Draft: OSPF stub plugin

docs/plugins.md

@@ -18,6 +18,7 @@
    plugins/mlag.vtep.md
    plugins/multilab.md
    plugins/node.clone.md
+   plugins/ospf.stub.md
    plugins/vrrp.version.md
    plugins/firewall.zonebased.md
 ```

docs/plugins/ospf.stub.md

@@ -0,0 +1,42 @@
+(plugin-ospf-stub)=
+# Fine-grained Control Over OSPF Area Route Propagation
+
+The **ospf.stub** plugin extends OSPF topology modeling by adding native support for stub, totally stubby, NSSA, 
+and totally NSSA areas. These specialized OSPF area types are commonly used to simplify routing in enterprise networks 
+by reducing the number of LSAs exchanged and minimizing routing table size in remote or branch locations. With this 
+plugin, Netlab will automatically generate the correct configurations on all routers in the area, including the 
+appropriate ABR settings. This makes it easy to model and validate optimized OSPF designs in your lab topologies.
+
+```eval_rst
+.. contents:: Table of Contents
+   :depth: 2
+   :local:
+   :backlinks: none
+```
+
+## Platform support
+
+| Operating system    | Stub areas |
+|---------------------|:----------:|
+| Cumulus 5.x NVUE    |     ✅     |
+| Dell OS10           |     ✅     |
+| FRR                 |     ✅     |
+
+## Using the Plugin
+
+To use the plugin, add it to the **plugin** list in the lab topology:
+
+```
+plugin: [ ...., ospf.stub ]
+```
+
+This enables support for ospf.areas:
+
+```
+module: [ ospf ]
+
+ospf.areas:
+  1:
+    kind: stub
+    no_summarize: True
+```

netsim/extra/ospf.stub/cumulus_nvue.j2

@@ -0,0 +1,10 @@
+{% for id,area in ospf.areas.items() %}
+- set:
+    vrf:
+      default:
+        router:
+          ospf:
+            area: 
+              {{ id | ipv4 }}:
+                type: {{ 'totally-' if area.get('no_summary') else '' }}{{ area.kind }}
+{% endfor %}

netsim/extra/ospf.stub/defaults.yml

@@ -0,0 +1,23 @@
+---
+devices:
+  cumulus_nvue.features.ospf:
+    stub: True
+  dellos10.features.ospf:
+    stub: True
+  frr.features.ospf:
+    stub: True
+  none.features.ospf:
+    stub: True
+
+ospf:
+  attributes:
+    global:
+      areas:
+        type: dict
+        _requires: [ ospf ]
+        _keytype: int
+        _subtype:
+          kind: { 'type': str, 'valid_values': [ stub, nssa ] }
+          no_summary: bool
+    node:
+      areas:

netsim/extra/ospf.stub/dellos10.j2

@@ -0,0 +1,6 @@
+{% set pid = ospf.process|default(1) %}
+
+router ospf {{ pid }}
+{% for id,area in ospf.areas.items() %}
+  area {{ id }} {{ area.kind }}{{ ' no-summary' if area.get('no_summary') else '' }}
+{% endfor %}

netsim/extra/ospf.stub/frr.j2

@@ -0,0 +1,4 @@
+router ospf
+{% for id,area in ospf.areas.items() %}
+  area {{ id }} {{ area.kind }}{{ ' no-summary' if area.get('no_summary') else '' }}
+{% endfor %}

netsim/extra/ospf.stub/plugin.py

@@ -0,0 +1,25 @@
+import typing
+from box import Box
+from netsim import api
+from netsim.augment import devices
+from netsim.utils import log
+
+_config_name = "ospf.stub"
+_require = [ "ospf" ]
+
+def post_transform(topology: Box) -> None:
+  for ndata in topology.nodes.values():
+    if not 'ospf' in ndata.get('module',[]):
+      continue
+    ospf_areas = ndata.get('ospf.areas',{})
+    if not ospf_areas:
+      continue
+    features = devices.get_device_features(ndata,topology.defaults)
+    if 'stub' not in features.ospf:
+      log.error(f"Node {ndata.name} (device {ndata.device}) not supported by the ospf.stub plugin")
+      continue
+    if ndata.get('ospf.area','0.0.0.0') != '0.0.0.0':  # Check if node is an ABR
+      for _,area in ospf_areas.items():
+        area.pop('no_summary',None)
+    global _config_name
+    api.node_config(ndata,_config_name)

tests/integration/ospf.stub/01-ospf-stub.yml

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+---
+plugin: [ ospf.stub ]
+
+module: [ ospf ]
+
+ospf.areas:
+  1:
+    kind: stub
+    no_summary: True
+
+nodes:
+  r1:
+  r2:
+    ospf.area: 1
+  r3:
+
+links:
+- r1:
+  r2:
+  ospf.area: 1
+
+- r1-r3