fix: General err handling for collector

[jneo8]

The error handler will try to output the failed metrics and make sure the single collector's bug won't affect other collectors.

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Review together with: canonical/hardware-observer-operator#117

[chanchiwai-ray]

Ideally, the collector itself should be responsible to catch general error, and produce a payload when it is failed.

This changes might potentially affect all collectors, can you add functional test? i.e. enable a collector, mock the fetch function to raise exception, and see if it outputs the failed metrics?

Or at least test it manually

[jneo8]

Ideally, the collector itself should be responsible to catch general error, and produce a payload when it is failed.
This changes might potentially affect all collectors, can you add functional test? i.e. enable a collector, mock the fetch function to raise exception, and see if it outputs the failed metrics?
Or at least test it manually

Yes, unit test and manually test are done.

Agree with your point that collector should responsible to catch it's error. But won't it be the same if we need to have this practice on all the collectors?
Instead of catch general error on each collector, reduce the possible to make human error, like every time you create a new collector and you need to remember this practice, adding catch in core module maybe make more effectually and safe from my point of view.

[Pjack]

Request to update the test plan and test case.

[dashmage]

A few typos to fix. Otherwise LGTM :)

[rgildein]

LGTM thanks

[jneo8]

Waiting for canonical/hardware-observer-operator#117