fix(opnsense-config): ensure load balancer service configuration is idempotent (#129)

The previous implementation blindly added HAProxy components without checking for existing configurations on the same port, which caused duplicate entries and errors when a service was updated.

This commit refactors the logic to a robust "remove-then-add" strategy. The configure_service method now finds and removes any existing frontend and its dependent components (backend, servers, health check) before adding the new, complete service definition.

This change makes the process fully idempotent, preventing configuration drift and ensuring a predictable state.

Co-authored-by: Ian Letourneau <letourneau.ian@gmail.com>
Reviewed-on: #129

harmony/src/domain/topology/load_balancer.rs

@@ -28,13 +28,7 @@ pub trait LoadBalancer: Send + Sync {
         &self,
         service: &LoadBalancerService,
     ) -> Result<(), ExecutorError> {
-        debug!(
-            "Listing LoadBalancer services {:?}",
-            self.list_services().await
-        );
-        if !self.list_services().await.contains(service) {
-            self.add_service(service).await?;
-        }
+        self.add_service(service).await?;
         Ok(())
     }
 }

harmony/src/infra/opnsense/load_balancer.rs

@@ -26,19 +26,13 @@ impl LoadBalancer for OPNSenseFirewall {
     }
 
     async fn add_service(&self, service: &LoadBalancerService) -> Result<(), ExecutorError> {
-        warn!(
-            "TODO : the current implementation does not check / cleanup / merge with existing haproxy services properly. Make sure to manually verify that the configuration is correct after executing any operation here"
-        );
         let mut config = self.opnsense_config.write().await;
+        let mut load_balancer = config.load_balancer();
+
         let (frontend, backend, servers, healthcheck) =
             harmony_load_balancer_service_to_haproxy_xml(service);
-        let mut load_balancer = config.load_balancer();
-        load_balancer.add_backend(backend);
-        load_balancer.add_frontend(frontend);
-        load_balancer.add_servers(servers);
-        if let Some(healthcheck) = healthcheck {
-            load_balancer.add_healthcheck(healthcheck);
-        }
+
+        load_balancer.configure_service(frontend, backend, servers, healthcheck);
 
         Ok(())
     }
@@ -106,7 +100,7 @@ pub(crate) fn haproxy_xml_config_to_harmony_loadbalancer(
                 .backends
                 .backends
                 .iter()
-                .find(|b| b.uuid == frontend.default_backend);
+                .find(|b| Some(b.uuid.clone()) == frontend.default_backend);
 
             let mut health_check = None;
             match matching_backend {
@@ -116,8 +110,7 @@ pub(crate) fn haproxy_xml_config_to_harmony_loadbalancer(
                 }
                 None => {
                     warn!(
-                        "HAProxy config could not find a matching backend for frontend {:?}",
-                        frontend
+                        "HAProxy config could not find a matching backend for frontend {frontend:?}"
                     );
                 }
             }
@@ -152,11 +145,11 @@ pub(crate) fn get_servers_for_backend(
         .servers
         .iter()
         .filter_map(|server| {
+            let address = server.address.clone()?;
+            let port = server.port?;
+
             if backend_servers.contains(&server.uuid.as_str()) {
-                return Some(BackendServer {
-                    address: server.address.clone(),
-                    port: server.port,
-                });
+                return Some(BackendServer { address, port });
             }
             None
         })
@@ -347,7 +340,7 @@ pub(crate) fn harmony_load_balancer_service_to_haproxy_xml(
         name: format!("frontend_{}", service.listening_port),
         bind: service.listening_port.to_string(),
         mode: "tcp".to_string(), // TODO do not depend on health check here
-        default_backend: backend.uuid.clone(),
+        default_backend: Some(backend.uuid.clone()),
         ..Default::default()
     };
     info!("HAPRoxy frontend and backend mode currently hardcoded to tcp");
@@ -361,8 +354,8 @@ fn server_to_haproxy_server(server: &BackendServer) -> HAProxyServer {
         uuid: Uuid::new_v4().to_string(),
         name: format!("{}_{}", &server.address, &server.port),
         enabled: 1,
-        address: server.address.clone(),
-        port: server.port,
+        address: Some(server.address.clone()),
+        port: Some(server.port),
         mode: "active".to_string(),
         server_type: "static".to_string(),
         ..Default::default()
@@ -385,8 +378,8 @@ mod tests {
         let mut haproxy = HAProxy::default();
         let server = HAProxyServer {
             uuid: "server1".to_string(),
-            address: "192.168.1.1".to_string(),
-            port: 80,
+            address: Some("192.168.1.1".to_string()),
+            port: Some(80),
             ..Default::default()
         };
         haproxy.servers.servers.push(server);
@@ -411,8 +404,8 @@ mod tests {
         let mut haproxy = HAProxy::default();
         let server = HAProxyServer {
             uuid: "server1".to_string(),
-            address: "192.168.1.1".to_string(),
-            port: 80,
+            address: Some("192.168.1.1".to_string()),
+            port: Some(80),
             ..Default::default()
         };
         haproxy.servers.servers.push(server);
@@ -431,8 +424,8 @@ mod tests {
         let mut haproxy = HAProxy::default();
         let server = HAProxyServer {
             uuid: "server1".to_string(),
-            address: "192.168.1.1".to_string(),
-            port: 80,
+            address: Some("192.168.1.1".to_string()),
+            port: Some(80),
             ..Default::default()
         };
         haproxy.servers.servers.push(server);
@@ -453,16 +446,16 @@ mod tests {
         let mut haproxy = HAProxy::default();
         let server = HAProxyServer {
             uuid: "server1".to_string(),
-            address: "some-hostname.test.mcd".to_string(),
-            port: 80,
+            address: Some("some-hostname.test.mcd".to_string()),
+            port: Some(80),
             ..Default::default()
         };
         haproxy.servers.servers.push(server);
 
         let server = HAProxyServer {
             uuid: "server2".to_string(),
-            address: "192.168.1.2".to_string(),
-            port: 8080,
+            address: Some("192.168.1.2".to_string()),
+            port: Some(8080),
             ..Default::default()
         };
         haproxy.servers.servers.push(server);

harmony/src/modules/okd/bootstrap_load_balancer.rs

@@ -77,6 +77,8 @@ impl OKDBootstrapLoadBalancerScore {
             address: topology.bootstrap_host.ip.to_string(),
             port,
         });
+
+        backend.dedup();
         backend
     }
 }