Error 502 Bad Gateway

[schpvs92]

Hey guys,

i got the following issue:
using Grafana v11.2.0 (c57667e448)
grafana-checkmk-datasource 3.3.0
and
checkmk RAW 2.2.0p9

Im getting the error 502 Bad Gateway when im trying to test the grafana-checkmk-datasource connection to my checkmk instance.
The Firewall isnt blocking, grafana is running in a docker.

Does anyone have any idea what might be the issue?

[BenediktSeidl]

Can you check if you can reach your Checkmk instance from inside the Grafana docker container?
The 502 Bad Gateway should be visible in your Grafana logs. What error message do they show exactly?

[schpvs92]

@BenediktSeidl hey. thanks for the fast answer.

Pinging from docker works fine. Im also able to see the requests in our firewall.
Actually by using
docker logs grafana i found the following error:
level=error msg="Proxy request failed" err="tls: failed to verify certificate: x509: cannot validate certificate for "IP of our checkmk server" because it doesn't contain any IP SANs"

[BenediktSeidl]

So you are using a self-signed certificate, but Grafana or the docker container does not trust the CA? Or something similar?

[schpvs92]

Yes, it seems like grafana is not trusting the CA. To check that, is it possible to disable that security mechanism?

[BenediktSeidl]

I don't know, this is independent of the checkmk data source, we just use the Grafana API for this.

But you can use something like https://mitmproxy.org/ and use a http:// URL for the data source instead of a https:// one.