400 Bad Request - There Was An Error Returned Querying The Prometheus Api [BEST]

Prometheus expects a Content-Type header for POST queries ( application/x-www-form-urlencoded ). If the proxy manipulates this, Prometheus throws a 400.

Troubleshooting the Ghost: Decoding the “400 Bad Request” from the Prometheus API Prometheus expects a Content-Type header for POST queries

If you request 6 months of data at 1-second resolution, you are asking Prometheus to scan billions of samples. The server may reject the query immediately with a 400 because it recognizes the resource cost is impossible. Prometheus expects a Content-Type header for POST queries