   Main PID: 1451697 (dockerd)
      Tasks: 67
     Memory: 48.3M
        CPU: 1h 13min 47.364s
     CGroup: /system.slice/docker.service

locate the ExecStart and update the tcp lisen port as follows

ExecStart=/usr/bin/dockerd -H fd:// --containerd=/run/containerd/containerd.sock -H=fd:// -H=tcp://0.0.0.0:2375

Reload the systemd daemon:

systemctl daemon-reload

Restart docker:

 systemctl restart docker.service

Verify TCP port

You can verify if the docker is lisening on the port 2375

❯ ss -lntp | grep 2375
LISTEN 0      4096               *:2375             *:*    users:(("dockerd",pid=1451697,fd=3))

Manage Docker as a non-root user

The docker group grants root-level privileges to the user. For details on how this impacts security in your system, see Docker Daemon Attack Surface.

Create the docker group and add your user:

sudo groupadd docker

Add your user to the docker group.

sudo usermod -aG docker $USER

Log out and log back in so that your group membership is re-evaluated.

If you’re running Linux in a virtual machine, it may be necessary to restart the virtual machine for changes to take effect.

You can also run the following command to activate the changes to groups:

newgrp docker

Verify that you can run docker commands without sudo.

docker run hello-world