Automate update of KEDA version in the code and yaml files during each release

[zroubalik]

Expected Behavior

We should update a version in https://github.com/kedacore/keda/blob/master/version/version.go during each release. It is set to 1.0.0 currently, which is wrong. This value is printed in logs during the operator startup/run.
Same for the versions in the yaml files under deploy directory

This should be automated

Actual Behavior

Not updated

[tomkerkhove]

That would be a new first step in https://github.com/kedacore/keda/blob/master/RELEASE-PROCESS.MD, is that right?

[zroubalik]

Yes, but I'd like to see it automated. I am not that much familiar with GitHub workflows, so not sure if that's possible. But it is a matter of very simple bash script and regex.

[zroubalik]

@ahmelsayed might know it better

[Cottonglow]

The Makefile in #596 will replace the version in version.go but the PR also introduces more files that need to be substituted.

The deploy yaml files will include a version label which currently would need to be updated manually before each release.

I have found a few ways of getting this to potentially work - although unsure whether they are too hacky:

1. Run a script to sed the version before creating a release
2. Update the Makefile to sed the yaml files and output the new files into a build/deploy folder

The 2nd one would mean people need to go into the build/deploy directory to get the new scripts instead of the deploy directory currently.
Unless we have a template/deploy folder with the yaml files, copy those files to the deploy folder (to prevent updating files in 2 places) and do the variable substitution with sed.

[zroubalik]

@Cottonglow I think that a new target, like make release or make prepare-release or something like that would be great.

It would change the versions in version.go and yaml files (both the app.kubernetes.io/version: and image reference). So then it could be the first step in the release process.

[Cottonglow]

I've created the above PR which contains a new target release. I gave it a dry run on my side and it seems to work. Would be happy for someone else to test it as well just in case.