My Docker development shell

21 Dec 2021

I just made a simple docker container to use as a development shell. This will make it easier and faster for me to just build the docker container and run it when I need a development shell environment.

Dockerfile

I will base my Docker container on Debian bullseye because I mostly run Debian.

FROM debian:bullseye

Simple start, my next step was to make sure my environment is setup as I want it. US English as language, but with my Swedish locale for everything else time, date etc.

# Variables
ARG LOCALE="sv_SE.UTF-8"
ENV TZ=Europe/Stockholm

# Install locales and make sure tzdata exists
RUN apt-get update && apt-get install -y locales tzdata
RUN sed -i "/en_US.UTF-8/s/^#//g" /etc/locale.gen
RUN sed -i "/sv_SE.UTF-8/s/^#//g" /etc/locale.gen
RUN locale-gen

ENV LANG="en_US.UTF-8" \
    LANGUAGE="en_US:en" \
    LC_NUMERIC="$LOCALE" \
    LC_TIME="$LOCALE" \
    LC_COLLATE="$LOCALE" \
    LC_MONETARY="$LOCALE" \
    LC_PAPER="$LOCALE" \
    LC_NAME="$LOCALE" \
    LC_ADDRESS="$LOCALE" \
    LC_TELEPHONE="$LOCALE" \
    LC_MEASUREMENT="$LOCALE" \
    LC_IDENTIFICATION="$LOCALE"

RUN update-locale

ARG is a local variable in Dockerfile and is not available in the Docker container when it is running
ENV is an environment variable and will be available in the Docker container when it is running.

I’m using the ARG to create a local LOCALE variable for easy change of the locale for everything except language.

The next step is to set the timezone

# Timezone
RUN echo $TZ > /etc/timezone
RUN rm /etc/localtime && ln -snf /usr/share/zoneinfo/$TZ /etc/localtime && \
    dpkg-reconfigure -f noninteractive tzdata

Finally it’s time to install some basic stuff and some dev packages

# Install dev packages
RUN apt-get install -y \
    build-essential \
    wget \
    curl \
    git \
    nano

# Install Node.js 16.x
RUN curl -sL https://deb.nodesource.com/setup_16.x | bash -
RUN apt-get install -y nodejs

# Install yarn
RUN npm install --global yarn
RUN npm install --global gulp

And yes I am running nano, I don’t know how to quit from vi..

Complete Dockerfile

FROM debian:bullseye

# Variables
ARG LOCALE="sv_SE.UTF-8"
ENV TZ=Europe/Stockholm

# Install locales and make sure tzdata exists
RUN apt-get update && apt-get install -y locales tzdata
RUN sed -i "/en_US.UTF-8/s/^#//g" /etc/locale.gen
RUN sed -i "/sv_SE.UTF-8/s/^#//g" /etc/locale.gen
RUN locale-gen

ENV LANG="en_US.UTF-8" \
    LANGUAGE="en_US:en" \
    LC_NUMERIC="$LOCALE" \
    LC_TIME="$LOCALE" \
    LC_COLLATE="$LOCALE" \
    LC_MONETARY="$LOCALE" \
    LC_PAPER="$LOCALE" \
    LC_NAME="$LOCALE" \
    LC_ADDRESS="$LOCALE" \
    LC_TELEPHONE="$LOCALE" \
    LC_MEASUREMENT="$LOCALE" \
    LC_IDENTIFICATION="$LOCALE"

RUN update-locale

# Timezone
RUN echo $TZ > /etc/timezone
RUN rm /etc/localtime && ln -snf /usr/share/zoneinfo/$TZ /etc/localtime && \
    dpkg-reconfigure -f noninteractive tzdata

# Install dev packages
RUN apt-get install -y \
    build-essential \
    wget \
    curl \
    git \
    nano

# Install Node.js 16.x
RUN curl -sL https://deb.nodesource.com/setup_16.x | bash -
RUN apt-get install -y nodejs

# Install yarn
RUN npm install --global yarn
RUN npm install --global gulp

Helper scripts

Some helper scripts because I don’t always remember how to use stuff.

Build script

Super simple bash script to build the docker container

#!/bin/bash

docker build -t docker-dev-shell .

This way I don’t have to remember how to build the container. I just have to clone my repo and run ./build.sh to build the container

Run script

If I can’t remember how to build the container, I can’t remember how to run it. So I need a script to run the container as well. This script is a bit more complex because I made the script to run the container as the current user, with the current users home folder mounted as persistent storage.

#!/bin/sh

UID=$(id -u)
GID=$(id -g)

docker run \
       --user $UID:$GID \
       -v /etc/group:/etc/group:ro \
       -v /etc/passwd:/etc/passwd:ro \
       -v /etc/shadow:/etc/shadow:ro \
       -v /home/$USER:/home/$USER \
       --workdir="/home/$USER" \
       --hostname dev-shell \
       -it --rm docker-dev-shell

–user Parameter will run the docker container as the current user
-v /etc/* Parameters will mount the local passwd,group,shadow files from host, so the local user will be available in the container.
-v /home/$USER Parameter will mount the current user Home folder to use as persistent storage.
–hostname Parameter gives the container an internal hostname, just to make the interactive prompt have a pretty hostname. Makes it clear we are in a dev-shell as well.
-it –rm Parameters will create an interactive container and will remove it when we exit so make sure you save your stuff in your home folder.