camel_prometheus/
server.rs

1use std::net::SocketAddr;
2use std::sync::Arc;
3
4use axum::{Router, extract::State, http::StatusCode, response::IntoResponse, routing::get};
5use tokio::net::TcpListener;
6use tracing::info;
7
8use camel_api::HealthChecker;
9
10use crate::PrometheusMetrics;
11
12pub struct MetricsServer;
13
14impl MetricsServer {
15    pub async fn run(addr: SocketAddr, metrics: Arc<PrometheusMetrics>) {
16        Self::run_with_health_checker(addr, metrics, None).await;
17    }
18
19    pub async fn run_with_health_checker(
20        addr: SocketAddr,
21        metrics: Arc<PrometheusMetrics>,
22        checker: Option<HealthChecker>,
23    ) {
24        let health = camel_health::health_router(checker);
25        let app = Router::new()
26            .route("/metrics", get(Self::metrics_handler))
27            .with_state(metrics)
28            .merge(health);
29
30        let listener = tokio::net::TcpListener::bind(addr)
31            .await
32            .unwrap_or_else(|e| panic!("Failed to bind to {}: {}", addr, e));
33
34        info!("Prometheus metrics server listening on {}", addr);
35        axum::serve(listener, app).await.unwrap();
36    }
37
38    pub async fn run_with_listener(listener: TcpListener, metrics: Arc<PrometheusMetrics>) {
39        Self::run_with_listener_and_health_checker(listener, metrics, None).await;
40    }
41
42    pub async fn run_with_listener_and_health_checker(
43        listener: TcpListener,
44        metrics: Arc<PrometheusMetrics>,
45        checker: Option<HealthChecker>,
46    ) {
47        let health = camel_health::health_router(checker);
48        let app = Router::new()
49            .route("/metrics", get(Self::metrics_handler))
50            .with_state(metrics)
51            .merge(health);
52
53        info!(
54            "Prometheus metrics server listening on {}",
55            listener.local_addr().unwrap()
56        );
57        axum::serve(listener, app).await.unwrap();
58    }
59
60    async fn metrics_handler(State(metrics): State<Arc<PrometheusMetrics>>) -> impl IntoResponse {
61        let output = metrics.gather();
62        (
63            StatusCode::OK,
64            [("content-type", "text/plain; version=0.0.4")],
65            output,
66        )
67    }
68}
69
70pub struct MetricsResponse {
71    pub status: u16,
72    pub content_type: String,
73    pub body: String,
74}
75
76pub async fn metrics_handler(metrics: Arc<PrometheusMetrics>) -> MetricsResponse {
77    let output = metrics.gather();
78    MetricsResponse {
79        status: 200,
80        content_type: "text/plain; version=0.0.4".to_string(),
81        body: output,
82    }
83}
84
85#[cfg(test)]
86mod tests {
87    use super::*;
88    use camel_api::metrics::MetricsCollector;
89
90    #[tokio::test]
91    async fn test_metrics_handler_returns_prometheus_format() {
92        let metrics = Arc::new(PrometheusMetrics::new());
93        metrics.increment_exchanges("test-route");
94
95        let response = metrics_handler(metrics).await;
96
97        assert_eq!(response.status, 200);
98        assert_eq!(response.content_type, "text/plain; version=0.0.4");
99        assert!(response.body.contains("camel_exchanges_total"));
100        assert!(response.body.contains("test-route"));
101    }
102
103    #[tokio::test]
104    async fn test_metrics_handler_content_type() {
105        let metrics = Arc::new(PrometheusMetrics::new());
106
107        let response = metrics_handler(metrics).await;
108
109        assert_eq!(response.content_type, "text/plain; version=0.0.4");
110    }
111}
camel_prometheus/server.rs

camel_prometheus/
server.rs
