Create a Rails App Using Docker

The Rails Charlotte Group previously offered a Rails class to our community.

In creating the class, we could not find any up-to-date, solid installation process for creating a new Rails App.

So, we’ve create this Rails Setup repo to help students get started with their first Rails app.

This setup uses Docker and docker-compose to build and maintain a Rails application.

Step 1: Prerequisites

The following software needs to be installed on your computer before you can start

• Docker: https://www.docker.com/products/docker-desktop
• Git: https://git-scm.com/book/en/v2/Getting-Started-Installing-Git
• Visual Studio Code: https://code.visualstudio.com
  • We recommend Visual Studio Code because it comes with a built-in terminal. You don’t have to use Visual Studio Code. You are welcome to use any coding editor/terminal you are comfortable with. Just keep in mind, these instructions will be using Visual Studio Code.

Step 2: Clone Setup Files

You will need to create a new folder on your computer. You can place that folder in any location you want on your computer. You can also name the folder anything you want. I am going to name the folder LearnRails

Once you have created the empty folder, open the folder in Visual Studio Code.

In Visual Studio Code, click on Terminal and New Terminal.

In your newly opened terminal, run

git clone https://github.com/railscltgroup/rails_setup_docker_compose.git

Once you run this command, a new fold should appear called rails_setup_docker_compose This folder will have all the Rails and Docker files needed to create your first app.

run

cd rails_setup_docker_compose

To move your terminal into the new folder

Step 3: Build a new Rails App in Docker

First, make sure you have Docker running on your computer. You can type docker info in your terminal to see that it is working.

Once Docker is running, run the following command in your terminal

docker build --build-arg APP_NAME=myapp -f setup/createNewApp.Dockerfile -t web .

This command will use the file rails_setup_docker_compose/setup/createNewApp.Dockerfile to install Rails software and build a new Rails app named myapp. It may take awhile to install and build.

Step 4: Create a temp docker container

run

docker create --name temp-app web

To create a temporary container in docker.

Step 5: Copy your new Rails app to your computer

run

docker cp temp-app:/docker-build/myapp ./

to copy the Rails application from your temporary docker container, to your computer.

A new folder should appear in your rails_setup_docker_compose. That new folder is your Rails App. You can choose to keep is in the rails_setup_docker_compose, or you can move it to another location on your computer.

Step 6: Remove the temp container

run

docker rm temp-app

To delete the temporary container from docker

Step 7: Remove the setup image

run

docker image rm web

To delete the setup image from docker.

Step 8: Checkout your new app

You have created a new Rails App!

This means you are done with the setup folder. You can keep it or remove it from your computer. It’s your choice!

Next, you want to use Visual Studio Code to open the myapp folder you just created

You’ll also need to click on Terminal and New Terminal to open a terminal in your app.

Feel free to checkout the files and app you just created!

Step 9: Setup app and database

You already built software to create the app. You have not yet built software to run the app.

run

docker-compose run --rm web rails db:create db:migrate

to build app software and create a database. This may take awhile to finish.

Step 10: View your new app in the browser

run

docker-compose up

and visit http://localhost:3000/ in your browser.

If your app is working, you should see the Rails logo on the webpage.

Congratulations! You’ve made a Rails application!

Checkout (https://railsclt.com/learn) for next steps and additional tutorials.

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Turn off your Rails App

Docker will keep running in the background on your computer. If you don’t turn it off, it may drain your battery.

When you are done working on your app, make sure to run

docker-compose down

This will not delete your docker images, but it will shut down a lot of running processes.

When you are ready to turn it back on, run

docker-compose up

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Delete your app

If you are done working on the app and you want to delete all docker images from your computer, run the following commands in your terminal

Delete your database

run

docker-compose run --rm web rails db:drop

Turn off docker app processes

run

docker-compose down

Delete all docker images that contain the name “web”

run

docker image rm $(docker images | grep 'web')

Delete all docker images that contain the name “ruby”

run

docker image rm $(docker images | grep 'ruby')

Delete all docker images that contain the name “postgres”

run

docker image rm $(docker images | grep 'postgres')

Delete any dangling docker volumes

run

docker volume rm $(docker volume ls -qf dangling=true)

Delete myapp folder from your computer