A user reached me to add a way to add the custom labels into the statsd module, so a better way to report metrics to the observability platform.

I keep the same old functions and add a new parameter to the statsd modules to both interfaces cfg and kemi.

The full documentation can be found here: https://docs.datadoghq.com/developers/dogstatsd/datagram_shell/?tab=metrics

So, each function can be used like this: ``` statsd_set("fooo", 1, "inbound"); statsd_gauge("NotFound", "+1", "outbound,carrierFoo"); statsd_gauge("AuthFailed", "+1", "carrier=foo,priority=10"); ```

Signed-off-by: Eloy Coto <eloy.coto@acalustra.com> Tested-by: Alex Antonevych <alex.antonevych@replicant.ai>

<!-- Kamailio Pull Request Template -->

#### Pre-Submission Checklist - [x] Commit message has the format required by CONTRIBUTING guide - [x] Commits are split per component (core, individual modules, libs, utils, ...) - [x] Each component has a single commit (if not, squash them into one commit) - [x] No commits to README files for modules (changes must be done to docbook files in `doc/` subfolder, the README file is autogenerated)

#### Type Of Change - [ ] Small bug fix (non-breaking change which fixes an issue) - [x] New feature (non-breaking change which adds new functionality) - [ ] Breaking change (fix or feature that would change existing functionality)

#### Checklist: - [ ] PR should be backported to stable branches - [x] Tested changes locally

I'm waiting until first review on function arguments to create the docs changes.

You can view, comment on, or merge this pull request online at:

https://github.com/kamailio/kamailio/pull/3529

-- Commit Summary --

* statsd: Add labels to metrics.

-- File Changes --

M src/modules/statsd/lib_statsd.c (102) M src/modules/statsd/lib_statsd.h (10) M src/modules/statsd/statsd.c (129)

-- Patch Links --

https://github.com/kamailio/kamailio/pull/3529.patch https://github.com/kamailio/kamailio/pull/3529.diff