The trace is basically extracted using Logstash's multiline filter. It adds a tag "stacktrace" to the log entry. I just made a few changes in SlackAlerter clas

The trace is basically extracted using Logstash's multiline filter. It adds a tag "stacktrace" to the log entry. I just made a few changes in SlackAlerter class to customize for my use-case. I'd try to clean-up and send a PR soon.