There's the default HTTP provider that's included in puppet core now for the puppet-dashboard. I think foreman should use this HTTP report to eliminate code duplication.

https://github.com/puppetlabs/puppet/blob/master/lib/puppet/reports/http.rb

Looks like the difference between the report parsers, foreman accepts the YAML in a report variable, whereas the dashboard uses request.raw_post. To get it working in my environment, I changed line 34 in reports_controller.rb from:

if Report.import params.delete("report")

to

if Report.import (params[:report].nil? ? request.raw_post : params[:report])