debug-cnb

debug-cnb

The Cloud Foundry Debug Buildpack is a Cloud Native Buildpack V3 that enables the debuging of JVM applications.

Detection

The detection phase passes if

• $BP_DEBUG exists and build plan contains jvm-application
  • Contributes debug to the build plan

Build

If the build plan contains

• debug
  • Contributes debug configuration to $JAVA_OPTS
  • If $BPL_DEBUG_PORT is specified, configures the port the debug agent will listen on. Defaults to 8000.
  • if $BPL_DEBUG_SUSPEND is specified, configures the JVM to suspend execution until a debugger has attached. Note, you cannot ssh to a container until the container has decided the application is running. Therefore when enabling this setting you must also push the application using the parameter -u none which disables container health checking. Defaults to n.

Creating SSH Tunnel

After starting an application with debugging enabled, an SSH tunnel must be created to the container. To create that SSH container, execute the following command:

$ cf ssh -N -T -L <LOCAL_PORT>:localhost:<REMOTE_PORT> <APPLICATION_NAME>

The REMOTE_PORT should match the port configuration for the application (8000 by default). The LOCAL_PORT can be any open port on your computer, but typically matches the REMOTE_PORT where possible.

Once the SSH tunnel has been created, your IDE should connect to localhost:<LOCAL_PORT> for debugging.

License

This buildpack is released under version 2.0 of the Apache License.