Expose GCE labels during service discovery

[woolite64]

Proposal

Expose GCE instance labels as __meta_gce_label_ so that values can be passed to Target Labels.

It's currently possible to filter by GCE labels using Prometheus, but the values aren't available once the host is found. Tags and metadata are exposed (here) with __meta prefixes.

[brian-brazil]

Would you like to send a PR? We generally accept all potentially useful metadata.

[woolite64]

Open to creating a PR, but having some dependency issues.

My local vendor files don't have the Instance.Labels parameter in the docs. It looks like the Google Compute dependencies that get imported don't match the docs here: https://godoc.org/google.golang.org/api/compute/v1

[brian-brazil]

It sounds like you'll need to update the vendoring. We use govendor for this,

[woolite64]

Opened a PR for this. First time using Go, any feedback is appreciated.

I was able to compile, run tests, and confirm that GCE labels were working on my end.

[lock]

This thread has been automatically locked since there has not been any recent activity after it was closed. Please open a new issue for related bugs.