AI

Trying to work with AI to create a ruby on rails comment system.

1. Use google ai studio, gemini 2.5 pro, turn on grounding. Discuss about the project, generate a PRD(Product Requirement Document).
2. Use VSCode insider with github copilor student free tier. Use ask mode. Feed it the PRD. It responds with a suggestion of file structure. Tell it I want to create it by hand.
3. it says:

rails new comment-system-api --api --database=postgresql
cd comment-system-api

Search online, find the ruby on rails documentation The Rails Command Line .

Install ruby on rails via nix-darwin. Seems not good. Read some resources:

• https://actually.fyi/posts/rails-on-nix/ 

Attempt #1

gem install rails

Don’t worry, that’s a joke.

• https://kristianfreeman.com/running-a-ruby-on-rails-application-in-nix 
• https://nixos.org/manual/nixpkgs/stable/#developing-with-ruby 

I’ve spend one month on NixOS and didn’t get the input method/xwayland/niri/waybar work as I expected. Maybe it is not wise to dig in “how to install rails use Nix” instead of create the product I need right now. I should focus on build.

Let’s just gem install rails.

Nah, it doesn’t work. Follow the official install_ruby_on_rails , we could use…

mise 

Wow!

Install these with nix openssl_3 libyaml gmp rustc

Official mise guide  is ambigious.

Searched on Github, trying to follow example by skyblue-jpn  to install mise with nix.

Add mise-flake.url = "github:jdx/mise"; to flake.nix inputs and outputs=inputs@.

It works! Wait… mise is just for install ruby, not rails. It also use bundle  to handle rails.

Back to start.

I have devenv installed. Maybe try to use it.

• https://upsun.com/blog/how-to-start-a-ruby-on-rails-project-with-devenv.sh/ 
• https://github.com/cachix/devenv/blob/main/examples/ruby/devenv.nix 
• https://github.com/cachix/devenv/blob/main/examples/rubyonrails/devenv.nix 
• https://discourse.nixos.org/t/issue-running-tailwind-css-with-rails-on-nixos-devenv-sh-setup/63261 

Maybe this is not a good idea, the scaffold is too complex. Docker might be better.

Decide to use nix-shell to install temporary rails, and create the project with docker. Then use that docker to work on the project.

# start the nix-shell
nix-shell -p git curl openssl_3 libyaml postgresql bundler ruby_3_4.withPackages'(ps: [ps.rails])'
 
# check ruby version
ruby --version
 
# check rails version
rails --version
 
# https://guides.rubyonrails.org/command_line.html#creating-a-rails-app
rails new --help
 
# Let's create it!
# https://supabase.com/docs/guides/getting-started/quickstarts/ruby-on-rails
rails new rails-comment --database=postgresql

Successfully created the project, but the dockerfile says it is for production, not development.

Install docker the non-nix way  .

I installed orbstack  . But maybe nothing to do with it yet?

I asked github copilot claude 3.7, created dockerfile.dev, dockerfile.prod, docker-compose.yml

And decided to use postgresql image as the database for now. It might be easier for development localy.

And use these commands:

# run the docker container
docker-compose up
 
# stop the docker container
docker-compose down
 
# build it without cache when debugging
docker-compose build --no-cache

It’s working!

Rails version: 7.2.2.1
Rack version: 3.1.13
Ruby version: ruby 3.4.3 (2025-04-14 revision d0b7e5b6a0) +YJIT +PRISM [aarch64-linux]