Integration tests for prometheus.exporter.snmp

[ptodev]

Request

It would be good to have SNMP integration tests in internal/cmd/integration-tests/tests/. The test would start an SNMP simulator, and check if metrics are received by Mimir. This is similar to other tests that we have like the Redis one.

There are also public SNMP endpoints which could be used for manual testing, but it wouldn't be a good practice to use them in a CI. For example, this config calls a public endpoint:

prometheus.exporter.snmp "snmp_metrics" {
  target "testing1" {
    address = "demo.pysnmp.com"
    module = "if_mib"
    auth = "public_v2"
  }
}

prometheus.scrape "snmp_metrics" {
  targets    = prometheus.exporter.snmp.snmp_metrics.targets
  forward_to = [prometheus.remote_write.snmp_metrics.receiver]
  scrape_interval = "5s"
  scrape_timeout = "500ms"
}

prometheus.remote_write "snmp_metrics" {
  ...
}

The config for prometheus.exporter.snmp could be as simple as possible. The main goal of this issue is to bootstrap the test framework. The simulator is in Python and AFAIK it doesn't come in Docker containers, so I'm not sure how we will run it in the Alloy CI.

Use case

Improving the test coverage :)