tests/topotests/bgp_llgr/test_bgp_llgr.py

   1 #!/usr/bin/env python
   2 # SPDX-License-Identifier: ISC
   3
   4 # Copyright (c) 2021 by
   5 # Donatas Abraitis <donatas.abraitis@gmail.com>
   6 #
   7
   8 """
   9 Test if BGP Long-lived Graceful Restart capability works:
  10     Check if we can see 172.16.1.1/32 after initial converge in R3.
  11     Check if we can see 172.16.1.1/32 as best selected due to higher weigth in R2.
  12     Kill bgpd in R1.
  13     Check if we can see 172.16.1.1/32 as stale in R2.
  14     Check if we can see 172.16.1.1/32 depreferenced due to LLGR_STALE in R2.
  15     Check if we can see 172.16.1.1/32 after R1 was killed in R3.
  16 """
  17
  18 import os
  19 import sys
  20 import json
  21 import pytest
  22 import functools
  23
  24 pytestmark = [pytest.mark.bgpd]
  25
  26 CWD = os.path.dirname(os.path.realpath(__file__))
  27 sys.path.append(os.path.join(CWD, "../"))
  28
  29 # pylint: disable=C0413
  30 from lib import topotest
  31 from lib.topogen import Topogen, TopoRouter, get_topogen
  32
  33 from lib.common_config import (
  34     kill_router_daemons,
  35     start_router_daemons,
  36     step,
  37 )
  38
  39 pytestmark = [pytest.mark.bgpd]
  40
  41
  42 def build_topo(tgen):
  43     for routern in range(0, 6):
  44         tgen.add_router("r{}".format(routern))
  45
  46     switch = tgen.add_switch("s0")
  47     switch.add_link(tgen.gears["r0"])
  48     switch.add_link(tgen.gears["r2"])
  49
  50     switch = tgen.add_switch("s1")
  51     switch.add_link(tgen.gears["r1"])
  52     switch.add_link(tgen.gears["r2"])
  53
  54     switch = tgen.add_switch("s2")
  55     switch.add_link(tgen.gears["r2"])
  56     switch.add_link(tgen.gears["r3"])
  57
  58     # Dynamic neighbor
  59     switch = tgen.add_switch("s3")
  60     switch.add_link(tgen.gears["r2"])
  61     switch.add_link(tgen.gears["r4"])
  62
  63
  64 def setup_module(mod):
  65     tgen = Topogen(build_topo, mod.__name__)
  66     tgen.start_topology()
  67
  68     router_list = tgen.routers()
  69
  70     for i, (rname, router) in enumerate(router_list.items(), 1):
  71         router.load_config(
  72             TopoRouter.RD_ZEBRA, os.path.join(CWD, "{}/zebra.conf".format(rname))
  73         )
  74         router.load_config(
  75             TopoRouter.RD_BGP, os.path.join(CWD, "{}/bgpd.conf".format(rname))
  76         )
  77
  78     tgen.start_router()
  79
  80
  81 def teardown_module(mod):
  82     tgen = get_topogen()
  83     tgen.stop_topology()
  84
  85
  86 def test_bgp_llgr():
  87     tgen = get_topogen()
  88
  89     if tgen.routers_have_failure():
  90         pytest.skip(tgen.errors)
  91
  92     r2 = tgen.gears["r2"]
  93     r3 = tgen.gears["r3"]
  94
  95     def _bgp_converge(router):
  96         output = json.loads(router.vtysh_cmd("show ip bgp json"))
  97         expected = {
  98             "routes": {
  99                 "172.16.1.1/32": [{"nexthops": [{"ip": "192.168.2.2", "used": True}]}],
 100                 "172.16.1.2/32": [{"nexthops": [{"ip": "192.168.2.2", "used": True}]}],
 101             }
 102         }
 103         return topotest.json_cmp(output, expected)
 104
 105     step("Check if we can see 172.16.1.1/32 after initial converge in R3")
 106     test_func = functools.partial(_bgp_converge, r3)
 107     _, result = topotest.run_and_expect(test_func, None, count=60, wait=0.5)
