Allow "scrape_uri" to be passed via URL as target about apache_exporter

[schweikert]

I will try to write a patch for this :)

[Lusitaniae]

I wouldn't say is an anti pattern because one exporter does that, while every other one does not.
If you have more examples would be interesting to hear about it.

prometheus/haproxy_exporter#65 (comment)

You can see this comment here, grobie is using chef to setup Haproxy and the respective exporters and record the results in consul for service discovery.
Prometheus will then query consul to know what exporters to scrape.

Therefore, keeping the rule of one exporter per process being monitored.

[schweikert]

You are probably right that it isn't necessarily considered an anti-pattern.

Still, it would be nice (and easy I think) if it could work both ways. If a target is specified, use that, otherwise take what is configured on the command-line (or the default).

This would make deployment in many cases much easier.

[Lusitaniae]

If you read this page, the blackbox and snmp exporter are particularly singled out as being exceptions to one process one exporter rule: https://prometheus.io/docs/instrumenting/writing_exporters/.

There are two exceptions:

The first is where running beside the application your monitoring is completely nonsensical. The SNMP, blackbox and IPMI exporters are the main examples of this.

. For exporters such as the blackbox exporter and SMNP exporter, which aren’t tied to a single target, these should only be exposed on a vanilla /metrics call, not on a scrape of a particular target.

Allowing prometheus to scrape multiple targets from a single exporter would be the anti-pattern.

I think its not worthwhile to come up with a patch. I try to keep the exporter as closely as possible to the official exporters, and the ones more closely related to Apache exporter don't support that option.

Better spend the extra time working on the deployment.

[schweikert]

OK, I won't spend time in creating a pull request. Personally I still think that it would be a small change with no big maintenance burden that could be useful to some users.