Debugging Rails application in Docker with byebug

During development of any application we need debugging in our application. For this rails provides many tools like byebug. Byebug stop the application inside the code.

But when you are using it with docker, we have to do some simple configuration in our docker-compose.yml file.

As we know that base requirement is to run the whole application within a container. Using docker-compose this is fairly simple. We need a compose file which covers a web container that runs the rails server command.

When using docker-compose in combination with byebug this needs to be added to make it work properly. 

So, add below code in your docker-compose.yml

web: ...
  stdin_open: true
  tty: true

Now, we have to run docker-compose in daemon mode and attach to the web container.

  
  
  $ docker-compose up -d

  $ docker attach myapp_web_1