Example of local docker configuration for simple RoR application

docker-compose.yml

version: "3.8"

services:
  db:
    image: postgres:11-alpine
    environment:
      POSTGRES_USER: ${DOCKER_POSTGRES_USER}
      POSTGRES_PASSWORD: ${DOCKER_POSTGRES_PASSWORD}
    ports:
      - '5434:5432'
    volumes:
      - ./tmp/db:/var/lib/postgresql/data

  web:
    build:
      target: web
    command: bash -c "bundle check || bundle install && rails s -b 0.0.0.0 -p 3003"
    environment:
      SSH_AUTH_SOCK: /ssh-agent
    ports:
      - '3000:3003'
    volumes:
      - .:/app
      - bundle_cache:/bundle_cache
      - ${HOST_SSH_SOCKET_PATH}:/ssh-agent
    <<: &default
      platform: linux/amd64
      build:
        context: .
        dockerfile: Dockerfile
      tty: true
      stdin_open: true
      depends_on:
        - db

  job:
    <<: *default
    build:
      target: job
    command: bash -c "bundle check || bundle install && bundle exec rake jobs:work"
    volumes:
      - .:/app
      - bundle_cache:/bundle_cache

  bundle_cache:
    image: busybox
    volumes:
      - bundle_cache:/bundle_cache

volumes:
  bundle_cache:

Dockerfile

FROM ubuntu:22.04 AS build

SHELL ["/bin/bash", "-c"]

ENV RUBY_MAJOR 3.2
ENV RUBY_VERSION 3.2.2

# Default directory
ENV WORKING_PATH /app
RUN mkdir -p $WORKING_PATH

# Prepare to install tzdata
ARG DEBIAN_FRONTEND=noninteractive
ENV TZ=America/New_York

# No output except for errors
RUN apt-get update -qq && apt-get install -y wget gnupg cmake g++ file sudo pkg-config imagemagick libtool\
                                             libpq-dev postgresql-client git gawk bison libffi-dev libgdbm-dev tzdata\
                                             libncurses5-dev libsqlite3-dev libyaml-dev sqlite3 zlib1g-dev libgmp-dev libreadline-dev

# https://github.com/git/git/commit/8959555cee7ec045958f9b6dd62e541affb7e7d9
RUN git config --global --add safe.directory $WORKING_PATH

# Install ruby (download and compile from source)
RUN wget -O ruby.tar.gz "https://cache.ruby-lang.org/pub/ruby/${RUBY_MAJOR}/ruby-$RUBY_VERSION.tar.gz"; \
    mkdir -p tmp/src/ruby; \
    tar -xzf ruby.tar.gz -C tmp/src/ruby --strip-components=1; \
    rm ruby.tar.gz; \
    cd tmp/src/ruby; \
    ./configure --disable-install-doc; \
    make; \
    make install
RUN rm -r tmp/src/ruby; \
    ruby --version; \
    gem --version; \
    bundle --version

ENV BUNDLE_SILENCE_ROOT_WARNING=1
ENV BUNDLE_PATH /bundle_cache
ENV PATH="$WORKING_PATH/bin:${PATH}"
WORKDIR $WORKING_PATH

RUN gem update --system --no-document


FROM build as web

# Yarn installation deps
RUN wget -O- https://dl.yarnpkg.com/debian/pubkey.gpg | gpg --dearmor | tee /etc/apt/keyrings/yarn-pubkey.gpg > /dev/null
RUN echo "deb [signed-by=/etc/apt/keyrings/yarn-pubkey.gpg] https://dl.yarnpkg.com/debian/ stable main" | \
        tee /etc/apt/sources.list.d/yarn.list

RUN wget -qO- https://deb.nodesource.com/setup_14.x | bash -

RUN apt-get update -qq && apt-get install -y nodejs yarn
RUN yarn install

## Integration tests configuration

# Installation firefox via apt is a little bit tricky thing
RUN apt-get -y install software-properties-common; \
    add-apt-repository -y ppa:mozillateam/ppa
RUN echo $' \n\
Package: *\n\
Pin: release o=LP-PPA-mozillateam\n\
Pin-Priority: 1001' | tee /etc/apt/preferences.d/mozilla-firefox
RUN apt-get -y install firefox

# Install chromium
RUN apt purge chromium-browser chromium-chromedriver; \
    apt-get install debian-archive-keyring
RUN echo $'deb [signed-by=/usr/share/keyrings/debian-archive-keyring.gpg] http://deb.debian.org/debian buster main\n\
deb [signed-by=/usr/share/keyrings/debian-archive-keyring.gpg] http://deb.debian.org/debian-security/ buster/updates main\n\
deb [signed-by=/usr/share/keyrings/debian-archive-keyring.gpg] http://deb.debian.org/debian buster-updates main' | \
    tee /etc/apt/sources.list.d/debian.list

RUN echo $' \n\
Explanation: Allow installing chromium from the debian repo.\n\
Package: chromium*\n\
Pin: origin "*.debian.org"\n\
Pin-Priority: 100\n\
\n\
Explanation: Avoid other packages from the debian repo.\n\
Package: *\n\
Pin: origin "*.debian.org"\n\
Pin-Priority: 1' | tee /etc/apt/preferences.d/chromium.pref

RUN apt-get update && apt-get -y install chromium

EXPOSE 3003

# Run a server
CMD ["rails", "server", "-b", "0.0.0.0", "-p", "3003"]


FROM build as job

# Run jobs
CMD ["bundle", "exec", "rake", "jobs:work"]