Cannot debug Websphere Application Server inside of a Docker container using IntelliJ

I am trying to move a WAS into a container, and continue to have the ability to debug it. It is a traditional WAS version 8.5.5.17. I've tried multiple things, but I cannot successfully attach a remote debugger using IntelliJ. The WAS is set to debugMode when looking through the server.xml, but there is no listening port. The JVM properties related to debugging are set as follows:

debugMode="true" debugArgs="-agentlib:jdwp=transport=dt_socket,server=y,suspend=n,address=7777" genericJvmArguments=""

Dockerfile:

FROM ibmcom/websphere-traditional:8.5.5.17

COPY db /work/config/db
COPY MQ /work/config/MQ
COPY earear /work/config/ear.ear
COPY custom_jvm_properties.txt /work/config/custom_jvm_properties.txt
COPY file.properties /work/config/file.properties
COPY Sscript.py /work/config/Script.py
COPY jars/work/config/jars
RUN mkdir -p /work/config/Folder

RUN /work/configure.sh

#ENV JAVA_TOOL_OPTIONS -agentlib:jdwp=transport=dt_socket,server=y,suspend=n,address=7777
EXPOSE 80 9080 9448 9443 9060 9043 7777

When I build the image using the above file, the container builds and the application can be ran. Uncommenting out the #ENV line results in the image being built, but running the container results in the following error:

ERROR: transport error 202: bind failed: Address already in use
ERROR: JDWP Transport dt_socket failed to initialize, TRANSPORT_INIT(510)
JDWP exit error AGENT_ERROR_TRANSPORT_INIT(197): No transports initialized [debugInit.c:762]

My docker run command is as follows:

docker run -p 80:80 -p 9080:9080 -p 9448:9448 -p 9443:9443 -p 9060:9060 -p 9043:9043 -p 7777:7777 -v C:\volume:/volume --name ContainerName image

Trying to pass the JAVA_TOOL_OPTIONS as an environmental variable does not work either. At this point I can start the server in debug mode, but not have any listening ports to attach a debugger to, or the server fails to start with listening ports because of the above error.

Instead of providing your debug options using

#ENV JAVA_TOOL_OPTIONS -agentlib:jdwp=transport=dt_socket,server=y,suspend=n,address=7777

I believe the recommended procedure would be to put these debug options within a properties file (debug.props) under:

debugArgs="-agentlib:jdwp=transport=dt_socket,server=y,suspend=n,address=7777"

Then copy to your docker image:

COPY --chown=was:root debug.props /work/config/debug.props

Finally, apply this config:

RUN work/applyConfig.sh /work/config/debug.props

See sample project here: https://github.com/WASdev/ci.docker.websphere-traditional/tree/10367b51ccbf489cd6e1655769b968e9d9bfca13/samples/batch-compute-grid

Managed to figure it out after playing around with IntelliJ.

I was trying to follow this guide https://blog.jetbrains.com/idea/2019/04/debug-your-java-applications-in-docker-using-intellij-idea/

However, it took some additional set-up. I had to configure the websphere image to build and set it to always start in debug mode (May cause slow-downs further along, but this was a workaround that allows me to debug and can be removed when rebuilding the image). After this, I could only attach the remote debugger once the server was completely started. There was no prompt that the server had an available port to listen to, but it did. Using the "Launch docker before debug" option would result in a failure to attach. Thanks for the help!