How to debug a rails app in docker with pry?
If you're using docker-compose, you can add these flags to docker-compose.yml:
app: tty: true stdin_open: trueAnd then attach to your process with docker attach project_app_1. pry-rails works here now. Ensure less is installed on your container for the optimal pry experience.
cf. https://github.com/docker/compose/issues/423#issuecomment-141995398
to use pry you have to run it differently:
docker-compose run --service-ports web
check out this article for more info:
as Gabe Kopley answer, assume your rails container is called app, set stdin_open and tty to true:
app: stdin_open: true tty: trueand I wrote a bash script to make life easier, save it to bin/dev:
#!/bin/bashdocker-compose up -d && docker attach $(docker-compose ps -q app)don't forget to make dev be executable by chmod +x bin/dev
In your terminal, type bin/dev, it will automatically run up containers and attach the app container. when binding.pry called, you can type to the terminal directly.