This was previously reported as #127
There is currently no way to pass several fields present in the PagerDuty Common Event Format (PD-CEF), most notably Severity, Component, Group, and Class. These fields are potentially very useful in certain deployment strategies, so it would be ideal to see them supported.
I'm resubmitting because we still need this to be solved. We have tried the suggestion of switching to go-pdagent but it has other bugs and we gave up after many days of effort trying to make it work for our situation.
See my comment for more context related to PagerDuty support of the integration (which extends beyond the scope of this bug)