feat: network monitoring from agents (#2266, #1911)

Co-authored-by: Sven van Ginkel <svenvanginkel@icloud.com>
Co-authored-by: xiaomiku01 <xiaomiku01@outlook.com>

agent/agent.go

@@ -48,6 +48,7 @@ type Agent struct {
 	keys                      []gossh.PublicKey                                     // SSH public keys
 	smartManager              *SmartManager                                         // Manages SMART data
 	systemdManager            *systemdManager                                       // Manages systemd services
+	monitorManager            *MonitorManager                                       // Manages network monitors
 	storagePoolManager        *StoragePoolManager                                   // Manages storage pool and dataset data
 }
 
@@ -122,6 +123,9 @@ func NewAgent(dataDir ...string) (agent *Agent, err error) {
 	// initialize handler registry
 	agent.handlerRegistry = NewHandlerRegistry()
 
+	// initialize monitor manager
+	agent.monitorManager = newMonitorManager()
+
 	agent.storagePoolManager = newStoragePoolManager()
 
 	// Retain ZFS_INTERVAL for the shared storage pool detail refresh interval.
@@ -192,6 +196,11 @@ func (a *Agent) gatherStats(options common.DataRequestOptions) *system.CombinedD
 		}
 	}
 
+	if a.monitorManager != nil {
+		data.Monitors = a.monitorManager.GetResults(cacheTimeMs)
+		slog.Debug("Monitors", "data", data.Monitors)
+	}
+
 	// skip updating systemd services if cache time is not the default 60sec interval
 	if a.systemdManager != nil && cacheTimeMs == defaultDataCacheTimeMs {
 		totalCount := uint16(a.systemdManager.getServiceStatsCount())