Merge #280: feat: [#279] add domain support for UDP trackers

a8bd087 feat: [#279] add domain support for UDP trackers (Jose Celano)

Pull request description:

  ## Summary

  Closes #279

  Add optional `domain` field to UDP tracker configuration to allow domain names in announce URLs instead of IP addresses. This feature mirrors the existing domain support in HTTP trackers.

  ## Changes

  ### Domain Layer (`src/domain/tracker/config/udp.rs`)
  - Add `domain: Option<DomainName>` field to `UdpTrackerConfig`
  - Include proper serde attributes for optional field serialization

  ### Application Layer
  - **`udp_tracker_section.rs`**: Add `domain: Option<String>` field with validation using `DomainName::new()`
  - **`show/info/tracker.rs`**: Update to use domain for UDP URLs when available

  ### Infrastructure Layer
  - Update all test fixtures with `domain: None` for existing UDP tracker constructions

  ### Schema & Config
  - Regenerate JSON schema with new `domain` field description
  - Update `envs/manual-https-test.json` with example UDP domain

  ## Testing

  - ✅ All unit tests pass (including 16 new tests for domain serialization)
  - ✅ E2E infrastructure lifecycle tests pass
  - ✅ E2E deployment workflow tests pass
  - ✅ All linting checks pass (clippy, rustfmt, markdownlint, yamllint, shellcheck)
  - ✅ Pre-commit verification complete

  ## Example Usage

  ```json
  {
    "trackers": [
      {
        "name": "udp1",
        "udp": {
          "bind_port": 6969,
          "public_port": 6969,
          "domain": "udp1.tracker.example.com"
        }
      }
    ]
  }
  ```

  ## Before/After

  **Before**: UDP URLs used IP addresses only
  ```
  UDP announce URLs:
    Public IPv4: udp://10.123.219.117:6969
    Public IPv6: Not available
  ```

  **After**: UDP URLs use domain when configured
  ```
  UDP announce URLs:
    Public IPv4: udp://udp1.tracker.local:6969
    Public IPv6: Not available
  ```

ACKs for top commit:
  josecelano:
    ACK a8bd087

Tree-SHA512: cbb85da09e46e4df152089f33235aa25bcbfad653343e82a3a170884f07985039b3b7a832f332ace0c942913002d6bb00995b0c62768d03130f8c954dcbd9026

Author: josecelano

schemas/environment-config.json

@@ -1,3 +1,5 @@
+    Finished `dev` profile [unoptimized + debuginfo] target(s) in 0.10s
+     Running `target/debug/torrust-tracker-deployer create schema`
 {
   "$schema": "https://json-schema.org/draft/2020-12/schema",
   "title": "EnvironmentCreationConfig",
@@ -460,6 +462,13 @@
       "properties": {
         "bind_address": {
           "type": "string"
+        },
+        "domain": {
+          "description": "Domain name for the UDP tracker (optional)\n\nWhen present, this domain can be used in announce URLs instead of the IP.\nExample: `udp://tracker.example.com:6969/announce`\n\nNote: Unlike HTTP trackers, UDP does not support TLS, so there is no\n`use_tls_proxy` field for UDP trackers.",
+          "type": [
+            "string",
+            "null"
+          ]
         }
       },
       "required": [

src/application/command_handlers/create/config/environment_config.rs

@@ -504,6 +504,7 @@ impl EnvironmentCreationConfig {
                 },
                 udp_trackers: vec![super::tracker::UdpTrackerSection {
                     bind_address: "0.0.0.0:6969".to_string(),
+                    domain: None,
                 }],
                 http_trackers: vec![super::tracker::HttpTrackerSection {
                     bind_address: "0.0.0.0:7070".to_string(),
@@ -1407,6 +1408,7 @@ mod tests {
             },
             udp_trackers: vec![UdpTrackerSection {
                 bind_address: "0.0.0.0:6969".to_string(),
+                domain: None,
             }],
             http_trackers: vec![HttpTrackerSection {
                 bind_address: "0.0.0.0:7070".to_string(),
@@ -1482,6 +1484,7 @@ mod tests {
             },
             udp_trackers: vec![UdpTrackerSection {
                 bind_address: "0.0.0.0:6969".to_string(),
+                domain: None,
             }],
             http_trackers: vec![HttpTrackerSection {
                 bind_address: "0.0.0.0:7070".to_string(),
@@ -1573,6 +1576,7 @@ mod tests {
             },
             udp_trackers: vec![UdpTrackerSection {
                 bind_address: "0.0.0.0:6969".to_string(),
+                domain: None,
             }],
             http_trackers: vec![HttpTrackerSection {
                 bind_address: "0.0.0.0:7070".to_string(),

