new IP trunk migration

Add IP trunk migration, including a refactor of the IP trunk model

gso/products/product_blocks/router.py

@@ -4,6 +4,7 @@ from typing import Optional
 
 from orchestrator.domain.base import ProductBlockModel
 from orchestrator.types import SubscriptionLifecycle, strEnum
+from pydantic import ConstrainedInt
 
 from gso.products.product_blocks.site import SiteBlock, SiteBlockInactive, SiteBlockProvisioning
 
@@ -28,13 +29,25 @@ class RouterRole(strEnum):
     """AMT router."""
 
 
+class PortNumber(ConstrainedInt):
+    """Constrained integer for valid port numbers.
+
+    The range from 49152 to 65535 is marked as ephemeral, and can therefore not be selected for permanent allocation.
+    """
+
+    gt = 0
+    """The lower bound of the valid port number range."""
+    le = 49151
+    """As mentioned earlier, the ephemeral port range should not be chosen, and is therefore not available."""
+
+
 class RouterBlockInactive(
     ProductBlockModel, lifecycle=[SubscriptionLifecycle.INITIAL], product_block_name="RouterBlock"
 ):
     """A router that's being currently inactive. See {class}`RouterBlock`."""
 
     router_fqdn: Optional[str] = None
-    router_ts_port: Optional[int] = None
+    router_ts_port: Optional[PortNumber] = None
     router_access_via_ts: Optional[bool] = None
     router_lo_ipv4_address: Optional[ipaddress.IPv4Address] = None
     router_lo_ipv6_address: Optional[ipaddress.IPv6Address] = None
@@ -52,7 +65,7 @@ class RouterBlockProvisioning(RouterBlockInactive, lifecycle=[SubscriptionLifecy
     """A router that's being provisioned. See {class}`RouterBlock`."""
 
     router_fqdn: str
-    router_ts_port: int
+    router_ts_port: PortNumber
     router_access_via_ts: Optional[bool] = None
     router_lo_ipv4_address: Optional[ipaddress.IPv4Address] = None
     router_lo_ipv6_address: Optional[ipaddress.IPv6Address] = None
@@ -71,9 +84,8 @@ class RouterBlock(RouterBlockProvisioning, lifecycle=[SubscriptionLifecycle.ACTI
 
     router_fqdn: str
     """{term}`FQDN` of a router."""
-    router_ts_port: int
-    """The port of the terminal server that this router is connected to. Used for the same reason as mentioned
-    previously."""
+    router_ts_port: PortNumber
+    """The port of the terminal server that this router is connected to. Used to provide out of band access."""
     router_access_via_ts: bool
     """Whether this router should be accessed through the terminal server, or through its loopback address."""
     router_lo_ipv4_address: ipaddress.IPv4Address