Add POD_NAME environment variable for the Spilo Pod

[bleleve]

Hello everyone,

As part of our cluster deployment we need the POD_NAME environment variable which is initialized on the sidecar but not on the Spilo pod. This envvar may be useful to others.

Best regards.

[FxKu]

Have nothing against the change so thanks @bleleve for contributing. But it would trigger a rolling update of all your clusters. This is similar to e.g. the change proposed in #1577. I think, I would incl. both in the next 1.8.0 release with a proper statement in the release notes.

[FxKu]

It looks like #1794 could solve your problem, too. Maybe we can close this one then?