chore: Fix linter findings for revive:exported in plugins/inputs/[a-b]*

[zak-pawel]

Summary

Address findings for revive:exported in plugins/inputs/[a-b]*.

As part of this effort for files from plugins/inputs/[a-b]*, the following actions were taken:

• Type names (const, var, struct, func, etc) were changed to unexported, wherever they didn't need to be exported.
• All remaining exported types were given comments in the appropriate form – this does not apply to exported methods that implement "known" plugin interfaces (Gather|Init|Start|Stop|SampleConfig|Parse|Add|Apply|Serialize|SerializeBatch|SetParser).
• The order of methods was organized (exported methods first, then unexported, with init at the very end).

It is only part of the bigger job (for issue: #15813).
After all findings of this type in whole project are handled, we can enable revive:exported rule in golangci-lint.

Checklist

• No AI generated code was used in this PR

[srebhan]

Thanks for your effort @zak-pawel! I do have some comments with the most sever being to remove the useless comments! :-)

[zak-pawel]

I do have some comments with the most sever being to remove the useless comments! :-)

@srebhan
The thing is, the exported rule is designed to detect uncommented "things" of the exported type. And while we can filter out methods with known names, it will be hard for us to do that for several hundred plugins and their public structs.

The options I see are:

1. Grit our teeth and put a comment like // StructureName over every public structure (representing a certain plugin) everywhere (we don't need anything more).
2. As above, but put //nolint xD
3. Did you know that these structs don't have to be exported? We can make them unexported... Only their fields need to be exported.
4. We can take the same steps I took in this PR for the entire codebase (except for the structs we're talking about), but not enable the exported rule.

Point 2 seems very poor.
Similarly, point 4 - because I see value in this rule - it will make it easier for us to review new code, in which we often overlook that there are types that could be unexported.

[srebhan]

@zak-pawel how about adding a config option to the linter? :-)

[zak-pawel]

@zak-pawel how about adding a config option to the linter? :-)

@srebhan To disable checking whether comments exist on the exported structs?

[srebhan]

Yes. We just need a PR on revive for that. :-P

[zak-pawel]

Yes. We just need a PR on revive for that. :-P

@srebhan Such PR already exists: mgechev/revive#1047

[telegraf-tiger]

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Artifact URLs

DEB	RPM	TAR GZ	ZIP
amd64.deb	aarch64.rpm	darwin_amd64.tar.gz	windows_amd64.zip
arm64.deb	armel.rpm	darwin_arm64.tar.gz	windows_arm64.zip
armel.deb	armv6hl.rpm	freebsd_amd64.tar.gz	windows_i386.zip
armhf.deb	i386.rpm	freebsd_armv7.tar.gz
i386.deb	ppc64le.rpm	freebsd_i386.tar.gz
mips.deb	riscv64.rpm	linux_amd64.tar.gz
mipsel.deb	s390x.rpm	linux_arm64.tar.gz
ppc64el.deb	x86_64.rpm	linux_armel.tar.gz
riscv64.deb		linux_armhf.tar.gz
s390x.deb		linux_i386.tar.gz
		linux_mips.tar.gz
		linux_mipsel.tar.gz
		linux_ppc64le.tar.gz
		linux_riscv64.tar.gz
		linux_s390x.tar.gz

[srebhan]

Nice, just one comment regarding the toml-option naming.

[srebhan]

Thanks @zak-pawel!