MinIO Using Non-standard Prometheus Path to Check Availability for Console Metrics

[jem-Solytica]

When using Mimir to aggregate and scale Prometheus metrics, MinIO fails to display Prometheus metrics.

This may be related to a pre-check that MinIO conducts prior to requesting metrics, based on this issue minio/minio#17996

Expected Behavior

If MinIO does a Prometheus pre-check before querying metrics, it should call a known URL or a URL that doesn't depend on the user running Prometheus Server

Current Behavior

When checking for metrics in the console, receive an unavailability error with respect to prometheus URL, even though I'm able to query similar metrics in Grafana.

Possible Solution

The Mimir team provided an alternate URL/path that can be called to pre-check if Mimir/Prometheus is available: grafana/mimir#7399

Steps to Reproduce (for bugs)

1. Install and Configure Mimir
2. Confirm Mimir works (e.g., by configuring as a datasource in Grafana or directly querying using cURL)
3. Set MINIO_PROMETHEUS_URL to Mimir URL (including /prometheus as part of the URL)
4. Restart MinIO
5. Check for metrics in MinIO console

Context

I have to rebuild dashboards in Grafana or elsewhere and cannot track everything in the console.
 

Regression

Your Environment

• Version used (minio --version):
• Server setup and configuration:
• Operating System and version (uname -a):

• MinIO via Docker (latest) on Ubuntu 22.04, AMD64
• Prometheus/Mimir running on same /24 LAN subnet

[harshavardhana]

@jem-Solytica we have never mentioned that we support mimir however this is a valid thing we can support a lot of clones like this.

curl -v 'http://mimir/prometheus/api/v1/query?query=vector(0)'

We can simply do this @dvaldivia