smoke: make nexthop ageing test more robust on slow machines

The nexthop ageing smoke test could fail intermittently on slow or heavily
loaded machines, where state transitions (like nexthop reachability or
ageing) take slightly longer than expected.

This patch introduces a check_nexthop() helper that polls grcli show ip
nexthop for up to 5 seconds, instead of assuming an immediate state
change. This ensures that the test is tolerant to minor delays without
compromising on correctness.

Signed-off-by: Maxime Leroy <[email protected]>

Author: maxime-leroy

smoke/nexthop_ageing_test.sh

@@ -4,6 +4,27 @@
 
 . $(dirname $0)/_init.sh
 
+check_nexthop() {
+	local ip="$1"
+	local expect_reacheable="$2"
+	local timeout=5
+	for i in $(seq 1 $timeout); do
+		grcli show ip nexthop | grep -qE "$ip.+reachable";
+		local result=$?
+
+		if [ "$expect_reacheable" = "true" ] && [ "$result" -eq 0 ]; then
+			return 0
+		fi
+		if [ "$expect_reacheable" = "false" ] && [ "$result" -ne 0 ]; then
+			return 0
+		fi
+
+		sleep 1
+	done
+
+	return 1
+}
+
 p0=${run_id}0
 p1=${run_id}1
 
@@ -38,8 +59,9 @@ show ip address
 EOF
 
 # ensure that nexthops are still reachable
-grcli show ip nexthop | grep -E '172\.16\.0\.2.+reachable' || fail "nexthop should be reachable"
-grcli show ip nexthop | grep -E '172\.16\.1\.2.+reachable' || fail "nexthop should be reachable"
+check_nexthop '172\.16\.0\.2' true || fail "nexthop 172.16.0.2 should be reachable"
+check_nexthop '172\.16\.1\.2' true || fail "nexthop 172.16.1.2 should be reachable"
+
 # ensure addresses were not destroyed
 grcli show ip address | grep -E "^$p0[[:space:]]+172\\.16\\.0\\.1/24$" || fail "addresses were destroyed"
 grcli show ip address | grep -E "^$p1[[:space:]]+172\\.16\\.1\\.1/24$" || fail "addresses were destroyed"
@@ -52,8 +74,9 @@ ip -n $p1 link set $p1 down
 sleep 3
 
 # ensure that nexthops have been aged out and destroyed
-! grcli show ip nexthop | grep -q '172\.16\.0\.2.*reachable' || fail "nexthop should be destroyed"
-! grcli show ip nexthop | grep -q '172\.16\.1\.2.*reachable' || fail "nexthop should be destroyed"
+check_nexthop '172\.16\.0\.2' false || fail "nexthop 172.16.0.2 should be destroyed"
+check_nexthop '172\.16\.1\.2' false || fail "nexthop 172.16.1.2 should be destroyed"
+
 # ensure addresses were not destroyed
 grcli show ip address | grep -E "^$p0[[:space:]]+172\\.16\\.0\\.1/24$" || fail "addresses were destroyed"
 grcli show ip address | grep -E "^$p1[[:space:]]+172\\.16\\.1\\.1/24$" || fail "addresses were destroyed"