feat: [#1446] add new metric label server_binding_address_ip_type

Example:

```
udp_tracker_core_requests_received_total{request_kind="connect",server_binding_address_ip_family="inet",server_binding_address_ip_type="plain",server_binding_ip="0.0.0.0",server_binding_port="6969",server_binding_protocol="udp"} 1
```

It's needed to easily filter metric samples to calculate aggregate
values for a given IP family (IPv4 or IPv6).

Author: josecelano

packages/http-tracker-core/src/event.rs

@@ -90,6 +90,10 @@ impl From<ConnectionContext> for LabelSet {
                 label_name!("server_binding_address_ip_type"),
                 LabelValue::new(&connection_context.server.service_binding.bind_address_ip_type().to_string()),
             ),
+            (
+                label_name!("server_binding_address_ip_family"),
+                LabelValue::new(&connection_context.server.service_binding.bind_address_ip_family().to_string()),
+            ),
             (
                 label_name!("server_binding_port"),
                 LabelValue::new(&connection_context.server.service_binding.bind_address().port().to_string()),

packages/primitives/src/service_binding.rs

@@ -1,5 +1,5 @@
 use std::fmt;
-use std::net::SocketAddr;
+use std::net::{IpAddr, SocketAddr};
 
 use serde::{Deserialize, Serialize};
 use url::Url;
@@ -40,11 +40,43 @@ pub enum IpType {
 
 impl fmt::Display for IpType {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
-        let addr_type_str = match self {
+        let ip_type_str = match self {
             Self::Plain => "plain",
             Self::V4MappedV6 => "v4_mapped_v6",
         };
-        write!(f, "{addr_type_str}")
+        write!(f, "{ip_type_str}")
+    }
+}
+
+#[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize, Hash)]
+pub enum IpFamily {
+    // IPv4
+    Inet,
+    // IPv6
+    Inet6,
+}
+
+impl fmt::Display for IpFamily {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        let ip_family_str = match self {
+            Self::Inet => "inet",
+            Self::Inet6 => "inet6",
+        };
+        write!(f, "{ip_family_str}")
+    }
+}
+
+impl From<IpAddr> for IpFamily {
+    fn from(ip: IpAddr) -> Self {
+        if ip.is_ipv4() {
+            return IpFamily::Inet;
+        }
+
+        if ip.is_ipv6() {
+            return IpFamily::Inet6;
+        }
+
+        panic!("Unsupported IP address type: {ip}");
     }
 }
 
@@ -128,6 +160,11 @@ impl ServiceBinding {
         IpType::Plain
     }
 
+    #[must_use]
+    pub fn bind_address_ip_family(&self) -> IpFamily {
+        self.bind_address.ip().into()
+    }
+
     /// # Panics
     ///
     /// It never panics because the URL is always valid.

packages/udp-tracker-core/src/event.rs

@@ -63,6 +63,10 @@ impl From<ConnectionContext> for LabelSet {
                 label_name!("server_binding_address_ip_type"),
                 LabelValue::new(&connection_context.server_service_binding.bind_address_ip_type().to_string()),
             ),
+            (
+                label_name!("server_binding_address_ip_family"),
+                LabelValue::new(&connection_context.server_service_binding.bind_address_ip_family().to_string()),
+            ),
             (
                 label_name!("server_binding_port"),
                 LabelValue::new(&connection_context.server_service_binding.bind_address().port().to_string()),

packages/udp-tracker-server/src/event.rs

@@ -122,6 +122,10 @@ impl From<ConnectionContext> for LabelSet {
                 label_name!("server_binding_address_ip_type"),
                 LabelValue::new(&connection_context.server_service_binding.bind_address_ip_type().to_string()),
             ),
+            (
+                label_name!("server_binding_address_ip_family"),
+                LabelValue::new(&connection_context.server_service_binding.bind_address_ip_family().to_string()),
+            ),
             (
                 label_name!("server_binding_port"),
                 LabelValue::new(&connection_context.server_service_binding.bind_address().port().to_string()),