Docker Template for Rails 6

This repository serves as an educational docker template over which to build a rails app.

Special thanks to @daleal. Edited and updated by @dagalloso._

Prerequisites

• Install Docker.
• Install docker-compose (for linux).

Getting Started

• Copy files & change app name from example on Dockerfile, entrypoint.sh and docker-compose.yml to your app's name.

• Create env file:

  touch .env

• Create a rails app:

  docker-compose run web rails new . --force --no-deps --database=postgresql

• Build the Docker image:

  docker-compose build

• Get ownership of the files (on linux they are owned by root when created):

  sudo chown -R $USER: .

• Connect the database (replace the content of config/database.yml with the following, change {example} with your app's name):

  default: &default
    adapter: postgresql
    encoding: unicode
    host: db
    username: postgres
    password:
    pool: 5
  
  development:
    <<: *default
    database: {example}_development
  
  test:
    <<: *default
    database: {example}_test

• Create the database:

  docker-compose run web rails db:create

• Run the app:

  docker-compose up

• Or without logs

  docker-compose up -d

Useful Commands

• Build the Docker image:

  docker-compose build

• Start the server:

  docker-compose up

• Or without logs

  docker-compose up -d

• Stop the server:

  docker-compose down

• Run rails command (command = rails ...):

  docker-compose run web `command`

• Get ownership of files created by rails generate (on linux they are owned by root when created):

  sudo chown -R $USER:$USER .

Common errors

• Couldn't connect do Docker daemon. Fix: run the command again with sudo at the beginning (Linux problem).
• Error when creating the database. Fix: run docker-compose up, docker-compose down and run the command again.

Run an existing app

If your coworker already created the app and you want to run the existing up:

• Clone the repo.
• Build the containers (docker-compose build).
• Create the database at your computer (docker-compose run web rails db:create).
• Run the app (docker-compose up).