debug

How to debug an app

This how-to demonstrates how to debug a running application.

Java

To debug a Java application you have to set the BPL_DEBUG_ENABLED environment variable to true.
This is done with the epinio cli app env set command:

epinio app env set samplejava BPL_DEBUG_ENABLED true

After the application has restarted (to integrate the change of the environment) use port forwarding to attach the debugger. It runs by default on the port 8000:

epinio app port-forward sample 8000:8000

This will forward the traffic coming from localhost:8000 to the remote :8000.

Node

To debug a Node application you will have to start the application with the --inspect flag. Your package.json has to be similar to:

{
  "name": "nodejs-sample-app",
  "version": "1.0.0",
  "scripts": {
    "start": "node --inspect index.js"
  }
}

After the application has been deployed use port forwarding to attach the debugger. It runs by default on the port 9229:

epinio app port-forward sample 9229:9229

This will forward the traffic coming from localhost:9229 to the remote :9229.