fix getRegionFromZone(), add exporter_test.go

[jjo]

Changes overview:

• exporter.go:
  • Fix getRegionFromZone(), also make other functions use <provider>.ProviderName recently added (instead of fixed strings)
• exporter_test.go:
  • Add test coverage to some functions, including the one fixed above
• Dockerfile:
  • add --load to Dockerfile to support buildx setups.

--
Signed-off-by: JuanJo Ciarlante [email protected]

[inkel]

LGTM! I just left some Go-style related comments but nothing that needs change; just left it there to:

• spread the knowledge;
• cannot help myself.

[paulajulve]

We tested the changes to the makefile on my machine too, and it seems to be compatible with my docker setup too.

[jjo]

About to merge, built and verified running ok (and scraping :8080/metrics with:

# AWS
docker run -v $HOME/.aws:/root/.aws:ro -p 8080:8080 us.gcr.io/kubernetes-dev/unused:v0.0.3-78-g96944e9 --aws.profile some-profile --aws.providername=EKS

# GCP
docker run -v $HOME/.config/gcloud:/root/.config/gcloud:ro -p 8080:8080 us.gcr.io/kubernetes-dev/unused:v0.0.3-78-g96944e9 --gcp.project some-project --gcp.providername=gke

[jjo]

built from main and pushed to us.gcr.io/kubernetes-dev/unused us.gcr.io/kubernetes-dev/unused:v0.0.3-79-gc2eb1aa