A simple service to watch Kubernetes Prometheus custom resource instances and write the gathered targets to a service discovery file for the Thanos querier.

This service currently has a very simple, rudimentary implementation. It lists all services in its Kubernetes cluster that contain a specific label key-value pairing (operated-prometheus=true), which is set by the Prometheus operator. From each service it builds a DNSSRV record and adds that to a target list to be written out as a YAML file for ingestion by a Thanos Querier. This service will then wait for a specified interval, after which it will relist and rewrite the file.

The intended use case here is to run this as a sidecar container that writes out the result file to a shared volume with a Thanos Querier configured to read additional targets from the shared volume.

At present there are only two CLI flags that can be set: the wait interval duration, and the output file location.