Prometheus web path is enabled in the ingress while not properly configured

[sayf-eddine-scality]

Component:
monitoring

What happened:
prometheus endpoint is available under /api/prometheus and the web component is not deactivated. This will result in an ugly broken page at /api/prometheus/graph

What was expected:
either a 404 or a working graph page

Steps to reproduce
navigate to /api/prometheus/graph

Resolution proposal (optional):
two solutions:

• Disable the web component (aka no more prometheus/(graph/targets/status) )
• Keep the web component without documenting it (for dev/test purposes) but tell prometheus where it is hosted so it serves the page correctly using --web.external-url