How to host a Rails + Hotwire app on Coolify

Hotwire uses Rails so this guide applies to any Rails app.

I assume you already have your Rails app working. If not, see this guide. I also assume you have Coolify set up and running.

Make a git repo

First make a repo for your project on some hosted git platform. Coolify will pull it from there.

• If you make a public repo: just copy the URL for HTTPS.
• If you make a private repo: copy the URL for SSH. You will also need to set up an SSH key for it and add it to Coolify's "Keys & Tokens" page.

Create an application in Coolify

1. Go to "Projects" in the Coolify admin panel.
2. Create a project if you didn't already.
3. Create a new resource inside it.

On the next screen ("New Resource"):

• If it's public, select "Public Repository".
• If it's private, select "Private Repository (with Deploy Key)" and on the next screen select your private key.

On the next screen ("Select a repository"):

1. Enter the repo URL you copied earlier.
2. Enter the branch name you're using (main, master, ...).
3. For Build Pack leave Nixpacks.
4. For the Port, use 3000.
5. Leave "Is it a static site?" disabled.

Configure the application.

1. Change the silly name Coolify generates into something relevant.
2. If you have a domain pointing to your server, enter it in "Domains". Use a FQDN, so include https://. Or just leave the ugly one Coolify generated.
3. Scroll down to "Network" -> "Ports Exposes" and enter 3000.
4. Click "Save" on top, otherwise it will reset.

Set up environment variables.

1. On your local machine where you have Rails, generate a rails secret. Run this in your terminal:

rails secret

Copy the output.

2. In Coolify go to "Environment Variables".
   You can use the "Developer view" on top if you like but rememer to save changes.

3. Set the following variables and use the rails secret you just generated:

RAILS_ENV=production
SECRET_KEY_BASE=your-rails-secret

You're done. Click "Deploy" on top.

Notes

To set up an SSH key, run this in your terminal:

ssh-keygen -t ed25519 -C "your description" -f ~/.ssh/example

Copy your private key form ~/.ssh/example to Coolify's Keys & Tokens settings and copy your public key from ~/.ssh/example.pub to the key settings page of the git platform you're using.