From 0d61cacb08af76312b10640259e062ee8b671532 Mon Sep 17 00:00:00 2001
From: Thomas Eizinger <thomas@eizinger.io>
Date: Thu, 2 Oct 2025 05:27:05 +0000
Subject: [PATCH] ci: add 20% jitter in test environment (#10504)

To simulate the real-world more accurately, we add a 20% jitter to the
specified latency on the router containers.
---
 scripts/router/router.sh | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/scripts/router/router.sh b/scripts/router/router.sh
index 8731e85bb..c3f1851e6 100644
--- a/scripts/router/router.sh
+++ b/scripts/router/router.sh
@@ -67,9 +67,10 @@ fi
 # Add configurable latency if specified
 if [ -n "${NETWORK_LATENCY_MS:-}" ]; then
     LATENCY=$((NETWORK_LATENCY_MS / 2)) # Latency is only applied to outbound packets. To achieve the actual configured latency, we apply half of it to each interface.
+    JITTER=$((LATENCY / 5))             # Vary latency by 20%
 
-    tc qdisc add dev internet root netem delay "${LATENCY}ms"
-    tc qdisc add dev internal root netem delay "${LATENCY}ms"
+    tc qdisc add dev internet root netem delay "${LATENCY}ms" "${JITTER}ms"
+    tc qdisc add dev internal root netem delay "${LATENCY}ms" "${JITTER}ms"
 fi
 
 echo "-----------------------------------------------------------------------------------------------"