src/application/command_handlers/create/config/tracker/tracker_section.rs

@@ -125,6 +125,7 @@ impl Default for TrackerSection {
             },
             udp_trackers: vec![UdpTrackerSection {
                 bind_address: "0.0.0.0:6969".to_string(),
+                domain: None,
             }],
             http_trackers: vec![HttpTrackerSection {
                 bind_address: "0.0.0.0:7070".to_string(),
@@ -161,6 +162,7 @@ mod tests {
             },
             udp_trackers: vec![UdpTrackerSection {
                 bind_address: "0.0.0.0:6969".to_string(),
+                domain: None,
             }],
             http_trackers: vec![HttpTrackerSection {
                 bind_address: "0.0.0.0:7070".to_string(),
@@ -205,9 +207,11 @@ mod tests {
             udp_trackers: vec![
                 UdpTrackerSection {
                     bind_address: "0.0.0.0:6969".to_string(),
+                    domain: None,
                 },
                 UdpTrackerSection {
                     bind_address: "0.0.0.0:6970".to_string(),
+                    domain: None,
                 },
             ],
             http_trackers: vec![
@@ -248,6 +252,7 @@ mod tests {
             },
             udp_trackers: vec![UdpTrackerSection {
                 bind_address: "invalid".to_string(),
+                domain: None,
             }],
             http_trackers: vec![],
             http_api: HttpApiSection {
@@ -279,6 +284,7 @@ mod tests {
             },
             udp_trackers: vec![UdpTrackerSection {
                 bind_address: "0.0.0.0:6969".to_string(),
+                domain: None,
             }],
             http_trackers: vec![HttpTrackerSection {
                 bind_address: "0.0.0.0:7070".to_string(),
@@ -378,6 +384,7 @@ mod tests {
             },
             udp_trackers: vec![UdpTrackerSection {
                 bind_address: "0.0.0.0:7070".to_string(),
+                domain: None,
             }],
             http_trackers: vec![HttpTrackerSection {
                 bind_address: "0.0.0.0:7070".to_string(),

src/application/command_handlers/create/config/tracker/udp_tracker_section.rs

@@ -5,10 +5,21 @@ use serde::{Deserialize, Serialize};
 
 use crate::application::command_handlers::create::config::errors::CreateConfigError;
 use crate::domain::tracker::UdpTrackerConfig;
+use crate::shared::DomainName;
 
 #[derive(Debug, Clone, Serialize, Deserialize, PartialEq, JsonSchema)]
 pub struct UdpTrackerSection {
     pub bind_address: String,
+
+    /// Domain name for the UDP tracker (optional)
+    ///
+    /// When present, this domain can be used in announce URLs instead of the IP.
+    /// Example: `udp://tracker.example.com:6969/announce`
+    ///
+    /// Note: Unlike HTTP trackers, UDP does not support TLS, so there is no
+    /// `use_tls_proxy` field for UDP trackers.
+    #[serde(default, skip_serializing_if = "Option::is_none")]
+    pub domain: Option<String>,
 }
 
 impl UdpTrackerSection {
@@ -18,6 +29,7 @@ impl UdpTrackerSection {
     ///
     /// Returns `CreateConfigError::InvalidBindAddress` if the bind address cannot be parsed as a valid IP:PORT combination.
     /// Returns `CreateConfigError::DynamicPortNotSupported` if port 0 (dynamic port assignment) is specified.
+    /// Returns `CreateConfigError::InvalidDomain` if the domain is invalid.
     pub fn to_udp_tracker_config(&self) -> Result<UdpTrackerConfig, CreateConfigError> {
         // Validate that the bind address can be parsed as SocketAddr
         let bind_address = self.bind_address.parse::<SocketAddr>().map_err(|e| {
@@ -34,8 +46,23 @@ impl UdpTrackerSection {
             });
         }
 
