Kubernetes SD: Add node name and host IP to pod discovery

[jimmidyson]

Fixes #1604

/cc @pdbogen @fabxc

[fabxc]

This won't collide with any potential plans for pod live-migration or anything?

[jimmidyson]

Not that I can think of. Can you?

[fabxc]

I'm not involved enough to know whether there are such plans. But if live migration will become a thing the node label would change and no longer be static for the target.

[brian-brazil]

This is not the only thing that could potentially be dynamic among our SD mechanisms. As long as it being static is plausible then that's fine.

[jimmidyson]

All I can find with a quick search on pod migration is a really old issue (kubernetes/kubernetes#3949) that has had no progress. There are various other issues but in similar state & lining back to that issue.

[jimmidyson]

For now I expect it can be considered static.

[fabxc]

Okay, thanks 👍