Thanos Sidecar Exposure and Scraping

Expose the Thanos Sidecar's HTTP metrics and gRPC StoreAPI interfaces via a dedicated service. ClusterIP is set to none to allow for full discovery of all endpoints behind the service via in-cluster DNS. This allows for a new ServiceMonitor to then scrape the metrics available on the Sidecar's HTTP port.

A new service has been used so as to separate out the metrics that Prometheus makes available, and the metrics the Thanos Sidecar makes available. The Thanos Mixins from thanos-io/thanos default to a job label of 'thanos-sidecar', and hence the service here has had this label applied.