-        // Domain type now uses SocketAddr (Step 0.7 completed)
-        Ok(UdpTrackerConfig { bind_address })
+        // Convert domain to domain type with validation (if present)
+        let domain = match &self.domain {
+            Some(domain_str) => {
+                let domain =
+                    DomainName::new(domain_str).map_err(|e| CreateConfigError::InvalidDomain {
+                        domain: domain_str.clone(),
+                        reason: e.to_string(),
+                    })?;
+                Some(domain)
+            }
+            None => None,
+        };
+
+        Ok(UdpTrackerConfig {
+            bind_address,
+            domain,
+        })
     }
 }
 
@@ -47,6 +74,7 @@ mod tests {
     fn it_should_convert_valid_bind_address_to_udp_tracker_config() {
         let section = UdpTrackerSection {
             bind_address: "0.0.0.0:6969".to_string(),
+            domain: None,
         };
 
         let result = section.to_udp_tracker_config();
@@ -57,12 +85,52 @@ mod tests {
             config.bind_address,
             "0.0.0.0:6969".parse::<SocketAddr>().unwrap()
         );
+        assert!(config.domain.is_none());
+    }
+
+    #[test]
+    fn it_should_convert_with_valid_domain() {
+        let section = UdpTrackerSection {
+            bind_address: "0.0.0.0:6969".to_string(),
+            domain: Some("udp.tracker.local".to_string()),
+        };
+
+        let result = section.to_udp_tracker_config();
+        assert!(result.is_ok());
+
+        let config = result.unwrap();
+        assert_eq!(
+            config.bind_address,
+            "0.0.0.0:6969".parse::<SocketAddr>().unwrap()
+        );
+        assert_eq!(
+            config.domain.as_ref().map(DomainName::as_str),
+            Some("udp.tracker.local")
+        );
+    }
+
+    #[test]
+    fn it_should_fail_for_invalid_domain() {
+        let section = UdpTrackerSection {
+            bind_address: "0.0.0.0:6969".to_string(),
+            domain: Some(String::new()), // Empty domain is invalid
+        };
+
+        let result = section.to_udp_tracker_config();
+        assert!(result.is_err());
+
+        if let Err(CreateConfigError::InvalidDomain { domain, .. }) = result {
+            assert_eq!(domain, "");
+        } else {
+            panic!("Expected InvalidDomain error");
+        }
     }
 
     #[test]
     fn it_should_fail_for_invalid_bind_address() {
         let section = UdpTrackerSection {
             bind_address: "invalid".to_string(),
+            domain: None,
         };
 
         let result = section.to_udp_tracker_config();
@@ -79,6 +147,7 @@ mod tests {
     fn it_should_reject_port_zero() {
         let section = UdpTrackerSection {
             bind_address: "0.0.0.0:0".to_string(),
+            domain: None,
         };
 
         let result = section.to_udp_tracker_config();
@@ -92,20 +161,46 @@ mod tests {
     }
 
     #[test]
-    fn it_should_be_serializable() {
+    fn it_should_be_serializable_without_domain() {
         let section = UdpTrackerSection {
             bind_address: "0.0.0.0:6969".to_string(),
+            domain: None,
         };
 
         let json = serde_json::to_string(&section).unwrap();
         assert!(json.contains("bind_address"));
         assert!(json.contains("0.0.0.0:6969"));
+        // domain should not be present when None (skip_serializing_if)
+        assert!(!json.contains("domain"));
     }
 
     #[test]
-    fn it_should_be_deserializable() {
+    fn it_should_be_serializable_with_domain() {
+        let section = UdpTrackerSection {
+            bind_address: "0.0.0.0:6969".to_string(),
+            domain: Some("udp.tracker.local".to_string()),
+        };
+
+        let json = serde_json::to_string(&section).unwrap();
+        assert!(json.contains("bind_address"));
+        assert!(json.contains("0.0.0.0:6969"));
+        assert!(json.contains("domain"));
+        assert!(json.contains("udp.tracker.local"));
+    }
+
+    #[test]
+    fn it_should_be_deserializable_without_domain() {
         let json = r#"{"bind_address":"0.0.0.0:6969"}"#;
         let section: UdpTrackerSection = serde_json::from_str(json).unwrap();
         assert_eq!(section.bind_address, "0.0.0.0:6969");
+        assert!(section.domain.is_none());
+    }
+
+    #[test]
+    fn it_should_be_deserializable_with_domain() {
+        let json = r#"{"bind_address":"0.0.0.0:6969","domain":"udp.tracker.local"}"#;
+        let section: UdpTrackerSection = serde_json::from_str(json).unwrap();
+        assert_eq!(section.bind_address, "0.0.0.0:6969");
+        assert_eq!(section.domain, Some("udp.tracker.local".to_string()));
     }
 }

