feat: [#1403] add extendable-labeled metrics to udp-tracker-server

Author: josecelano

Cargo.lock

@@ -11,6 +11,12 @@ impl LabelValue {
     pub fn new(value: &str) -> Self {
         Self(value.to_owned())
     }
+
+    /// Empty label values are ignored in Prometheus.
+    #[must_use]
+    pub fn ignore() -> Self {
+        Self(String::default())
+    }
 }
 
 impl PrometheusSerializable for LabelValue {

packages/metrics/src/label/value.rs

@@ -77,7 +77,7 @@ pub async fn get_metrics(
             udp6_connections_handled: stats.udp6_connections_handled,
             udp6_announces_handled: stats.udp6_announces_handled,
             udp6_scrapes_handled: stats.udp6_scrapes_handled,
-            // Samples
+            // Extendable metrics
             metric_collection: stats.metric_collection.clone(),
         },
     }

packages/udp-tracker-core/src/statistics/services.rs

@@ -23,12 +23,14 @@ derive_more = { version = "2", features = ["as_ref", "constructor", "from"] }
 futures = "0"
 futures-util = "0"
 ringbuf = "0"
+serde = "1.0.219"
 thiserror = "2"
 tokio = { version = "1", features = ["macros", "net", "rt-multi-thread", "signal", "sync"] }
 torrust-server-lib = { version = "3.0.0-develop", path = "../server-lib" }
 torrust-tracker-clock = { version = "3.0.0-develop", path = "../clock" }
 torrust-tracker-configuration = { version = "3.0.0-develop", path = "../configuration" }
 torrust-tracker-located-error = { version = "3.0.0-develop", path = "../located-error" }
+torrust-tracker-metrics = { version = "3.0.0-develop", path = "../metrics" }
 torrust-tracker-primitives = { version = "3.0.0-develop", path = "../primitives" }
 tracing = "0"
 url = { version = "2", features = ["serde"] }

packages/udp-tracker-server/Cargo.toml

@@ -1,6 +1,8 @@
+use std::fmt;
 use std::net::SocketAddr;
 use std::time::Duration;
 
+use torrust_tracker_metrics::label::{LabelName, LabelSet, LabelValue};
 use torrust_tracker_primitives::service_binding::ServiceBinding;
 
 pub mod sender;
@@ -38,6 +40,17 @@ pub enum UdpRequestKind {
     Scrape,
 }
 
+impl fmt::Display for UdpRequestKind {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        let proto_str = match self {
+            UdpRequestKind::Connect => "connect",
+            UdpRequestKind::Announce => "announce",
+            UdpRequestKind::Scrape => "scrape",
+        };
+        write!(f, "{proto_str}")
+    }
+}
+
 #[derive(Debug, PartialEq, Eq, Clone)]
 pub enum UdpResponseKind {
     Ok {
@@ -76,3 +89,22 @@ impl ConnectionContext {
         self.server_service_binding.bind_address()
     }
 }
+
+impl From<ConnectionContext> for LabelSet {
+    fn from(connection_context: ConnectionContext) -> Self {
+        LabelSet::from([
+            (
+                LabelName::new("server_binding_protocol"),
+                LabelValue::new(&connection_context.server_service_binding.protocol().to_string()),
+            ),
+            (
+                LabelName::new("server_binding_ip"),
+                LabelValue::new(&connection_context.server_service_binding.bind_address().ip().to_string()),
+            ),
+            (
+                LabelName::new("server_binding_port"),
+                LabelValue::new(&connection_context.server_service_binding.bind_address().port().to_string()),
+            ),
+        ])
+    }
+}