Development setup for dockerized Rails API applications.

.env_api_dev

RAILS_ENV=development

POSTGRES_ADAPTER=postgresql
POSTGRES_USER=postgres
POSTGRES_DB_NAME=sample_api_dev
POSTGRES_HOST=db
DB_PASSWORD=postgres

RAILS_LOG_TO_STDOUT=true
APP_HOME=/app/api

MEMCACHED_HOST=memcached
REDIS_URL=redis://redis:6379/0

README.md

Development setup for dockerized Rails API applications.

You can read a detailed description of the code in Driggl's blog.

Pre-requirements:

1. Docker
2. docker-compose
3. docker-sync

Put files from this gist in your brand new rails project, then run:

# build images
docker build -t Dockerfile sample/api:dev .
docker build -t Dockerfile.test sample/api:test .

# EITHER
# run the whole thing at once
docker-sync-stack start

# OR 
# run it separately

# run the file synchronization
docker-sync start

# run the whole app stack
docker-compose up -d

References

• Development Docker Cheat Sheet
• Code explanation article

Author: Sebastian Wilgosz

docker-compose.yml

version: "3"

volumes:
  sample-db-data:
  sample-redis-data:
  sample-api-sync:
    external: true

services:
  db:
    image: "postgres:10.5"
    volumes:
      - sample-db-data:/var/lib/postgresql/data
  redis:
    image: "redis:alpine"
    volumes:
      - sample-redis-data:/var/lib/redis/data
  memcached:
    image: memcached:alpine
    command: "memcached -m 500 -I 2m"
  sidekiq:
    image: sample/api:dev #can be changed to production later
    depends_on:
      - "db"
      - "redis"
      - "memcached"
    command: sidekiq -C config/sidekiq.yml
    env_file:
      - .env_api_dev
    volumes:
      - "sourcer-api-sync:/app/api:nocopy"
      - /app/api/tmp
  api:
    image: sample/api:dev
    env_file:
      - .env_api_dev
    command: /app/api/bin/start
    # command: ["/bin/sh", "-ec", "while :; do echo '.'; sleep 5 ; done"]
    volumes:
      - "sourcer-api-sync:/app/api:nocopy"
      - /app/api/tmp
    ports:
      - "3031:3000"
    depends_on:
      - "db"
      - "redis"
      - "memcached"
  specs:
    image: sample/api:test
    env_file:
      - .env_api_test
    volumes:
      - "sample-api-sync:/app/api:nocopy"
      - /app/api/tmp
    depends_on:
      - "db"
      - "redis"
      - "memcached"

docker-sync.yml

version: "2"
options:
  compose-file-path: "docker-compose.yml"

  verbose: false

  cli_mode: "auto"
  max_attempt: 5

  project_root: "config_path"

syncs:
  sample-api-sync:
    src: "."
    notify_terminal: true
    sync_excludes: ["log/*", ".sass-cache", ".gitignore", ".git", "*.dump"]

Dockerfile

# Base image
FROM ruby:2.6.5

# Installation of dependencies
RUN apt-get update -yqq \
  && apt-get install -yqq --no-install-recommends \
  build-essential \
  libpq-dev \
  nodejs \
  locales \
  && apt-get clean autoclean \
  && apt-get autoremove -y \
  && rm -rf \
  /var/lib/apt \
  /var/lib/dpkg/* \
  /var/lib/cache \
  /var/lib/log

RUN locale-gen en_US.UTF-8
ENV LANG en_US.UTF-8
ENV LANGUAGE en_US:en
ENV LC_ALL en_US.UTF-8

# Add our Gemfile
# and install gems
COPY Gemfile* /tmp/
WORKDIR /tmp
RUN bundle install

# Create a directory for our application
# and set it as the working directory
ENV APP_HOME /app/api
RUN mkdir -p $APP_HOME
WORKDIR $APP_HOME

# Copy over our application code
COPY . $APP_HOME

EXPOSE 3000

CMD bin/start

Dockerfile.test

# Base image
FROM ruby:2.6.5

# Installation of dependencies
RUN apt-get update -yqq \
  && apt-get install -yqq --no-install-recommends \
    build-essential \
    libpq-dev \
    nodejs \
    locales \
  && apt-get clean autoclean \
  && apt-get autoremove -y \
  && rm -rf \
    /var/lib/apt \
    /var/lib/dpkg/* \
    /var/lib/cache \
    /var/lib/log \
  && locale-gen en_US.UTF-8

RUN locale-gen en_US.UTF-8
ENV LANG en_US.UTF-8
ENV LANGUAGE en_US:en
ENV LC_ALL en_US.UTF-8

# Add our Gemfile
# and install gems
COPY Gemfile* /tmp/
WORKDIR /tmp
RUN bundle install

# Create a directory for our application
# and set it as the working directory
ENV APP_HOME /app/api
RUN mkdir -p $APP_HOME
WORKDIR $APP_HOME

# Copy over our application code
COPY . $APP_HOME
EXPOSE 3000

CMD bin/start