Haha
you were a bit faster than me
I am also working on a Grafana module and am in the final steps (adding configuration ui, ...)
Nice work
Will try for sure!
[edit]: I just tried it. You took a different approach in using the render API and fetching on the icinga server. I implemented the module using the iframe embed method. This works better together with our SSO solution protecting Grafana. It also leads to graphs being zoomable etc.. well it's Grafana after all 
I couldn't get your module to work as we don't have the http auth enabled and can only use the Bearer header.
I like the configuration options, especially the per service configuration of the graphs.
What my module supports is different backends, currently influxdb and graphite. The only real change needed is that metrics need to be escaped for graphite.
You definitely, did some nice work! Hopefully I'm allowed to publish my module as well so we can learn from each other 