Dockerfile

# This Dockerfile is used as a minimum image for the Jenkins Top Submitters GitHub Action.

# We start from the golang:1.22.3-bookworm base image.
FROM golang:1.22.3-bookworm

# We declare an ARG for the GitHub token, which will be used for authentication.
ARG GITHUB_TOKEN
# We set an environment variable with the GitHub token.
ENV GITHUB_TOKEN=$GITHUB_TOKEN

# We declare ARGs for the user ID and group ID.
ARG USER_ID
ARG GROUP_ID

# We update the package lists for upgrades for packages that need upgrading, as well as new packages that have just come to the repositories.
# We install datamash, git, jq, sudo, and GitHub CLI.
# We also check if wget is installed, if not, we install it.
# We create a directory for the GitHub CLI keyring and download the keyring.
# We add the GitHub CLI repository to the sources list.
# We update the package lists again and install the GitHub CLI.
RUN apt update && apt install -y datamash git jq python3 python3-venv sudo && \
        (type -p wget >/dev/null || (sudo apt update && sudo apt-get install wget -y)) \
        && sudo mkdir -p -m 755 /etc/apt/keyrings \
        && wget -qO- https://cli.github.com/packages/githubcli-archive-keyring.gpg | sudo tee /etc/apt/keyrings/githubcli-archive-keyring.gpg > /dev/null \
        && sudo chmod go+r /etc/apt/keyrings/githubcli-archive-keyring.gpg \
        && echo "deb [arch=$(dpkg --print-architecture) signed-by=/etc/apt/keyrings/githubcli-archive-keyring.gpg] https://cli.github.com/packages stable main" | sudo tee /etc/apt/sources.list.d/github-cli.list > /dev/null \
        && sudo apt update \
        && sudo apt install gh -y

# Create a virtual environment
RUN python3 -m venv /opt/venv

# Activate the virtual environment
ENV PATH="/opt/venv/bin:$PATH"

# We create a new user called linuxbrew with home directory and zsh as default shell.
# We add the user to the sudo group.
# We create a directory for linuxbrew and change its owner to linuxbrew.
RUN useradd -m -s /bin/zsh linuxbrew && \
    usermod -aG sudo linuxbrew &&  \
    mkdir -p /home/linuxbrew/.linuxbrew && \
    chown -R linuxbrew: /home/linuxbrew/.linuxbrew

# We switch to the linuxbrew user.
USER linuxbrew

# We run the Homebrew installation script.
RUN /bin/bash -c "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/master/install.sh)"

# We switch back to the root user.
USER root

# We change the owner of the linuxbrew directory to the container user.
RUN chown -R $CONTAINER_USER: /home/linuxbrew/.linuxbrew

# We add the linuxbrew bin directory to the PATH environment variable.
ENV PATH="/home/linuxbrew/.linuxbrew/bin:${PATH}"

# We configure git to add a safe directory.
RUN git config --global --add safe.directory /home/linuxbrew/.linuxbrew/Homebrew

# We switch back to the linuxbrew user.
USER linuxbrew

# We update Homebrew and run the doctor command to check for potential problems.
RUN brew update && \
    brew doctor

# We switch back to the root user.
USER root

# We create a symbolic link from the date command to /bin/gdate.
# We tap a custom Homebrew repository.
# We install the jenkins-stats and jenkins-top-submitters packages from the custom repository.
RUN ln -s $(which date) /bin/gdate && \
    brew tap jmMeessen/tap && \
    brew install jenkins-stats && \
    brew install jenkins-top-submitters

# Create a new user with the user ID and group ID.
# If the group already exists, use the existing group.
# If the user already exists, use the existing user.
# Switch to the new user.
# This is done to ensure that the Docker container runs with the same user and group IDs as the GitHub runner,
# which helps to avoid permission issues when the Docker container writes to files that the GitHub runner needs to access.
RUN if getent group $GROUP_ID ; then groupname=$(getent group $GROUP_ID | cut -d: -f1) ; else groupadd -g $GROUP_ID runner && groupname=runner ; fi && \
    if getent passwd $USER_ID ; then username=$(getent passwd $USER_ID | cut -d: -f1) ; else useradd -l -u $USER_ID -g $groupname runner && username=runner ; fi && \
    install -d -m 0755 -o $username -g $groupname /home/runner
USER $username