Metric label values truncated when using OpenMetrics endpoint

[Josef 'Jeff' Sipek]

On Tue, Aug 25, 2020 at 01:08:06 +0000, Daan van Gorkum wrote:
> Hi Jeff,
> 
> Thanks for your reply!
> 
> Regarding grouping by remote address, I understand and for now I'll keep a
> close eye. Maybe it's an option to group by /24 for ipv4 and /64 for IPv6?

Hrm, interesting idea.  But the answer is: no, there isn't a way.  The
simplest way to implement something like this would be to add a new
aggregating function.  So one could do something like:

	remote_ip:netmask4:24
	remote_ip:netmask6:64

To get /24 and /64, respectively.

I'll throw this idea on the ever growing pile of things that can be worked
on :)  Obviously, I can't make any promisses about this ever getting done.

> We currently do that based on the logs but the OpenMetrics endpoint seem a
> lot easier.

Aggregating based on a subnet definitely makes sense.

> A slight hijack of the original question: but I tried to log only IP
> addresses (+ result) of failed login attempts but it seems I cannot find a
> metric that would contain that information. Am I looking in the wrong
> direction? The auth_userdb_request_finished and
> auth_passdb_request_finished stats work as intended but they do not
> contain any information about the connecting client.

I haven't played with these events, but at least based on the docs [1],
auth_client_userdb_lookup_finished and auth_client_passdb_lookup_finished
events seem to have the remote_ip field as well as an error string on
failure.  Does that give you the info you need?

Jeff.

[1] https://doc.dovecot.org/admin_manual/list_of_events/