Ruby on Rails Q & A


How to use Docker in Rails?

Docker, a platform for containerizing applications, is a powerful tool to ensure that a Rails application runs consistently across different environments. Here’s a step-by-step guide to using Docker with Rails:


  1. Dockerfile Creation:

   Begin by creating a `Dockerfile` in your Rails project’s root directory. This file describes the environment in which your Rails application will run. A basic Rails `Dockerfile` might look something like:



   FROM ruby:2.7

   RUN apt-get update -qq && apt-get install -y nodejs postgresql-client

   WORKDIR /myapp

   COPY Gemfile /myapp/Gemfile

   COPY Gemfile.lock /myapp/Gemfile.lock

   RUN bundle install

   COPY . /myapp



  1. Compose with Docker Compose:

   Docker Compose is a tool to define and manage multi-container Docker applications. For Rails, often you’ll need web and database containers. Create a `docker-compose.yml`:



   version: '3'



       image: postgres


       build: .

       command: bundle exec rails s -p 3000 -b ''


         - .:/myapp


         - "3000:3000"


         - db




  1. Build and Run:


   Use Docker Compose to build and run your application:



   docker-compose build

   docker-compose up



  1. Database Setup:

   To set up your Rails database using Docker, execute:



   docker-compose run web rake db:create



  1. Advantages:

   With Docker, you encapsulate your Rails application and all its dependencies into a container. This ensures that it runs the same, regardless of where Docker runs. It’s particularly useful for onboarding new developers, ensuring consistent staging and production environments, or scaling applications across many servers.


Integrating Docker with Rails streamlines the development process, making it more consistent and efficient. By abstracting environment specifics, Docker helps teams focus on writing code without worrying about underlying system discrepancies.

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Senior Software Engineer with a focus on remote work. Proficient in Ruby on Rails. Expertise spans y6ears in Ruby on Rails development, contributing to B2C financial solutions and data engineering.