[pkg/ottl] Add a new ottl function Keys

[jaysonsantos]

Description

This adds a new ottl function called Keys

The idea here is because, I have a use case to debug traces being sent to newrelic where some spans are being dropped because of the attribute's names (and they don't specify which). The final idea is to be able to filter out attributes that are bigger than the threshold specified by them and send to a log or something.
A next step would be some sort of filter function like Filter(Keys(resource.attributes), Len(key) > 100)

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An ugly implementation of the fiter can be seen here main...jaysonsantos:opentelemetry-collector-contrib:ottl-add-filter-function

[github-actions]

This PR was marked stale due to lack of activity. It will be closed in 14 days.

[edmocosta]

Thank you for you contribution, @jaysonsantos. I've left a few comments for your consideration. We also gonna need a change log for this PR.

[jaysonsantos]

@edmocosta i did the requested changed, just left two other questions.
Also, should I rebase with main now or wait until you are done with the review?

[edmocosta]

Also, should I rebase with main now or wait until you are done with the review?

Please rebase, so we can trigger the CI. Thanks!

[github-actions]

This PR was marked stale due to lack of activity. It will be closed in 14 days.

[github-actions]

Closed as inactive. Feel free to reopen if this PR is still being worked on.

[jaysonsantos]

@atoulme the changes were addressed but the ci timed out

[edmocosta]

Hi @jaysonsantos, could you please add a change log for this function: https://github.com/open-telemetry/opentelemetry-collector-contrib/blob/main/CONTRIBUTING.md#adding-a-changelog-entry?

[jaysonsantos]

@edmocosta done

[jaysonsantos]

@edmocosta i have another branch with the function values, should i get the learnings from this, apply, and tag you or let the system choose?

[edmocosta]

@edmocosta i have another branch with the function values, should i get the learnings from this, apply, and tag you or let the system choose?

Hi @jaysonsantos, we normally prefer to discuss new functions/converters through issues, it ensures the function is aligned with OTTL requirements/guidelines, and also avoid folks spending their time writing code that might not get accepted at the end. That said, ideally, raising an issue would be the next step for that values function you're proposing :)

[jaysonsantos]

hi @edmocosta the label says it depends on me but. think it is all set, right?

[edmocosta]

hi @edmocosta the label says it depends on me but. think it is all set, right?

I'm sorry, I forgot to remove the label. @evan-bradley @TylerHelmuth could you please take a look at this? Thanks!