Dockerfile

# Make sure RUBY_VERSION matches the Ruby version in .ruby-version
ARG RUBY_VERSION=3.3.6
FROM docker.io/library/ruby:$RUBY_VERSION-slim AS base

# UID and GID that will be used to run the app
# This should match the UID and GID of the user's that will run the container
ARG UID
ARG GID

# Rails app lives here
WORKDIR /rails

# Install base packages
RUN apt-get update -qq && \
    apt-get install --no-install-recommends -y curl libjemalloc2 libvips sqlite3 && \
    rm -rf /var/lib/apt/lists /var/cache/apt/archives

# Set production environment
ENV RAILS_ENV="development" \
    BUNDLE_PATH="/usr/local/bundle"

# Install packages needed to build gems
RUN apt-get update -qq && \
    apt-get install --no-install-recommends -y build-essential git libyaml-dev pkg-config && \
    rm -rf /var/lib/apt/lists /var/cache/apt/archives

# Install application gems
COPY Gemfile Gemfile.lock ./
RUN bundle install

# Run and own only the runtime files as a non-root user for security
RUN groupadd --system --gid $GID rails && \
    useradd rails --uid $UID --gid $GID --create-home --shell /bin/bash
USER $UID:$GID

# Entrypoint prepares the database.
ENTRYPOINT ["/rails/bin/docker-entrypoint"]

EXPOSE 3000

# Start server via Thruster by default, this can be overwritten at runtime
CMD ["./bin/rails", "server", "-b", "0.0.0.0"]