We have exactly that for a sidecar on one of our team’s k8s clusters. There is a legacy python 2.6 twisted service. It will not get priority to be updated (func

We have exactly that for a sidecar on one of our team’s k8s clusters. There is a legacy python 2.6 twisted service. It will not get priority to be updated (functionality is being slowly eroded into other services). It exposes its metrics in a non-standard way and updating it to emit to Prometheus was going to be non-trivial. Enter the sidecar. It lives next to each instance and scrapes the metrics and converts them over for Prometheus to consume, and happens to be written in Go. It was developed and released in a day or two.