[Prometheus]: Improve Prometheus integration observability/debuggability #15693
Description
Integration Name
Prometheus [prometheus]
Dataset Name
No response
Integration Version
1.24.2
Agent Version
9.1.5
OS Version and Architecture
MacOS
User Goal
Improving observability of Prometheus Health.
- If Prometheus integration cannot connect to Prometheus with:
{"log.level":"error","@timestamp":"2025-10-20T12:00:51.996Z","message":"Error fetching data for metricset prometheus.collector: unable to decode response from prometheus endpoint: error making http request: Get \"http://localhost:9090/metrics\": dial tcp 127.0.0.1:9090: connect: connection refused","component":{"binary":"metricbeat","dataset":"elastic_agent.metricbeat","id":"prometheus/metrics-default","type":"prometheus/metrics"},"log":{"source":"prometheus/metrics-default"},"service.name":"metricbeat","id":"prometheus/metrics-prometheus.collector-7ad257bb-59ab-42e8-9ef3-7d93849a9318","ecs.version":"1.6.0","log.logger":"prometheus.collector","log.origin":{"file.line":335,"file.name":"module/wrapper.go","function":"github.com/elastic/beats/v7/metricbeat/mb/module.(*metricSetWrapper).handleFetchError"},"ecs.version":"1.6.0"}
The input reports configuring instead of degraded.
-
Queries sent to Prometheus should be logged in debug as at the moment there's no feedback anywhere.
-
We should log also in debug or info if a response from Prometheus query was empty.
Existing Features
At the moment we do not have a lot of feedback if a query is not returning data.
What did you see?
Only the succesful queries have traces in debug.
Anything else?
No response