2755 Add ability to extend HostNode, NetworkNode, Service and Application outside PrimAITE.

src/primaite/simulator/network/hardware/base.py

@@ -1699,7 +1699,7 @@ class Node(SimComponent):
             if self.software_manager.software.get(application_name):
                 self.sys_log.warning(f"Can't install {application_name}. It's already installed.")
                 return RequestResponse(status="success", data={"reason": "already installed"})
-            application_class = Application._application_registry[application_name]
+            application_class = Application._registry[application_name]
             self.software_manager.install(application_class)
             application_instance = self.software_manager.software.get(application_name)
             self.applications[application_instance.uuid] = application_instance

src/primaite/simulator/network/hardware/nodes/host/host_node.py

@@ -2,7 +2,7 @@
 from __future__ import annotations
 
 from ipaddress import IPv4Address
-from typing import Any, ClassVar, Dict, Optional
+from typing import Any, ClassVar, Dict, Optional, Type
 
 from primaite import getLogger
 from primaite.simulator.network.hardware.base import (
@@ -325,10 +325,30 @@ class HostNode(Node):
     network_interface: Dict[int, NIC] = {}
     "The NICs on the node by port id."
 
+    _registry: ClassVar[Dict[str, Type["HostNode"]]] = {}
+    """Registry of application types. Automatically populated when subclasses are defined."""
+
     def __init__(self, ip_address: IPV4Address, subnet_mask: IPV4Address, **kwargs):
         super().__init__(**kwargs)
         self.connect_nic(NIC(ip_address=ip_address, subnet_mask=subnet_mask))
 
+    def __init_subclass__(cls, identifier: str = 'default', **kwargs: Any) -> None:
+        """
+        Register a hostnode type.
+
+        :param identifier: Uniquely specifies an hostnode class by name. Used for finding items by config.
+        :type identifier: str
+        :raises ValueError: When attempting to register an hostnode with a name that is already allocated.
+        """
+        if identifier == 'default':
+            return
+        # Enforce lowercase registry entries because it makes comparisons everywhere else much easier.
+        identifier = identifier.lower()
+        super().__init_subclass__(**kwargs)
+        if identifier in cls._registry:
+            raise ValueError(f"Tried to define new hostnode {identifier}, but this name is already reserved.")
+        cls._registry[identifier] = cls
+
     @property
     def nmap(self) -> Optional[NMAP]:
         """

src/primaite/simulator/network/hardware/nodes/network/network_node.py

@@ -1,6 +1,6 @@
 # © Crown-owned copyright 2024, Defence Science and Technology Laboratory UK
 from abc import abstractmethod
-from typing import Optional
+from typing import Any, ClassVar, Dict, Optional, Type
 
 from primaite.simulator.network.hardware.base import NetworkInterface, Node
 from primaite.simulator.network.transmission.data_link_layer import Frame
@@ -16,6 +16,25 @@ class NetworkNode(Node):
     provide functionality for receiving and processing frames received on their network interfaces.
     """
 
+    _registry: ClassVar[Dict[str, Type["NetworkNode"]]] = {}
+    """Registry of application types. Automatically populated when subclasses are defined."""
+
+    def __init_subclass__(cls, identifier: str = 'default', **kwargs: Any) -> None:
+        """
+        Register a networknode type.
+
+        :param identifier: Uniquely specifies an networknode class by name. Used for finding items by config.
+        :type identifier: str
+        :raises ValueError: When attempting to register an networknode with a name that is already allocated.
+        """
+        if identifier == 'default':
+            return
+        identifier = identifier.lower()
+        super().__init_subclass__(**kwargs)
+        if identifier in cls._registry:
+            raise ValueError(f"Tried to define new networknode {identifier}, but this name is already reserved.")
+        cls._registry[identifier] = cls
+
     @abstractmethod
     def receive_frame(self, frame: Frame, from_network_interface: NetworkInterface):
         """