topotests: isis-tilfa add a switchover test after BFD down

Add a switchover test that consists in:
- Setting up ISIS BFD between rt5 and rt6
- Setting no link-detect on rt6 eth-rt5 so that zebra does not take
  account linkdown events on this interface.
- Shutting down rt6 eth-rt5 from the switch side

Check that the switchover between primary and backup happens before the
SPF re-computation.

Signed-off-by: Louis Scalbert <louis.scalbert@6wind.com>

3 files changed, 233 insertions, 2 deletions

diff --git a/tests/topotests/isis_tilfa_topo1/rt5/bfdd.conf b/tests/topotests/isis_tilfa_topo1/rt5/bfdd.conf
new file mode 100644
index 0000000000..d27625ff35
--- /dev/null
+++ b/tests/topotests/isis_tilfa_topo1/rt5/bfdd.conf
@@ -0,0 +1,14 @@
+hostname rt5
+!
+#debug bfd network
+#debug bfd peer
+#debug bfd zebra
+!
+bfd
+ peer 10.0.8.6 interface eth-rt6
+  detect-multiplier 3
+  receive-interval 300
+  transmit-interval 300
+  no shutdown
+ !
+!
\ No newline at end of file
diff --git a/tests/topotests/isis_tilfa_topo1/rt6/bfdd.conf b/tests/topotests/isis_tilfa_topo1/rt6/bfdd.conf
new file mode 100644
index 0000000000..0c8ba7268c
--- /dev/null
+++ b/tests/topotests/isis_tilfa_topo1/rt6/bfdd.conf
@@ -0,0 +1,14 @@
+hostname rt6
+!
+#debug bfd network
+#debug bfd peer
+#debug bfd zebra
+!
+bfd
+ peer 10.0.8.5 interface eth-rt5
+  detect-multiplier 3
+  receive-interval 300
+  transmit-interval 300
+  no shutdown
+ !
+!
\ No newline at end of file
diff --git a/tests/topotests/isis_tilfa_topo1/test_isis_tilfa_topo1.py b/tests/topotests/isis_tilfa_topo1/test_isis_tilfa_topo1.py
index 171a36d3e7..3f34a87793 100755
--- a/tests/topotests/isis_tilfa_topo1/test_isis_tilfa_topo1.py
+++ b/tests/topotests/isis_tilfa_topo1/test_isis_tilfa_topo1.py
@@ -188,6 +188,9 @@ def setup_module(mod):
         router.load_config(
             TopoRouter.RD_ISIS, os.path.join(CWD, "{}/isisd.conf".format(rname))
         )
+        router.load_config(
+            TopoRouter.RD_BFD, os.path.join(CWD, "/dev/null".format(rname))
+        )
 
     tgen.start_router()
 
@@ -200,7 +203,7 @@ def teardown_module(mod):
     tgen.stop_topology()
 
 
-def router_compare_json_output(rname, command, reference, count=120):
+def router_compare_json_output(rname, command, reference, count=120, wait=0.5):
     "Compare router JSON output"
 
     logger.info('Comparing router "%s" "%s" output', rname, command)
@@ -210,7 +213,7 @@ def router_compare_json_output(rname, command, reference, count=120):
 
     # Run test function until we get an result. Wait at most 60 seconds.
     test_func = partial(topotest.router_json_cmp, tgen.gears[rname], command, expected)
-    _, diff = topotest.run_and_expect(test_func, None, count=count, wait=0.5)
+    _, diff = topotest.run_and_expect(test_func, None, count=count, wait=wait)
     assertmsg = '"{}" JSON output mismatches the expected result'.format(rname)
     assert diff is None, assertmsg
 
@@ -901,6 +904,206 @@ def test_mpls_lib_step12():
         )
 
