Enable unexported-return linter rule

[ivanvc]

What would you like to be added?

There are two remaining linter rules that we haven't enabled but are left as TODO (./tools/.golangci.yaml): exported and unexported-return. The former will have significant changes to exported functions and interfaces. The latter, even though it impacts exported structs, it's for the better (it exposes them without breaking client implementations).

I suggest breaking the pull requests into small tasks like we did on #17578.

The following modules have warnings to be addressed:

• api - api: address revive unexported-return issues #18645
• pkg
• client/pkg
• client/v3
• server
• tests

Refer to the attached log file with the result from KEEP_GOING_MODULE=true make verify-lint.

Why is this needed?

To improve the quality of the code.

[ivanvc]

/assign @thedtripp

[k8s-ci-robot]

@ivanvc: GitHub didn't allow me to assign the following users: thedtripp.

Note that only etcd-io members with read permissions, repo collaborators and people who have commented on this issue/PR can be assigned. Additionally, issues/PRs can only have 10 assignees at the same time.
For more information please see the contributor guide

In response to this:

/assign @thedtripp

Instructions for interacting with me using PR comments are available here. If you have questions or suggestions related to my behavior, please file an issue against the kubernetes-sigs/prow repository.

[ivanvc]

@jmhbnz, could this be a bug? @thedtripp is already part of our org 🤔

Edit: I think it's because he doesn't belong to any teams. Should he open a pull request to add himself to the members? (https://github.com/kubernetes/org/blob/main/config/etcd-io/sig-etcd/teams.yaml#L77)

[thedtripp]

I'd like to work on this issue.

[thedtripp]

/assign @thedtripp

[jmhbnz]

@jmhbnz, could this be a bug? @thedtripp is already part of our org 🤔

Edit: I think it's because he doesn't belong to any teams. Should he open a pull request to add himself to the members? (https://github.com/kubernetes/org/blob/main/config/etcd-io/sig-etcd/teams.yaml#L77)

Good spotting - Yes this should be tidied up, @thedtripp please feel free to raise a kubernetes/org pr to add yourself to the members team 🙏🏻

[thedtripp]

@jmhbnz, could this be a bug? @thedtripp is already part of our org 🤔
Edit: I think it's because he doesn't belong to any teams. Should he open a pull request to add himself to the members? (https://github.com/kubernetes/org/blob/main/config/etcd-io/sig-etcd/teams.yaml#L77)

Good spotting - Yes this should be tidied up, @thedtripp please feel free to raise a kubernetes/org pr to add yourself to the members team 🙏🏻

I'll raise that PR in the next few days. Thanks!

[jmhbnz]

Discussed during sig-etcd triage meeting. There are a number of modules that need updating, so we could break this up into smaller chunks and do it one module at a team.

@thedtripp let us know which module you will focus on and we can assign out the others.

[ivanvc]

I'll do the first one (api) to set an example of what should be done with this issue.

[thedtripp]

@ivanvc @jmhbnz I'll take client/v3. Thanks!