Updates

examples/custom_design/designs/l3vpn/context/__init__.py

@@ -1,9 +1,8 @@
 from django.core.exceptions import ObjectDoesNotExist
 import ipaddress
-from functools import lru_cache
 
-from nautobot.dcim.models import Device, Interface
-from nautobot.ipam.models import VRF, Prefix
+from nautobot.dcim.models import Device
+from nautobot.ipam.models import VRF
 
 from nautobot_design_builder.context import Context, context_file
 
@@ -19,20 +18,6 @@ class L3VPNContext(Context):
     def __hash__(self):
         return hash((self.pe.name, self.ce.name, self.customer_name))
 
-    @lru_cache
-    def get_l3vpn_prefix(self, parent_prefix, prefix_length):
-        tag = self.design_instance_tag
-        if tag:
-            existing_prefix = Prefix.objects.filter(tags__in=[tag], prefix_length=30).first()
-            if existing_prefix:
-                return str(existing_prefix)
-
-        for new_prefix in ipaddress.ip_network(parent_prefix).subnets(new_prefix=prefix_length):
-            try:
-                Prefix.objects.get(prefix=str(new_prefix))
-            except ObjectDoesNotExist:
-                return new_prefix
-
     def get_customer_id(self, customer_name, l3vpn_asn):
         try:
             vrf = VRF.objects.get(description=f"VRF for customer {customer_name}")
@@ -44,16 +29,6 @@ def get_customer_id(self, customer_name, l3vpn_asn):
             new_id = int(last_vrf.name.split(":")[-1]) + 1
             return str(new_id)
 
-    def get_interface_name(self, device):
-        root_interface_name = "GigabitEthernet"
-        interfaces = Interface.objects.filter(name__contains=root_interface_name, device=device)
-        tag = self.design_instance_tag
-        if tag:
-            existing_interface = interfaces.filter(tags__in=[tag]).first()
-            if existing_interface:
-                return existing_interface.name
-        return f"{root_interface_name}1/{len(interfaces) + 1}"
-
     def get_ip_address(self, prefix, offset):
         net_prefix = ipaddress.ip_network(prefix)
         for count, host in enumerate(net_prefix):

examples/custom_design/designs/l3vpn/designs/0001_ipam.yaml.j2

@@ -1,14 +1,25 @@
 ---
 
-vrfs:
-  - "!create_or_update:name": "{{ l3vpn_asn }}:{{ get_customer_id(customer_name, l3vpn_asn) }}"
-    description: "VRF for customer {{ customer_name }}"
-    "!ref": "my_vrf"
-
+tags:
+    - "!create_or_update:name": "VRF Prefix"
+      "slug": "vrf_prefix"
+    - "!create_or_update:name": "VRF Interface"
+      "slug": "vrf_interface"
 
 prefixes:
     - "!create_or_update:prefix": "{{ l3vpn_prefix }}"
       status__name: "Reserved"
-    - "!create_or_update:prefix": "{{ get_l3vpn_prefix(l3vpn_prefix, l3vpn_prefix_length) }}"
-      status__name: "Reserved"
-      vrf: "!ref:my_vrf"
+
+vrfs:
+  - "!create_or_update:name": "{{ l3vpn_asn }}:{{ get_customer_id(customer_name, l3vpn_asn) }}"
+    description: "VRF for customer {{ customer_name }}"
+    prefixes:
+      - "!next_prefix":
+          identified_by:
+            tags__name: "VRF Prefix"
+          prefix: "{{ l3vpn_prefix }}"
+          length: 30
+        status__name: "Reserved"
+        tags:
+          - {"!get:name": "VRF Prefix"}
+        "!ref": "l3vpn_p2p_prefix"

examples/custom_design/designs/l3vpn/designs/0002_devices.yaml.j2

@@ -8,18 +8,22 @@
       "mpls_router": true,
     }
     interfaces:
-      - "!create_or_update:name": "{{ get_interface_name(device) }}"
+      - "!next_interface": {}
         status__name: "Planned"
         type: "other"
         {% if offset == 2 %}
         "!connect_cable":
           status__name: "Planned"
-          to:
-            device__name: "{{ other_device.name }}"
-            name: "{{ get_interface_name(other_device) }}"
+          to: "!ref:other_interface"
+        {% else %}
+        "!ref": "other_interface"
         {% endif %}
+        tags:
+          - {"!get:name": "VRF Interface"}
         ip_addresses:
-        - "!create_or_update:address": "{{ get_ip_address(get_l3vpn_prefix(l3vpn_prefix, l3vpn_prefix_length), offset) }}"
+        - "!child_prefix:address":
+            parent: "!ref:l3vpn_p2p_prefix"
+            offset: "0.0.0.{{ offset }}/30"
           status__name: "Reserved"
 
