Document GCP PodIdentity for PubSub

[hermanbanken]

Document PR kedacore/keda#2225 and issue kedacore/keda#2048.

Checklist

• Commits are signed with Developer Certificate of Origin (DCO)

Fixes issue kedacore/keda#2048

[hermanbanken]

DCO will be later... I didn't check the repo out locally yet.

[zroubalik]

Could you please update the docs in content/docs/2.5/scalers/gcp-pub-sub.md, the PR is opened against 2.4 version which has been already released and doesn't include the change. Thanks!

[tomkerkhove]

Added a few alignments with other scalers, would you mind taking a look at them please?

[hermanbanken]

@tomkerkhove in my opinion the interleaving of list items and (bold non-)titles and examples was confusing (see https://keda.sh/docs/2.4/scalers/gcp-pub-sub/ and https://keda.sh/docs/2.5/scalers/gcp-pub-sub/). That was why I opted for a list and then some examples. Due to the weird hierarchy people could overlook / fail to see that there are multiple authentication options.

However, maybe the sentence There are three options to configure authentication: is clear enough already.

[tomkerkhove]

see keda.sh/docs/2.4/scalers/gcp-pub-sub

I'm not sure I get what you are referring to here, sorry?

@tomkerkhove in my opinion the interleaving of list items and (bold non-)titles and examples was confusing.
[...]
That was why I opted for a list and then some examples. Due to the weird hierarchy people could overlook / fail to see that there are multiple authentication options.

Unfortunately it's more about documentation consistency - If we change this then we should update all other scalers to be aligned; otherwise it will be very hard to maintain/use KEDA.

I hope that sounds reasonable to you?

So I'd suggest to align it with other scalers and open an issue to propose a change that is aligned across all scalers. Make sense?

[hermanbanken]

I'm mostly complaining about the fact that the title size of the examples breaks the iteration of the different authentication parameters. I understand the consistency remark, but I do not have the time to update all existing documentation (sorry!).

Maybe There are three options to configure authentication: is a good enough heads-up that there will follow 3 different options, regardless of the messed up outline.

[tomkerkhove]

I understand the consistency remark, but I do not have the time to update all existing documentation (sorry!).

I'm definitely not asking for that :D

Maybe There are three options to configure authentication: is a good enough heads-up that there will follow 3 different options, regardless of the messed up outline.

It's not the intent to have the samples before the other auth mechanisms though. Here is an example: https://keda.sh/docs/2.4/scalers/aws-sqs/#authentication-parameters

[zroubalik]

@tomkerkhove @hermanbanken what is the status of this issue? It is one of the lastest ones for our upcoming release.

[tomkerkhove]

@hermanbanken Do you have time to complete this PR or prefer if I complete it?

[hermanbanken]

@tomkerkhove I've updated it to mostly comply with the AWS variant. If you think further changes are needed please feel free to make them (I wont be available the rest of the day).

[tomkerkhove]

LGTM, merging in temp branch to fix DCO