src/application/command_handlers/show/info/tracker.rs

@@ -124,6 +124,7 @@ impl ServiceInfo {
     /// * `instance_ip` - The IP address of the deployed instance
     /// * `grafana_config` - Optional Grafana configuration (for TLS domain info)
     #[must_use]
+    #[allow(clippy::too_many_lines)]
     pub fn from_tracker_config(
         tracker_config: &TrackerConfig,
         instance_ip: IpAddr,
@@ -132,7 +133,13 @@ impl ServiceInfo {
         let udp_trackers = tracker_config
             .udp_trackers
             .iter()
-            .map(|udp| format!("udp://{}:{}/announce", instance_ip, udp.bind_address.port()))
+            .map(|udp| {
+                let host = udp
+                    .domain
+                    .as_ref()
+                    .map_or_else(|| instance_ip.to_string(), |d| d.as_str().to_string());
+                format!("udp://{}:{}/announce", host, udp.bind_address.port())
+            })
             .collect();
 
         // Separate HTTP trackers by TLS configuration and localhost status

src/domain/tracker/config/mod.rs

@@ -67,7 +67,7 @@ pub fn is_localhost(addr: &SocketAddr) -> bool {
 ///         private: false,
 ///     },
 ///     udp_trackers: vec![
-///         UdpTrackerConfig { bind_address: "0.0.0.0:6969".parse().unwrap() },
+///         UdpTrackerConfig { bind_address: "0.0.0.0:6969".parse().unwrap(), domain: None },
 ///     ],
 ///     http_trackers: vec![
 ///         HttpTrackerConfig { bind_address: "0.0.0.0:7070".parse().unwrap(), domain: None, use_tls_proxy: false },
@@ -274,7 +274,7 @@ impl TrackerConfig {
     ///         private: false,
     ///     },
     ///     udp_trackers: vec![
-    ///         UdpTrackerConfig { bind_address: "0.0.0.0:6969".parse().unwrap() },
+    ///         UdpTrackerConfig { bind_address: "0.0.0.0:6969".parse().unwrap(), domain: None },
     ///     ],
     ///     http_trackers: vec![
     ///         HttpTrackerConfig { bind_address: "0.0.0.0:7070".parse().unwrap(), domain: None, use_tls_proxy: false },
@@ -537,6 +537,7 @@ impl Default for TrackerConfig {
             },
             udp_trackers: vec![UdpTrackerConfig {
                 bind_address: "0.0.0.0:6969".parse().expect("valid address"),
+                domain: None,
             }],
             http_trackers: vec![HttpTrackerConfig {
                 bind_address: "0.0.0.0:7070".parse().expect("valid address"),
@@ -629,6 +630,7 @@ mod tests {
             },
             udp_trackers: vec![UdpTrackerConfig {
                 bind_address: "0.0.0.0:6868".parse().unwrap(),
+                domain: None,
             }],
             http_trackers: vec![HttpTrackerConfig {
                 bind_address: "0.0.0.0:7070".parse().unwrap(),
@@ -730,6 +732,7 @@ mod tests {
                 },
                 udp_trackers: vec![UdpTrackerConfig {
                     bind_address: "0.0.0.0:6969".parse().unwrap(),
+                    domain: None,
                 }],
                 http_trackers: vec![HttpTrackerConfig {
                     bind_address: "0.0.0.0:7070".parse().unwrap(),
@@ -764,9 +767,11 @@ mod tests {
                 udp_trackers: vec![
                     UdpTrackerConfig {
                         bind_address: "0.0.0.0:7070".parse().unwrap(),
+                        domain: None,
                     },
                     UdpTrackerConfig {
                         bind_address: "0.0.0.0:7070".parse().unwrap(),
+                        domain: None,
                     },
                 ],
                 http_trackers: vec![],
@@ -960,6 +965,7 @@ mod tests {
                 },
                 udp_trackers: vec![UdpTrackerConfig {
                     bind_address: "0.0.0.0:7070".parse().unwrap(),
+                    domain: None,
                 }],
                 http_trackers: vec![HttpTrackerConfig {
                     bind_address: "0.0.0.0:7070".parse().unwrap(),