 {% endmacro %}

examples/custom_design/designs/l3vpn/jobs.py

@@ -6,11 +6,26 @@
 from nautobot.extras.jobs import ObjectVar, StringVar
 
 from nautobot_design_builder.design_job import DesignJob
+from nautobot_design_builder.design import ModelInstance
+from nautobot_design_builder.ext import AttributeExtension
 from nautobot_design_builder.contrib import ext
 
 from .context import L3VPNContext
 
 
+class NextInterfaceExtension(AttributeExtension):
+    tag = "next_interface"
+
+    def attribute(self, *args, value: ext.Any, model_instance: ModelInstance) -> None:
+        root_interface_name = "GigabitEthernet"
+        interfaces = model_instance.relationship_manager.filter(name__startswith="GigabitEthernet")
+        existing_interface = interfaces.filter(tags__name="VRF Interface").first()
+        if existing_interface:
+            model_instance.instance = existing_interface
+            return {"!create_or_update:name": existing_interface.name}
+        return {"!create_or_update:name": f"{root_interface_name}1/{len(interfaces) + 1}"}
+
+
 class L3vpnDesign(DesignJob):
     """Create a l3vpn connection."""
 
@@ -38,7 +53,12 @@ class Meta:
             "designs/0002_devices.yaml.j2",
         ]
         context_class = L3VPNContext
-        extensions = [ext.CableConnectionExtension]
+        extensions = [
+            ext.CableConnectionExtension,
+            ext.NextPrefixExtension,
+            NextInterfaceExtension,
+            ext.ChildPrefixExtension,
+        ]
 
     @staticmethod
     def validate_data_logic(data):

nautobot_design_builder/context.py

@@ -3,13 +3,12 @@
 from functools import cached_property
 from collections import UserList, UserDict, UserString
 import inspect
-from typing import Any, Union
+from typing import Any
 import yaml
 
 from jinja2.nativetypes import NativeEnvironment
 
 from nautobot.extras.models import JobResult
-from nautobot.extras.models import Tag
 
 from nautobot_design_builder.errors import DesignValidationError
 from nautobot_design_builder.jinja2 import new_template_environment
@@ -371,14 +370,6 @@ def validate(self):
         if len(errors) > 0:
             raise DesignValidationError("\n".join(errors))
 
-    @property
-    def design_instance_tag(self) -> Union[Tag, None]:
-        """Returns the `Tag` of the design instance if exists."""
-        try:
-            return Tag.objects.get(name__contains=self._instance_name)
-        except Tag.DoesNotExist:
-            return None
-
     @property
     def _instance_name(self):
         if nautobot_version < "2.0.0":

nautobot_design_builder/contrib/ext.py

@@ -117,6 +117,12 @@ def lookup(self, queryset, query, parent: ModelInstance = None):
             Any: The object matching the query.
         """
         query = self.environment.resolve_values(query)
+        # it's possible an extension actually returned the instance we need, in
+        # that case, no need to look it up. This is especially true for the
+        # !ref extension used as a value.
+        if isinstance(query, ModelInstance):
+            return query
+
         query = self.flatten_query(query)
         try:
             model_class = self.environment.model_class_index[queryset.model]
@@ -143,6 +149,7 @@ def attribute(self, *args, value, model_instance) -> None:  # pylint:disable=arg
         assign it to an attribute of another object.
 
         Args:
+            *args: Any additional arguments following the tag name. These are `:` delimited.
             value: A filter describing the object to get. Keys should map to lookup
             parameters equivalent to Django's `filter()` syntax for the given model.
             The special `type` parameter will override the relationship's model class
@@ -230,10 +237,12 @@ def get_query_managers(endpoint_type):
 
         return query_managers
 
-    def attribute(self, value, model_instance) -> None:
+    def attribute(self, *args, value=None, model_instance: ModelInstance = None) -> None:
         """Connect a cable termination to another cable termination.
 
         Args:
+            *args: Any additional arguments following the tag name. These are `:` delimited.
+
             value: Dictionary with details about the cable. At a minimum
             the dictionary must have a `to` key which includes a query
             dictionary that will return exactly one object to be added to the
@@ -313,10 +322,12 @@ class NextPrefixExtension(AttributeExtension):
 
     tag = "next_prefix"
 
-    def attribute(self, value: dict, model_instance) -> None:
+    def attribute(self, *args, value: dict = None, model_instance: ModelInstance = None) -> None:
         """Provides the `!next_prefix` attribute that will calculate the next available prefix.
 