 108     assert result is None, "Cannot see 172.16.1.1/32 in r3"
 109
 110     def _bgp_weight_prefered_route(router):
 111         output = json.loads(router.vtysh_cmd("show ip bgp 172.16.1.1/32 json"))
 112         expected = {
 113             "paths": [
 114                 {
 115                     "bestpath": {"selectionReason": "Weight"},
 116                     "nexthops": [
 117                         {
 118                             "ip": "192.168.1.1",
 119                         }
 120                     ],
 121                 }
 122             ]
 123         }
 124         return topotest.json_cmp(output, expected)
 125
 126     step(
 127         "Check if we can see 172.16.1.1/32 as best selected due to higher weigth in R2"
 128     )
 129     test_func = functools.partial(_bgp_weight_prefered_route, r2)
 130     _, result = topotest.run_and_expect(test_func, None, count=60, wait=0.5)
 131     assert (
 132         result is None
 133     ), "Prefix 172.16.1.1/32 is not selected as bests path due to weight"
 134
 135     step("Kill bgpd in R1")
 136     kill_router_daemons(tgen, "r1", ["bgpd"])
 137
 138     def _bgp_stale_route(router, prefix):
 139         output = json.loads(router.vtysh_cmd("show ip bgp {} json".format(prefix)))
 140         expected = {"paths": [{"community": {"string": "llgr-stale"}, "stale": True}]}
 141         return topotest.json_cmp(output, expected)
 142
 143     step("Check if we can see 172.16.1.1/32 as stale in R2")
 144     test_func = functools.partial(_bgp_stale_route, r2, "172.16.1.1/32")
 145     _, result = topotest.run_and_expect(test_func, None, count=60, wait=0.5)
 146     assert result is None, "Prefix 172.16.1.1/32 is not stale"
 147
 148     def _bgp_llgr_depreference_route(router):
 149         output = json.loads(router.vtysh_cmd("show ip bgp 172.16.1.1/32 json"))
 150         expected = {
 151             "paths": [
 152                 {
 153                     "bestpath": {"selectionReason": "First path received"},
 154                     "nexthops": [
 155                         {
 156                             "ip": "192.168.0.1",
 157                         }
 158                     ],
 159                 }
 160             ]
 161         }
 162         return topotest.json_cmp(output, expected)
 163
 164     step("Check if we can see 172.16.1.1/32 depreferenced due to LLGR_STALE in R2")
 165     test_func = functools.partial(_bgp_llgr_depreference_route, r2)
 166     _, result = topotest.run_and_expect(test_func, None, count=60, wait=0.5)
 167     assert result is None, "Prefix 172.16.1.1/32 is not depreferenced due to LLGR_STALE"
 168
 169     step("Check if we can see 172.16.1.1/32 after R1 was killed in R3")
 170     test_func = functools.partial(_bgp_converge, r3)
 171     _, result = topotest.run_and_expect(test_func, None, count=60, wait=0.5)
 172     assert result is None, "Cannot see 172.16.1.1/32 in r3"
 173
 174     step("Kill bgpd in R4 (dynamic peer)")
 175     kill_router_daemons(tgen, "r4", ["bgpd"])
 176
 177     step("Check if we can see 172.16.1.2/32 after R4 (dynamic peer) was killed")
 178     test_func = functools.partial(_bgp_stale_route, r2, "172.16.1.2/32")
 179     _, result = topotest.run_and_expect(test_func, None, count=120, wait=0.5)
 180     assert result is None, "Cannot see 172.16.1.2/32 in r2"
 181
 182
 183 if __name__ == "__main__":
 184     args = ["-s"] + sys.argv[1:]
 185     sys.exit(pytest.main(args))