Creating a full docker environment on Debian 12

Fresh docker install on Debian 12 OS

Many times you may have to start developing or setting up new software on a docker environment. So i decided to write this is a quick guide to install a fresh docker setup on a Debian 12 OS. This is very important because nowadays the most of opensource software has a docker build and install, so it is so useful to be able to install it on a fresh system. In this article also a basic security strategy is put in place, just to have a good starting point for your development platform.

Basic system setup

Create underprivileged user, then add to sudo group. In this case i named “dev” this new user. You can name is as you prefer.

adduser dev
usermod -aG sudo dev

Now on exec all the process with dev user, so switch the working user to this one.

Let’s go on in installing some useful package

sudo apt-get update
sudo apt-get install git vim-nox wget ufw

Docker setup

Some parts of this setup process are described into the official docker documentations. Let’s start dis-installing packages Many t may give conflicts

for pkg in docker.io docker-doc docker-compose podman-docker containerd runc; do sudo apt-get remove $pkg; done

Set up the repository

sudo apt-get update

# Add Docker's official GPG key:

sudo apt-get install ca-certificates curl

sudo install -m 0755 -d /etc/apt/keyrings

sudo curl -fsSL https://download.docker.com/linux/debian/gpg -o /etc/apt/keyrings/docker.asc

sudo chmod a+r /etc/apt/keyrings/docker.asc

Add the docker repository to Apt sources:

echo \

  "deb [arch=$(dpkg --print-architecture) signed-by=/etc/apt/keyrings/docker.asc] https://download.docker.com/linux/debian \

  $(. /etc/os-release && echo "$VERSION_CODENAME") stable" | \

  sudo tee /etc/apt/sources.list.d/docker.list > /dev/null

sudo apt-get update

now install latest version

sudo apt-get install docker-ce docker-ce-cli containerd.io docker-buildx-plugin docker-compose-plugin

Add user dev to docker group

sudo usermod -a -G docker dev

Check if all is ok by running

$ docker ps
CONTAINER ID   IMAGE     COMMAND   CREATED   STATUS    PORTS     NAMES

You can now run your own software on docker, either building images or downloading them from the dockerhub repository.

Vim useful setting

For people using the superpowerful Vim (like me), you should enable copy/paste using the mouse. for doing that, just access the file

sudo /usr/share/vim/vim90/defaults.vim

and change the parameter mouse=a to mouse=r at line 83, then save and exit the file. Then your Vim will be ready to use with copy/paste functions using the mouse.

Some basic security setup

sudo ufw default deny incoming
sudo ufw allow 22/tcp comment 'permit SSH incoming traffic'
sudo ufw enable

now check if all is ok

sudo ufw status

You may need to enable also different ports in case of need. the procedure is the same.

In order to make a more secure connection, copy your ssh pubkey, adding it at bottom of the file ~/.ssh/authorized_keys on the server. Then

chmod 400 ~/.ssh/authorized_keys

Now you should test the SSH connection to the server using the key and then allow only a key SSH connection to the server (disallowing password connections). In order to do that, make some parameters change into the file /etc/ssh/sshd_config and set

PermitRootLogin no
PasswordAuthentication no

then restart the service

sudo /etc/init.d/ssh restart

The system is now ready (for basic purposes). In most of cases you now have a ready to go safe, docker setup, where you can develop your software, test, or run existing packages and images. If you are a professional, you may have to make additional install and settings you prefer. Enjoy