follow these instructions to have keycloack debug accessible from eclipse:
1- Simple web application
User a simple HelloServlet to try out the debugging process before applying you experience to wildfly.
1- Wildfly and eclipse
Like Thomas mentioned, Make sure you active the debug property while starting wildfly. This is independent of keycloak, as keycloak is just another web application running on wildfly. So make sure you have a simple webapp running in wildfly standalone so you can get used to the debugging process.
2- Wildfly in a docker container
Take your simple web application and wildfly into a docker container and try following:
a) Make sure you start wildfly in the container in debug mode. Not matter how you manage the docker containers in your development environment, you will have to expose their ports so you can reach the container from and outside the docker host. "Exposing the port means mapping the defined wildfly ports to some other ports on the docker host. If you are using docker-composer you have to try something like: ports:\ - "8080:8080"\ - "8787:8787". In this case see the docker-compose reference for details.
3- Accessing the docker container
Once you wildfly docker container is startet in debug mode, make sure you can access you HelloServlet from a web browser on the same machine on which you have your eclipse installed. If this works, use the same hostname or ip to replace "localhost" in you eclipse debugging config. Generally this will default to: 192.168.99.100:8787.
You did it right, you will be able to stop on the breakpoint inside your HelloServlet.
Repeat the same procedure with your custom authenticator. Do not forget to download the keycloak sources and include them in your the source path so you can navigate and set break points.