tachang · April 10, 2015 19:37 · Apr 10, 2015
diff --git a/network-restart.sh b/network-restart.sh
@@ -0,0 +1,58 @@
+#!/bin/bash
+#
+# Yury V. Zaytsev <[email protected]> (C) 2011
+#
+# This work is herewith placed in public domain.
+#
+# Use this script to cleanly restart the default libvirt network after its
+# definition have been changed (e.g. added new static MAC+IP mappings) in order
+# for the changes to take effect. Restarting the network alone, however, causes
+# the guests to lose connectivity with the host until their network interfaces
+# are re-attached.
+#
+# The script re-attaches the interfaces by obtaining the information about them
+# from the current libvirt definitions. It has the following dependencies:
+#
+#   - virsh (obviously)
+#   - tail / head / grep / awk / cut
+#   - XML::XPath (e.g. perl-XML-XPath package)
+#
+# Note that it assumes that the guests have exactly 1 NAC each attached to the
+# given network! Extensions to account for more (or none) interfaces etc. are,
+# of course, most welcome.
+#
+# ZYV
+#
+
+set -e
+set -u
+
+NETWORK_NAME=default
+NETWORK_HOOK=/etc/libvirt/hooks/qemu
+
+#virsh net-define /opt/config/libvirt/network-$NETWORK_NAME.xml
+virsh net-destroy $NETWORK_NAME
+virsh net-start $NETWORK_NAME
+
+MACHINES=$( virsh list | tail -n +3 | head -n -1 | awk '{ print $2; }' )
+
+for m in $MACHINES ; do
+
+    echo "$m"
+    MACHINE_INFO=$( virsh dumpxml "$m" | xpath -e /domain/devices/interface[1] 2> /dev/null )
+
+    echo "$MACHINE_INFO"
+    MACHINE_MAC=$( echo "$MACHINE_INFO" | grep "mac address" | cut -d '"' -f 2 )
+
+    echo "$MACHINE_MAC"
+    MACHINE_MOD=$( echo "$MACHINE_INFO" | grep "model type" | cut -d '"' -f 2 )
+
+    set +e
+    virsh detach-interface "$m" network --mac "$MACHINE_MAC" && sleep 3
+    virsh attach-interface "$m" network $NETWORK_NAME --mac "$MACHINE_MAC" --model "$MACHINE_MOD"
+    set -e
+
+    #$NETWORK_HOOK "$m" stopped && sleep 3
+    #$NETWORK_HOOK "$m" start
+
+done