refactor(docker): moved connectivity helpers for docker compose scena…

…rios to bash helper lib

tests/docker/scenarios/libnetemhelper.sh

@@ -0,0 +1,42 @@
+DOCKERCMD=docker
+# use podman if available
+if command -v podman &> /dev/null; then
+  DOCKERCMD=podman
+fi
+
+set_on_all_interfaces() {
+  for n in $NODES; do
+    IFACES=$($DOCKERCMD exec $n cat /proc/net/dev | awk '{print $1}' | grep -E '^eth[0-9]+' | cut -d ':' -f1)
+    CMDS=""
+    for i in $IFACES; do
+      CMDS="$CMDS  echo \"[$1] Setting loss on $n ($i) to $2\" && tc qdisc $1 dev $i root netem loss $2 && "	
+    done
+    $DOCKERCMD exec $n bash -c "${CMDS} true"
+  done
+}
+
+set_on_all_interfaces add 0%
+
+
+set_loss () {
+  echo "Setting loss on $1 to $2"
+  $DOCKERCMD exec $1 tc qdisc change dev eth0 root netem loss $2
+}
+
+loss_interval() {
+  IFACE=eth0
+  if [ -n "$4" ]; then
+    IFACE=$4
+  fi
+  echo "Setting loss on $1 ($IFACE) to $2 for $3s"
+  $DOCKERCMD exec $1 tc qdisc change dev $IFACE root netem loss $2
+  sleep $3
+  $DOCKERCMD exec $1 tc qdisc change dev $IFACE root netem loss 0%
+}
+
+cleanup () {
+  echo "Cleaning up..."
+  set_on_all_interfaces del 0%
+}
+
+trap cleanup EXIT

tests/docker/scenarios/line-3n-loss.sh

@@ -1,33 +1,12 @@
 #!/bin/bash
 
-DOCKERCMD=docker
-# use podman if available
-if command -v podman &> /dev/null; then
-  DOCKERCMD=podman
-fi
-$DOCKERCMD exec line-3n-n1-1 tc qdisc add dev eth0 root netem loss 0%
-$DOCKERCMD exec line-3n-n2-1 tc qdisc add dev eth0 root netem loss 0%
-$DOCKERCMD exec line-3n-n3-1 tc qdisc add dev eth0 root netem loss 0%
+NODES="line-3n-n1-1 line-3n-n2-1 line-3n-n3-1"
 
-cleanup () {
-  echo "Cleaning up..."
-  $DOCKERCMD exec line-3n-n1-1 tc qdisc del dev eth0 root netem loss 0%
-  $DOCKERCMD exec line-3n-n2-1 tc qdisc del dev eth0 root netem loss 0%
-  $DOCKERCMD exec line-3n-n3-1 tc qdisc del dev eth0 root netem loss 0%
-}
-
-trap cleanup EXIT
+# Remember: define list of NODES before loading the helper functions
+. $(dirname $0)/libnetemhelper.sh
 
 
 while true; do
-  echo "Setting loss on n3 to 100% for 30s" 
-  $DOCKERCMD exec line-3n-n3-1 tc qdisc change dev eth0 root netem loss 100%
-  sleep 30
-  echo " n3 back to 0% loss." 
-  $DOCKERCMD exec line-3n-n3-1 tc qdisc change dev eth0 root netem loss 0%
-  echo "Setting loss on n1 to 100% for 30s"	
-  $DOCKERCMD exec line-3n-n1-1 tc qdisc change dev eth0 root netem loss 100%
-  sleep 30
-  echo " n1 back to 0% loss."
-  $DOCKERCMD exec line-3n-n1-1 tc qdisc change dev eth0 root netem loss 0%
+  loss_interval line-3n-n1-1 100% 30
+  loss_interval line-3n-n3-1 100% 30
 done