tests: topotests/ospf_yang_startup_config: verify startup config-file batching

Add a single-router topology that exercises the daemon-direct
startup config-file batching path added by

    lib: batch direct-daemon config-file loads into one NB transaction

The ospfd fixture places

    area 0.0.0.61 default-cost 31
    area 0.0.0.61 stub no-summary

with default-cost *before* the stub-area line. With per-line commit
the first line fails RFC 9129's "default-cost is valid only on
stub/NSSA areas" when clause and the daemon never reaches the
stub-area line. Only the batched path, where the whole file commits
in one northbound transaction, lets the two leaves validate against
each other and both end up in the committed running configuration.

The ospf6d fixture carries a matching stub area without default-cost
(v3 has no default-cost surface) so the v3 startup-batching code path
is exercised too.

The test asserts both stub-area lines are present in show
running-config after the topology has started.

Signed-off-by: Eric Parsonage <eric@eparsonage.com>

Author: lamestllama

tests/topotests/ospf_yang_startup_config/__init__.py

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+

tests/topotests/ospf_yang_startup_config/r1/ospf6d.conf

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+!
+router ospf6
+ ospf6 router-id 10.0.255.1
+ area 0.0.0.62 stub no-summary
+!

tests/topotests/ospf_yang_startup_config/r1/ospfd.conf

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+!
+router ospf
+ ospf router-id 10.0.255.1
+ area 0.0.0.61 default-cost 31
+ area 0.0.0.61 stub no-summary
+!

tests/topotests/ospf_yang_startup_config/r1/zebra.conf

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+!

tests/topotests/ospf_yang_startup_config/test_ospf_yang_startup_config.py

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+#!/usr/bin/env python
+# SPDX-License-Identifier: ISC
+
+"""
+test_ospf_yang_startup_config.py: Test OSPF YANG startup config batching.
+"""
+
+import os
+import sys
+
+import pytest
+
+CWD = os.path.dirname(os.path.realpath(__file__))
+sys.path.append(os.path.join(CWD, "../"))
+
+# pylint: disable=C0413
+from lib.topogen import Topogen, TopoRouter, get_topogen
+
+pytestmark = [pytest.mark.ospfd, pytest.mark.ospf6d]
+
+
+def build_topo(tgen):
+    "Build a single-router topology for startup config parsing."
+    tgen.add_router("r1")
+
+
+def setup_module(mod):
+    "Sets up the pytest environment."
+    tgen = Topogen(build_topo, mod.__name__)
+    tgen.start_topology()
+
+    r1 = tgen.gears["r1"]
+    r1.load_config(TopoRouter.RD_ZEBRA, os.path.join(CWD, "r1/zebra.conf"))
+    r1.load_config(TopoRouter.RD_OSPF, os.path.join(CWD, "r1/ospfd.conf"))
+    r1.load_config(TopoRouter.RD_OSPF6, os.path.join(CWD, "r1/ospf6d.conf"))
+
+    tgen.start_router()
+
+
+def teardown_module():
+    "Teardown the pytest environment."
+    tgen = get_topogen()
+    tgen.stop_topology()
+
+
+def test_ospf_yang_startup_config_file_batching():
+    "Verify direct daemon startup config loads commit cross-leaf OSPF changes."
+    tgen = get_topogen()
+    if tgen.routers_have_failure():
+        pytest.skip("skipped because of router(s) failure")
+
+    r1 = tgen.gears["r1"]
+
+    running = r1.vtysh_cmd("show running-config ospfd")
+    assert "area 0.0.0.61 stub no-summary" in running, running
+    assert "area 0.0.0.61 default-cost 31" in running, running
+
+    running = r1.vtysh_cmd("show running-config ospf6d")
+    assert "area 0.0.0.62 stub no-summary" in running, running