iEv0lv3/docker_rails_setup.md

## docker_rails_setup.md

      
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              docker_rails_setup.md
            
          
    Docker :: Rails

Setup Process

Step 1 :: Install Docker Desktop


Ensure the Docker desktop app is installed and running locally

https://www.docker.com/products/docker-desktop


if you are starting a new Rails project follow this guide

https://docs.docker.com/compose/rails/


else you are working with an existing Rails project

Proceed to Step 2


Step 2 :: Add or Edit files


Add or edit the files listed below in the Files section
Replace my_app with your application root directory name

Step 3 :: Disable Yarn Integrity


Path

config/environments/development.rb


Command to Add

config.webpacker.check_yarn_integrity = false


Result

Solves yarn not found error


Step 4 :: Build Docker Images


Build the application in Docker

Ensure your current terminal location is the my_app project root directory
$ docker-compose build


When build is complete activate the application containers in Docker

$ docker-compose up


Create the PostgreSQL database and run migrations. Open a new terminal

$ docker-compose run web rake db:create db:migrate


Step 5 :: RSpec Tests


The application should be running locally on Docker. If not please check the steps above, or start them with

docker-compose up


In a new terminal run this command

docker-compose exec web rspec


Or this alternative command (if necessary)

docker-compose run -e "RAILS_ENV=test" web rspec


Result

Solves not being able to run RSpec tests using bundle exec rspec or rspec
This will run RSpec tests using the active app and db containers


Step 6 (optional)


Follow guide for integration with CircleCI

https://gist.github.com/iEv0lv3/0d3979312791f6a64440b3d320c0bea8


Files

Dockerfile :: Add to my_app root directory

# Replace Ruby version below with your application's Ruby version. Delete this comment.
FROM ruby:2.7.1
RUN apt-get update -qq && apt-get install -y nodejs postgresql-client
RUN mkdir /my_app
WORKDIR /my_app
COPY Gemfile /my_app/Gemfile
COPY Gemfile.lock /my_app/Gemfile.lock
RUN bundle install
COPY . /my_app

# Add a script to be executed every time the container starts.
COPY entrypoint.sh /usr/bin/
RUN chmod +x /usr/bin/entrypoint.sh
ENTRYPOINT ["entrypoint.sh"]
EXPOSE 3000

# Start the main process.
CMD ["rails", "server", "-b", "0.0.0.0"]
docker-compose.yml :: Add to my_app root directory

version: '3.1'
services:
  db:
    image: postgres
    restart: always
    volumes:
      - ./tmp/db:/var/lib/postgresql/data
    environment:
      POSTGRES_PASSWORD: password
  web:
    build: .
    command: bash -c "rm -f tmp/pids/server.pid && bundle exec rails s -p 3000 -b '0.0.0.0'"
    volumes:
      - .:/my_app
    ports:
      - "3000:3000"
    depends_on:
      - db
database.yml :: Edit file located at config/database.yml

default: &default
  adapter: postgresql
  encoding: unicode
  pool: 5
  username: postgres
  password: password
  host: db
  port: 5432
entrypoint.sh :: Add to my_app root directory

#!/bin/bash
set -e

# Remove a potentially pre-existing server.pid for Rails.
rm -f /my_app/tmp/pids/server.pid

# Then exec the container's main process (what's set as CMD in the Dockerfile).
exec "$@"