feat: add network monitors (ICMP/TCP/HTTP/DNS) (#2266)

Co-authored-by: xiaomiku01 <xiaomiku01@outlook.com>
Co-authored-by: henrygd <hank@henrygd.me>

internal/hub/utils/utils.go

@@ -1,7 +1,11 @@
 // Package utils provides utility functions for the hub.
 package utils
 
-import "os"
+import (
+	"os"
+
+	"github.com/pocketbase/pocketbase/core"
+)
 
 // GetEnv retrieves an environment variable with a "BESZEL_HUB_" prefix, or falls back to the unprefixed key.
 func GetEnv(key string) (value string, exists bool) {
@@ -10,3 +14,26 @@ func GetEnv(key string) (value string, exists bool) {
 	}
 	return os.LookupEnv(key)
 }
+
+// realtimeActiveForCollection checks if there are active WebSocket subscriptions for the given collection.
+func RealtimeActiveForCollection(app core.App, collectionName string, validateFn func(filterQuery string) bool) bool {
+	broker := app.SubscriptionsBroker()
+	if broker.TotalClients() == 0 {
+		return false
+	}
+	for _, client := range broker.Clients() {
+		subs := client.Subscriptions(collectionName)
+		if len(subs) > 0 {
+			if validateFn == nil {
+				return true
+			}
+			for k := range subs {
+				filter := subs[k].Query["filter"]
+				if validateFn(filter) {
+					return true
+				}
+			}
+		}
+	}
+	return false
+}