PoC Dev container Rails app

Develop and debug Rails app using Docker container.

How it works

graph LR

  Browser -- http : 3000 --> rails-server

  subgraph VSCode
    debugger
  end

  subgraph "Dev Container"
    direction TB
    rails-server["rails server (Puma)"]
    debugger -- attach : 1234 --> rdebug-ide
    rdebug-ide -- debugs --> rails-server
  end

Rails app and debugger runs inside Docker container
VSCode debugs into it with remote debugging
Rails app access via HTTP

Why?

Setup development environment quickly and consistently - minimal setup on host
Ensure dev environment closely match production (same / almost same image)

Running and debugging with VSCode

Start-up dev container (may take a while to build on first run)
```
./debug-app.sh
```
Press F5 to attach VSCode debugger to dev container
Add a breakpoint (e.g. to debugtest_controller.rb line 5)
Debug away 🙂 (e.g. go to http://localhost:3000/debugtest)

Get shell into container

To get a shell into container (e.g. to run irb / rails console):

./bash-shell-rails_debug.sh

Then run whatever command you want.

Tip: For advanced needs, use docker exec - see bash-shell-rails_debug.sh for example.

Clean-up

To stop and remove container:

./clean-up-debug-rails.sh

Optional VSCode setups

To get things like code completion, navigation ("intellisense") for VSCode, install these on host:

# Install ruby language support
vscode --install-extension rebornix.Ruby

# Enable code completion, navigation ("intellisense")
sudo gem install solargraph
vscode --install-extension castwide.solargraph