A dockerized Python Development Environment

This summerizes my notes during playing with docker, building an ubuntu environment.

Motivation

On our Window PC, we like to have an Linux environment, for

• Unix file management workflow,
• scripting and
• Python development.

We will not use WSL neither WSL2, but Docker - this, we can transfer to another host system - to provide an image and a container that offer a Linux environment, with

• TTY only
• work as a user, e.g. docker, including sudo rights
• with its home directory /home/docker
• that /home/docker shall be directly accessible from the host system's native tools, e.g. via File Explorer:
  • at a defined directory, by docker bind or volume (works_)
  • at a Windows drive letter, by Unix Samba (t.b.d.)
• the environment shall be usable via VScode and Windows PowerShell
• use zsh a shell, including auto_complete & auto_suggestion
• provide fancy prompt with p10k and font MesloLGS Nerd Font Mono

Installation

Let us create a docker image from ubuntu, so that docker will provide a docker container that we can use as our Python Development Environment and some Unix Scripting.

Prerequisites - installation on local host OS (e.g. Windows):

1. Docker Desktop
   • for Windows see: Install Docker Desktop on Windows
   • for Mac, see: Install Docker Desktop on Mac
   • for Linux, see: Install Docker Desktop on Linux
2. VScode, see: Download Visual Studio Code

Define some folders for our working environment by chosing any folder at your host machine OS (e.g. Windows) and create a structure like:

PythonEnv_with_Ubuntu_Docker/
|-- .dockerignore
|-- Dockerfile
\-- README.md

home_docker/       # anywhere at your host
| 
|   **************************************
|   * This is the                        *
|   *    my_ubuntu_cont: /home/docker/   *
|   *    --> host: home_docker/          *
|   **************************************

The ubuntu_cont with its user docker will use a dedicated bind volume, i.e. the users directory /home/docker/ that is linked to the host's OS (e.g. Windows) directory home_docker/.

Build a new image with a Dockerfile

1. Go to directory with Dockerfile, e.g. docker/ubuntu/

   PythonEnv_with_Ubuntu_Docker/      # go here
   |-- .dockerignore
   |-- Dockerfile
   \-- README.md

2. check the content of the Dockerfile:

   FROM ubuntu:latest
   
   # see: https://stackoverflow.com/questions/36611052/install-pip-in-docker
   RUN DEBIAN_FRONTEND=noninteractive \
   apt-get update && apt-get -y install \
       zsh \
       git curl wget lynx \
       iputils-ping lshw net-tools \
       nano bc gawk htop eza fzf bat neovim stow \
       sudo \
       python3.12 python3-pip pipenv \
       tzdata \
       unminimize
   
   # correct timezone
   ENV TZ=Europe/Berlin
   RUN ln -snf /usr/share/zoneinfo/$TZ /etc/localtime && echo $TZ > /etc/timezone
   
   # --------------------------- user:passwd
   RUN useradd docker && echo "docker:docker" | chpasswd
   RUN usermod --shell /usr/bin/zsh -aG sudo docker
   RUN usermod --shell /usr/bin/zsh -aG sudo root
   # ------------------------------------- user:group
   RUN mkdir -p /home/docker && chown -R docker:docker /home/docker
   
   USER root
   RUN zsh

3. Build a new image ubuntu_img and tag it (-t) with new image name:

   docker build -t ubuntu_img .   # notice the dot at the end

   You can see all images, with:

   docker image ls

   REPOSITORY    TAG    IMAGE ID     CREATED        SIZE
   mubuntu_img   latest daedc675771f 30 minutes ago 947MB

Create a new container from the ubuntu_img

To create a container ubuntu_cont for the user docker that is at a directory of your host (e.g. Windows): Go to host's directory _home_docker/ !!

PythonEnv_with_Ubuntu_Docker/
|-- .dockerignore
|-- Dockerfile
\-- README.md

home_docker/       # go here
| 
|   **************************************
|   * This is the                        *
|   *    my_ubuntu_cont: /home/docker/   *
|   *    --> host: home_docker/          *
|   **************************************

Proceed with create the container, if you are here:

PS ...\docker\home_docker>

for Windows PS or cmd prompt, a one-liner

docker container create -it --name ubuntu_cont --user docker -v $PWD/:/home/docker ubuntu_img zsh

for Unix/Mac cmd prompt, multiple lines

docker container create -it \
    --name ubuntu_cont \
    --user docker \
    -v $PWD/:/home/docker \
    ubuntu_img \
    zsh

After installation tasks can be:

Changes in a running container will only stay as long as the container ist up and running. If you stop the container, that changes will be lost with the next re-start, but you can commit a container and build a new image from that container (see: docker container commit), with this all your changes will stay.

Changes that are done in a volume or a bind location - as we do here for user docker - will stay and be there after re-starting the container.

1. You may unminimize the ubuntu installation by

sudo unminimize

2. Sometimes you like to reconfigure the prompt, do so by

p10k configure

Ensure that the MesloLGS Nerd Font Mono ist configured at your PS and VScode

• PS: Go to Einstellungen > Standardwerte > Darstellung > Schriftart > set to: MesloLGS Nerd Font Mono
• VScode: Goto File > Preferences > Settings > at "Search settings" input: Terminal:Integrated:Font > set to: MesloLGS Nerd Font Mono

3. Oh-my-zsh and some plugins

   • see: Oh-my-zsh
   • see: Oh my zsh - with some plugins

Start a container

If you already have a container ubuntu_cont:

Note:

the container ubuntu_cont knows: it will use the volume, defined with

-v $PWD/:/home/docker

or

-v home_docker_vol:/home/docker

so you do NOT need to start at a dedicated host's directory (as with step 1.)

Start ubuntu_cont with

docker start ubuntu_cont

If container is running: exec with login:

docker exec -it ubuntu_cont login

Alternatives, but NOT prefered - use existing container ubuntu_cont

After ubuntu_cont is running, you can attach to, with: docker attach ubuntu_cont and your prompt will show:

PS ... \docker\home_docker> docker start ubuntu_cont
ubuntu_cont
PS ... \docker\home_docker> docker attach ubuntu_cont
╭─ ∅ / ───────────────────────────────────────────────────────────────── 
╰─❯ cd
╭─ ~ ─────────────────────────────────────────────────────────────────── 
╰─❯    

1. Start the container from

   • PS or VScode Terminal prompt (aka command line) with: docker start ubunut_cont

   • inside VScode:

     

   PS ... \docker\home_docker> docker start ubuntu_cont
   ubuntu_cont

2. Attach - better exec - to a running container via

   • PS or VScode Terminal prompt (aka command line) with: docker attach ubunut_cont

   • inside VScode:

     

   PowerShell 7.4.6
   PS ... > docker start ubuntu_cont
   ubuntu_cont    
   PS ... > docker exec -it ubuntu_cont login
   e4215510551d login: docker
   Password: docker
   Welcome to Ubuntu 24.04.1 LTS (GNU/Linux 5.15.153.1-microsoft-standard-WSL2 x86_64)
   
   * Documentation:  https://help.ubuntu.com
   * Management:     https://landscape.canonical.com
   * Support:        https://ubuntu.com/pro
   ╭─   ~ ───────────────────────────────────────────────────────────────
   ╰─❯ <ENTER>
   ╭─   ~ ───────────────────────────────────────────────────────────────
   ╰─❯ 

Create image from a container

Sometimes you like to make your own image from the container that you are working with - Google docker commit

Open Items:

# TODO: 

# TODO: 
#