Line data    Source code

       1              : use axum::{body::Body, response::Response};
       2              : use http::header::CONTENT_TYPE;
       3              : use http::StatusCode;
       4              : use metrics::proto::MetricFamily;
       5              : use metrics::Encoder;
       6              : use metrics::TextEncoder;
       7              : 
       8              : use crate::{http::JsonResponse, installed_extensions};
       9              : 
      10              : /// Expose Prometheus metrics.
      11            0 : pub(in crate::http) async fn get_metrics() -> Response {
      12            0 :     // When we call TextEncoder::encode() below, it will immediately return an
      13            0 :     // error if a metric family has no metrics, so we need to preemptively
      14            0 :     // filter out metric families with no metrics.
      15            0 :     let metrics = installed_extensions::collect()
      16            0 :         .into_iter()
      17            0 :         .filter(|m| !m.get_metric().is_empty())
      18            0 :         .collect::<Vec<MetricFamily>>();
      19            0 : 
      20            0 :     let encoder = TextEncoder::new();
      21            0 :     let mut buffer = vec![];
      22              : 
      23            0 :     if let Err(e) = encoder.encode(&metrics, &mut buffer) {
      24            0 :         return JsonResponse::error(StatusCode::INTERNAL_SERVER_ERROR, e);
      25            0 :     }
      26            0 : 
      27            0 :     Response::builder()
      28            0 :         .status(StatusCode::OK)
      29            0 :         .header(CONTENT_TYPE, encoder.format_type())
      30            0 :         .body(Body::from(buffer))
      31            0 :         .unwrap()
      32            0 : }