 
+#
+# Step 13
+#
+# Action(s):
+# - shut / unshut a rt6 interface
+# - Setup BFD
+#
+# Expected changes:
+# - All route tables go back to previous state situation
+# - At the end of test, next SPF is scheduled in approximatively 15s
+#
+def test_rib_ipv4_step13():
+    logger.info("Test (step 13): verify IPv4 RIB")
+    tgen = get_topogen()
+
+    # Skip if previous fatal error condition is raised
+    if tgen.routers_have_failure():
+        pytest.skip(tgen.errors)
+
+    logger.info("Unsetting spf-delay-ietf init-delay of 15s")
+    tgen.net["rt6"].cmd('vtysh -c "conf t" -c "router isis 1" -c "no spf-delay-ietf"')
+
+    logger.info(
+        "Unshut the rt6 interface to rt5 from the switch side and check fast-reroute"
+    )
+    tgen.net.cmd_raises("ip link set %s up" % tgen.net["s8"].intfs[1])
+
+    logger.info("Setup BFD on rt5 and rt6")
+    for rname in ["rt5", "rt6"]:
+        conf_file = os.path.join(CWD, "{}/bfdd.conf".format(rname))
+        tgen.net[rname].cmd("vtysh -f {}".format(conf_file))
+
+    expect = (
+        '[{"multihop":false,"peer":"10.0.8.5","interface":"eth-rt5","status":"up"}]'
+    )
+    router_compare_json_output("rt6", "show bfd peers json", expect)
+
+    logger.info("Unset link-detect on rt6 eth-rt5")
+    # Unset link detection. We want zebra to consider linkdow as operationaly up
+    # in order that BFD triggers LFA instead of the interface down
+    tgen.net["rt6"].cmd('vtysh -c "conf t" -c "int eth-rt5" -c "no link-detect"')
+
+    # reset spf-interval
+    logger.info("Shut/unshut a rt6 eth-rt5 interface and set spf-interval to 15s")
+    tgen.net["rt6"].cmd(
+        'vtysh -c "conf t" -c "router isis 1" -c "spf-delay-ietf init-delay 15000 short-delay 0 long-delay 0 holddown 0 time-to-learn 0"'
+    )
+
+    for rname in ["rt1", "rt2", "rt3", "rt4", "rt5", "rt6"]:
+        router_compare_json_output(
+            rname, "show ip route isis json", outputs[rname][10]["show_ip_route.ref"]
+        )
+
+    logger.info("Set ISIS BFD")
+    tgen.net["rt5"].cmd('vtysh -c "conf t" -c "int eth-rt6" -c "isis bfd"')
+    tgen.net["rt6"].cmd('vtysh -c "conf t" -c "int eth-rt5" -c "isis bfd"')
+
+
+def test_rib_ipv6_step13():
+    logger.info("Test (step 13): verify IPv6 RIB")
+    tgen = get_topogen()
+
+    # Skip if previous fatal error condition is raised
+    if tgen.routers_have_failure():
+        pytest.skip(tgen.errors)
+
+    for rname in ["rt1", "rt2", "rt3", "rt4", "rt5", "rt6"]:
+        router_compare_json_output(
+            rname,
+            "show ipv6 route isis json",
+            outputs[rname][10]["show_ipv6_route.ref"],
+        )
+
+
+def test_mpls_lib_step13():
+    logger.info("Test (step 13): verify MPLS LIB")
+    tgen = get_topogen()
+
+    # Skip if previous fatal error condition is raised
+    if tgen.routers_have_failure():
+        pytest.skip(tgen.errors)
+
+    for rname in ["rt1", "rt2", "rt3", "rt4", "rt5", "rt6"]:
+        router_compare_json_output(
+            rname, "show mpls table json", outputs[rname][10]["show_mpls_table.ref"]
+        )
+
+
+#
+# Step 14
+#
+# Action(s):
+# - shut the eth-rt5 interface on rt6
+#
+# Expected changes:
+# - Route switchover of routes via eth-rt5
+#
+def test_rt6_step14():
+    logger.info("Test (step 14): verify IPv4/6 RIB and MPLS table")
+    tgen = get_topogen()
+
+    # Skip if previous fatal error condition is raised
+    if tgen.routers_have_failure():
+        pytest.skip(tgen.errors)
+
+    logger.info(
+        "Shut a rt6 interface to rt5 from the switch side and check fast-reroute"
+    )
+    tgen.net.cmd_raises("ip link set %s down" % tgen.net["s8"].intfs[1])
+
+    rname = "rt6"
+
+    expect = (
+        '[{"multihop":false,"peer":"10.0.8.5","interface":"eth-rt5","status":"down"}]'
+    )
+    router_compare_json_output(
+        rname,
+        "show bfd peers json",
+        expect,
+        count=20,
+        wait=0.05,
+    )
+
+    router_compare_json_output(
+        rname,
+        "show ip route isis json",
+        outputs[rname][11]["show_ip_route.ref"],
+        count=1,
+    )
+    router_compare_json_output(
+        rname,
+        "show ipv6 route isis json",
+        outputs[rname][11]["show_ipv6_route.ref"],
+        count=1,
+    )
+    router_compare_json_output(
+        rname,
+        "show mpls table json",
+        outputs[rname][11]["show_mpls_table.ref"],
+        count=1,
+    )
+
+
+#
+# Step 15
+#
+# Action(s): wait for the convergence and SPF computation on rt6
+#
+# Expected changes:
+# - convergence of IPv4/6 RIB and MPLS table
+#
+def test_rib_ipv4_step15():
+    logger.info("Test (step 15): verify IPv4 RIB")
+    tgen = get_topogen()
+
+    # Skip if previous fatal error condition is raised
+    if tgen.routers_have_failure():
+        pytest.skip(tgen.errors)
+
+    logger.info("Check SPF convergence")
+    for rname in ["rt1", "rt2", "rt3", "rt4", "rt5", "rt6"]:
+        router_compare_json_output(
+            rname,
+            "show ip route isis json",
+            outputs[rname][12]["show_ip_route.ref"],
+        )
+
+
+def test_rib_ipv6_step15():
+    logger.info("Test (step 15): verify IPv6 RIB")
+    tgen = get_topogen()
+
+    # Skip if previous fatal error condition is raised
+    if tgen.routers_have_failure():
+        pytest.skip(tgen.errors)
+
+    for rname in ["rt1", "rt2", "rt3", "rt4", "rt5", "rt6"]:
+        router_compare_json_output(
+            rname,
+            "show ipv6 route isis json",
+            outputs[rname][12]["show_ipv6_route.ref"],
+        )
+
+
+def test_mpls_lib_step15():
+    logger.info("Test (step 15): verify MPLS LIB")
+    tgen = get_topogen()
+
+    # Skip if previous fatal error condition is raised
+    if tgen.routers_have_failure():
+        pytest.skip(tgen.errors)
+
+    for rname in ["rt1", "rt2", "rt3", "rt4", "rt5", "rt6"]:
+        router_compare_json_output(
+            rname,
+            "show mpls table json",
+            outputs[rname][12]["show_mpls_table.ref"],
+        )
+
+
 # Memory leak test template
 def test_memory_leak():
     "Run the memory leak test and report results."