How to debug a running node by attaching from IntelliJ

[remyers]

Hopefully this is useful for any other Java newbies debugging Eclair.

From IntelliJ I'd like to use Run > Attach to Process... to debug a running node I launched using lightning-cfg. The eclair-alice alias launches the node with:

eclair-node.sh -Dlogback.configurationFile=$ECLAIR_LOG_CONF -Declair.datadir=.eclair/alice

From this SO post I learned that I need to create a new remote debug configuration and use the recommended configuration options highlighted in this panel:

The SO post suggests defining a JAVA_OPTS with the necessary information:

export JAVA_OPTS="-agentlib:jdwp=transport=dt_socket,server=y,suspend=n,address=*:5005"

This works for a single node, but if you want to debug multiple nodes at once, you can add this information to the command line you use to launch your nodes and use different ports for each node (ie. 5005, 5006, etc).

Works like a charm!