Grafana Integration

[dwffls]

Draft PR based on #401
Creating a new node that can export all diagnostics to telegraf or influxdb to be used with tools like grafana.

[dwffls]

Build doesn't complete as it misses the dependency to cURL, @ct2034 could you help me with this?

[dwffls]

Yup that fixes it

[ct2034]

Thanks for your work. This looks very good.
I think a big part that is currently missing is tests. What is your plan for them? I am not sure if spinning up an actual grafana instance may be overkill, but maybe you can mock the receiving interface.

[dwffls]

I've added unit tests for the conversion from diagnostic_msgs to the Influx-compatible line protocol. This is the primary focus of the package and, in my opinion, the area most prone to potential errors.

The remaining code consists of a lightweight node that connects to an InfluxDB or Telegraf instance using basic curl functions. I'm uncertain how to effectively test this part, as errors are more likely to originate from changes on the other side of the connection. As such, I'm questioning whether adding tests here would provide significant value.

[ct2034]

Please change

[dwffls]

You mean the year right? Or also the copyright holder? If so what should that be?
This is the first time i've done anything like this

[ct2034]

And please add your package to [.github/workflows/lint.yaml] and [.github/workflows/test.yaml]