Prometheus metrics

[paurosello]

Description

Current operator and the webhook does not expose any kind of metrics. We need to expose prometheus metrics from both components.

Proposal

Operator metrics for each object:

• Organizations
• Tenants (with organization tag)
• Spaces (with organization and tenant tag)

We should collect metrics about:

• Count
• Memory
• CPU

Webhook metrics:

• Number or requests
• Failed requests
• Requests process time

Before

$ curl http://k8spin-operator:12345/metrics
404

$ curl http://k8spin-operator-webhook:12345/metrics
404

After

$ curl http://k8spin-operator:12345/metrics
200

$ curl http://k8spin-operator-webhook:12345/metrics
200

Expected output

All the metrics should be documented to being able to use it in (for example) a grafana Dashboard