chore: using go-kit fields plus minor improvements

[fracasula]

Changes

• labels for go now use the go-kit type which allows for both sugared and non-sugared logging
• split main.go to always close files on error
• renamed team to domain
  • domain is more specific and a single team can have multiple domains (e.g. there is no warehouse team, there is the pipelines team with warehouse domain)
• adding some helper functions to the go template
  • the goal here is to jump less from the template file to types.go. ideally we want to be able to understand the majority of what is going on just by looking at the template file and then leave only functions that are too complex for a template to types.go

Related PRs

For a showcase about how this can be used check the Pull Requests below:

• rudder-go-kit
• rudder-server

[koladilip]

Looks good, I am thinking rudder-go-kit should depend on obs-kit, should we move the functionality related to observability to obs kit?

[lvrach]

Shall we introduce a github action ensuring the generators have been executed, something like this

[lvrach]

was this removed intentionally?

[fracasula]

Yes, the old name[T] was replaced with the gokit/logger.Field.
If you're referring to UploadTime, I want to tackle the fields that we'll need in separate PRs. Here we're just putting down some ground work then we can do a dedicated PR where we just add stuff to the labels.yaml file and generate.

[lvrach]

[non-blocking] Should we introduce a prefix for domain-specific metrics ? or maybe put them in a different package ?

[fracasula]

We thought about it but avoided it to cause a conflict on purpose to make people rethink the label name. Perhaps if it's a conflict it might be a duplicate. If it's not a duplicate then a prefix can be added manually by changing the label name itself (i.e. by making the label name more verbose/explanatory for example).

[fracasula]

Shall we introduce a github action ensuring the generators have been executed, something like this

@lvrach Done. I pushed a label without generating and the CI broke here: https://github.com/rudderlabs/rudder-observability-kit/actions/runs/6879882237/job/18712820643?pr=5

[fracasula]

@lvrach @koladilip I added also linters and checkers that linting, go mod tidy and formatting are done properly along with tests running on CI.

Since you both approved I'm going to merge as soon as I have a rudder-go-kit version even if the approvals got dismissed (we'll change the setting later).

[fracasula]

DO NOT MERGE: we need a stable version of the go-kit first. Please review: rudderlabs/rudder-go-kit#202