Example Rails Application

Develop an example Rails application and deploy it to Heroku.

Useful Link

Step-by-step tutorial on deploying a Rails application to Heroku

Please use this README as a supplement to the above tutorial. The reason is that only following the above tutorial does not work for me.

Prerequisites

ruby -v
ruby 3.1.2p20 (2022-04-12 revision 4491bb740a) [x86_64-linux]

rails -v
Rails 6.1.5

node -v
v16.18.1

yarn -v
1.22.19

Please also install PostgreSQL, Git, and Heroku CLI on your local machine.

Step 1 - Local Setup

Log in to Heroku via the Terminal. If you have enabled Multi-Factor Authentication (MFA), use your Heroku API Key as the password. You can find your API key in Account Settings.

heroku login

Use the Rails new application generator to create a Rails application.

rails _6.1.5_ new example-app --database=postgresql

cd example-app/

bundle lock --add-platform x86_64-linux --add-platform ruby

code .

Modify the content of config/database.yaml . Please refer to config/database.yaml provided by this repository.

Note that it may not work on your local machine. My local machine is Ubuntu 22.04.1.

Create two local databases.

bin/rails db:create

Define a hello action in ApplicationController and set the route to map the root to that controller action. Please refer to app/controllers/application_controller.rb and config/routes.rb.

Start the Puma server.

bin/rails server

Go to http://localhost:3000/. Hello, world!

Step 2 - Deployment Preparation

Create a Procfile in the root directory of the project.

web: bundle exec puma -C config/puma.rb

Fix babel regression errors. Your application may contain bugs! Try executing the following command in Terminal.

rake webpacker:clobber webpacker:compile  2>&1 | grep "Cannot find package '@babel/plugin-proposal-private-methods'"
Error: Cannot find package '@babel/plugin-proposal-private-methods' imported from /home/quanchic/Desktop/RailsLearning/example-app/babel-virtual-resolve-base.js

No worries. Let's fix the errors. Open babel.config.js.

Replace @babel/plugin-proposal-private-methods with @babel/plugin-transform-private-methods.

Replace @babel/plugin-proposal-private-property-in-object with @babel/plugin-transform-private-property-in-object.

Hopefully, the following command now works!

rake webpacker:clobber webpacker:compile

Also, please specify the Node.js version used by Heroku. Add the following code to package.json.

"engine": {
  "node": "16.18.1"
}

Commit the code.

git add -A

git commit -m "Initialise repository"

git log

Step 3 - Deployment

Create a Heroku application.

heroku create --stack heroku-20

git remote -v

Provision a non-free database.

heroku addons:create heroku-postgresql:mini

Wait a minute. Before deploying the code to Heroku, we need to execute a few more commands.

heroku buildpacks

heroku buildpacks:set heroku/nodejs -i 1

heroku buildpacks:set heroku/ruby -i 2

heroku buildpacks

heroku config:set NODE_OPTIONS=--openssl-legacy-provider

For the last command, you may have a look at this issue. You may skip executing that command and see if Heroku gives a similar error.

Deploy the application to Heroku.

git push heroku master

Now we are at the end of this amazing journey!

Step 4 - Finally

Remove the database and the application from your Heroku account to minimise the cost.

heroku addons:destroy heroku-postgresql

heroku apps:destroy

heroku addons --all

heroku apps --all

Goodbye! Enjoy coding and deploying!