Add descriptor visibility filter

[jetersen]

No description provided.

[pjdarton]

My concern with these is that the visibility filter is saying "These must not be shown to anyone" whereas the truth is that they should be an option for vSphere cloud-provisioned slaves (but only vSphere cloud-provisioned slave nodes).
I suspect that the @CheckForNull Object context argument is intended to be used to allow visbility filters to say "we're only visible to vSphere cloud-provisioned slave nodes".

...that said, I think this would only ever become a problem if vSphereCloudSlaveTemplate.DescriptorImpl.getRetentionStrategyDescriptors() was re-coded to ask Jenkins to list all appropriate retention strategies instead of hard-coding that list tho' ... so we can get away with this simple implementation for now 😁

If you agree with that, and you're happy for this to be merged, please add a PR description and I'll merge it.

[pjdarton]

I suspect an end-of-line issue - the diff is now showing you've replaced the entire contents of both files...

[jetersen]

😱 I just used GitHub to merge a simple conflict 😭

[pjdarton]

Of course, fixing the EOLs in #114 has meant this now has merge issues ... again 😀

[jetersen]

i'll double check on the visibility but I recall them as being visible and selectable :)

[pjdarton]

Thank you for your perseverance 👍

[pjdarton]

PS. It's the end of my working day now, but if you find any other issues, comment/raise-a-PR etc and I'll be back online in around 15 hours.

[jetersen]

Just tested with the latest incremental build from master. Visibility filter works just fine:

This is a cloud provisioned one 😄

[pjdarton]

For a cloud-provisioned slave, none of that should be editable anyway... They should be edited by configuring the template that defines how they're created, but that's (probably) a bug unrelated to your changes - one of many minor bits of tech-debt in this plugin code.

The important things are that:

1. When creating or editing a (vSphere slave) template, the vSphere retention strategies are available to be selected. I think that code has a hard-coded list of just the two vSphere options and doesn't pay any attention to visibility filters, so that should be unaffected.
2. When creating a new non-cloud vSphere slave, the vSphere retention strategies are available to be selected.
3. When creating any other kind of slave, the vSphere retention strategies are not available.
4. When editing a previously-created slave, the same retention strategies are listed as were available when it was created.