Add fluent-plugin-google-cloud as an official output plugin

[qingling128]

We'd like to submit a PR to add fluent-plugin-google-cloud as an official output plugin in this page.

This plugin is open sourced under Apache License 2.0 and is available on Github:
https://github.com/GoogleCloudPlatform/fluent-plugin-google-cloud.

Built gems are released to Rubygems at:
https://rubygems.org/gems/fluent-plugin-google-cloud.

The plugin is compatible with Fluentd 0.12 (Migrating to v1.0 is also on our roadmap).

Does this make sense? Any special requirements that we have to meet except following the doc site's convention/template? Wanna run some sanity check before starting to drafting the page.

[cosmo0920]

Official document pages describe td-agent bundled plugins.
fluent-plugin-google-cloud is not bundled for now.
And bundled plugin should use brand new v1(v0.14) API.

Should we handle this, @repeatedly ?

[qingling128]

@cosmo0920 - Thanks for the clarification! Right now we only support v0.12 and v0.14. The migration to v1.0 is on the road map in the near future. Bundling fluent-plugin-google-cloud into fluentd might require additional engineering work besides documentation. We would need to discuss this with Product and see what the priority is with that taken into consideration. Let's keep the conversation open though.

[repeatedly]

Hmm... relaxing the limitation is one idea.
GCP user is now increasing so adding its plugin article to docs.fluentd.org helps new users.
Of course, we are not a maintainer of google-cloud plugin so help is needed for managing the issue.

[qingling128]

Good to know that relaxing the limitation is an option. We will definitely be helping with drafting and maintaining the fluent-plugin-google-cloud doc through PRs.