Grafana datasource connection problems (only while accessing Grafana from internet)

[danielpa]

Hello friends,

following situation:

We use Check_MK version 2.0.0p1 and Grafana version 7.4.2. The most recent Checkmk datasource plugin is installed.

Our Grafana is running in the DMZ and can be accessed either from intranet as well as from internet, using the same domain ( https://grafana.ourdomain.tld ). The Check_MK URL that is configured inside the datasource plugin is a local host and can only be accessed from the intranet ( https://checkmk.mydc.local ).
Now, if I access Grafana form the intranet, everything works as expected, Check_MK data is shown properly.
If I access Grafana from the internet, the Grafana datasource plugin throws me an error if I test the connection:

Could not read API response, make sure the URL you provided is correct.

And ofcourse, the dashboards stay empty.

What’s the actual problem here? Why does it work from the intranet but not from the internet?
Is it because the Check_MK URL is only accessbile from the intranet? I was sure that only Grafana needs to be able to access Check_MK, and not the end user. Was I wrong? Any further suggestions?

Regards

[r.sander (Robert Sander)]

The Grafana datasource is using the browser to connect to the checkmk site. It has to be reachable.

[danielpa]

Ok, thanks for the information. This is kind of unfortunate, because I would rather avoid putting my checkmk instance into the DMZ.

[Josef]

Ok we had the same problem, I thought the Grafana-Server fetches the data from the CMK-Server but if the client/browser itself needs a connection to the CMK-Server ist kind of sad.