         Args:
+            *args: Any additional arguments following the tag name. These are `:` delimited.
+
             value: A filter describing the parent prefix to provision from. If `prefix`
                 is one of the query keys then the network and prefix length will be
                 split and used as query arguments for the underlying Prefix object. The
@@ -339,12 +350,20 @@ def attribute(self, value: dict, model_instance) -> None:
                     - "10.0.0.0/23"
                     - "10.0.2.0/23"
                     length: 24
+                    identified_by:
+                        tag__name: "some tag name"
                 status__name: "Active"
             ```
         """
         if not isinstance(value, dict):
             raise DesignImplementationError("the next_prefix tag requires a dictionary of arguments")
-
+        identified_by = value.pop("identified_by", None)
+        if identified_by:
+            try:
+                model_instance.instance = model_instance.relationship_manager.get(**identified_by)
+                return
+            except ObjectDoesNotExist:
+                pass
         length = value.pop("length", None)
         if length is None:
             raise DesignImplementationError("the next_prefix tag requires a prefix length")
@@ -400,7 +419,7 @@ class ChildPrefixExtension(AttributeExtension):
 
     tag = "child_prefix"
 
-    def attribute(self, value: dict, model_instance) -> None:
+    def attribute(self, attr: str = "prefix", value: dict = {}, model_instance=None) -> None:
         """Provides the `!child_prefix` attribute.
 
         !child_prefix calculates a child prefix using a parent prefix
@@ -457,7 +476,7 @@ def attribute(self, value: dict, model_instance) -> None:
         if not isinstance(offset, str):
             raise DesignImplementationError("offset must be string")
 
-        return "prefix", network_offset(parent, offset)
+        return attr, network_offset(parent, offset)
 
 
 class BGPPeeringExtension(AttributeExtension):
@@ -486,14 +505,16 @@ def __init__(self, environment: Environment):
                 "the `bgp_peering` tag can only be used when the bgp models app is installed."
             )
 
-    def attribute(self, value, model_instance) -> None:
+    def attribute(self, *args, value=None, model_instance: ModelInstance = None) -> None:
         """This attribute tag creates or updates a BGP peering for two endpoints.
 
         !bgp_peering will take an `endpoint_a` and `endpoint_z` argument to correctly
         create or update a BGP peering. Both endpoints can be specified using typical
         Design Builder syntax.
 
         Args:
+            *args: Any additional arguments following the tag name. These are `:` delimited.
+
             value (dict): dictionary containing the keys `endpoint_a`
             and `endpoint_z`. Both of these keys must be dictionaries
             specifying a way to either lookup or create the appropriate

nautobot_design_builder/design.py

@@ -637,6 +637,12 @@ def _send(self, signal: str):
         self.metadata.send(signal)
 
     def _load_instance(self):  # pylint: disable=too-many-branches
+        # Short circuit if the instance was loaded earlier in
+        # the initialization process
+        if self.instance is not None:
+            self._initial_state = serialize_object_v2(self.instance)
+            return
+
         query_filter = self.metadata.query_filter
         field_values = self.metadata.query_filter_values
         if self.metadata.action == ModelMetadata.GET:

nautobot_design_builder/design_job.py

@@ -299,7 +299,6 @@ def _run_in_transaction(self, **kwargs):  # pylint: disable=too-many-branches, t
             if previous_journal:
                 deleted_object_ids = previous_journal - journal
                 if deleted_object_ids:
-                    self.log_debug(f"Deleting {list(deleted_object_ids)}")
                     journal.design_instance.decommission(*deleted_object_ids, local_logger=self.logger)
                     self.post_implementation(context, self.environment)
 

nautobot_design_builder/ext.py

@@ -100,12 +100,18 @@ class AttributeExtension(Extension, ABC):
     """An `AttributeExtension` will be evaluated when the design key matches the `tag`."""
 
     @abstractmethod
-    def attribute(self, value: Any, model_instance: "ModelInstance") -> None:
+    def attribute(self, *args, value: Any = None, model_instance: "ModelInstance" = None) -> None:
         """This method is called when the `attribute_tag` is encountered.
 
+        Note: The method signature must match the above for the extension to work. The
+        extension name is parsed by splitting on `:` symbols and the result is passed as the
+        varargs. For instance, if the attribute tag is `mytagg` and it is called with `!mytagg:arg1`: {} then
+        `*args` will be ['arg1'] and `value` will be the empty dictionary.
+
         Args:
+            *args: Any additional arguments following the tag name. These are `:` delimited.
             value (Any): The value of the data structure at this key's point in the design YAML. This could be a scalar, a dict or a list.
-            model_instance (CreatorObject): Object is the CreatorObject that would ultimately contain the values.
+            model_instance (ModelInstance): Object is the ModelInstance that would ultimately contain the values.
         """
 
 
@@ -151,10 +157,12 @@ def __init__(self, environment: "Environment"):  # noqa: D107
         super().__init__(environment)
         self._env = {}
 
-    def attribute(self, value, model_instance):
+    def attribute(self, *args, value, model_instance):
         """This method is called when the `!ref` tag is encountered.
 
         Args:
+            *args: Any additional arguments following the tag name. These are `:` delimited.
+
             value (Any): Value should be a string name (the reference) to refer to the object
             model_instance (CreatorObject): The object that will be later referenced
 
@@ -243,7 +251,7 @@ def _reset(self):
             "directories": [],
         }
 
-    def attribute(self, value, model_instance):
+    def attribute(self, *args, value=None, model_instance: "ModelInstance" = None):
         """Provide the attribute tag functionality for git_context.
 
         Args: