Xdebug

Xdebug can be used to set breakpoints and interactively step through requests, tests, commands, or jobs.

Listen with debugger

With an IDE supporting XDebug, get it listening on port 5089. Processes within Docker containers will not be able to reach your debugger port if it is only listening on 127.0.0.1, so make sure it is bound to 0.0.0.0 (all IPs) or any IP that will route to your workstation from inside the container (like a LAN or VPN IP).

Your debugger must also be configured to map the working tree on your workstation to the /srv/app path inside the container.

Users of Visual Studio Code can just make use of the launch config defined under /.vscode/launch.json that is ready for use with the project. Review its contents for the settings to use with any other IDE.

Install and enable PHP extension

Xdebug must be installed and enabled once per container instance:

docker-compose exec app enable-xdebug