Error reading Prometheus: Post "/api/v1/query": unsupported protocol scheme ""

Grafana Prometheus
1

I got following message when I tried to save the Prometheus data source

Error reading Prometheus: Post “/api/v1/query”: unsupported protocol scheme “”

grafana-enterprise-8.3.3.linux
prometheus-2.32.1.linux

2

same exact error… both grafana and prometheus installed on a lxc, using ubuntu 21 container. I am able to save the default data source, but the error “Error reading Prometheus: Post “/api/v1/query”: unsupported protocol scheme “”” is always there at the bottom of the screen - either during data source save or when trying to run any query in explorer…

prometheus, version 2.32.1, grafana * v8.3.3 (30bb7a93ca)
Ubuntu 21.04, proxmox container.

EDIT: I can repro the same scenario when running from a ubuntu20 VM, so does not seem to be container-related…

3

I just encountered this… I saw that the Prometheus URL was pre-filled with the correct value. HOWEVER, I had to actually type in the same URL as the default (http://localhost:9090) for it to work.
Hope that helps.

1 Like
4

confirmed on my end - typing the default value http://localhost:9090 instead of keeping it default - works! Thanks!

5

It’s because of missing the protocol. Adding “http://” protocol in front of the .… in the URL field solved the problem.

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