Support custom metrics #676
Description
Background & X Problem
EaseProbe supports a series of health checking plugins, such as TCP, HTTP, MySQL etc. and even customized shell scripts, but all these plugins results predefined metrics. In some cases, it's expected to generate a customized metrics, e.g. the remaining days of a license.
Proposal and Expectation
Propose to add a embed a script engine, as a plugin, just like the Shell plugin, into EaseProbe, adding prometheus metric SDK. Then the user is able to write a script, registering metrics and reports metrics.
I didn't investigate and compare a lot but looks anko is convenient to achieve the goal.
Solutions & Y Problems
Of course it can be achieved by writing a prometheus exporter separately. but since a EaseProbe has been deployed on the node, it's expected to be done by an EaseProbe plugin. It's avoid to update configurations on the prometheus end.
Additional context
Add any other context or screenshots about the feature request here.