restart-virsh-networking.sh

#!/bin/bash
# Based on public domain work by Yury V. Zaytsev <[email protected]>
# Deps: bash4+, xpath, egrep, virsh

set -e
set -u

MACHINES=$( virsh list --name | egrep "\S" )
NETWORK="default"
BRIDGE="bridge0"
DRYRUN="${DRYRUN:-echo}"

$DRYRUN virsh net-destroy $NETWORK
$DRYRUN virsh net-start $NETWORK

declare -A MACS
declare -A TYPES

#Create array
for m in $MACHINES ; do
     #MACHINE_INFO=$( virsh dumpxml --inactive "$m" ) is useful if you encounter errors
     MACHINE_INFO=$( virsh dumpxml "$m" )
     eval $(echo $MACHINE_INFO | xpath "/domain/devices/interface[@type='bridge']/mac/@address")
     eval $(echo $MACHINE_INFO | xpath "/domain/devices/interface[@type='bridge']/model/@type")
     MACS[$m]=$address
     TYPES[$m]=$type
     echo "machine $m network bridge $type mac $address"
done

#Could consider running all these in the background/parallely .. not sure how safe that is so not doing so currently
#set +e/-e also copied from previous script -- better error handling would be ideal for a production quality script
for m in $MACHINES ; do
     set +e
     $DRYRUN virsh detach-interface --domain "$m" --mac "${MACS[$m]}" --type bridge
     set -e
done

#Taken from previous script as 3s downtime was not a problem for my scenarios and I did not test anything else
#sleep 3

#Same as previous loop re: background/set
for m in $MACHINES; do
     set +e
     $DRYRUN virsh attach-interface --domain "$m" --type bridge --source $BRIDGE --mac "${MACS[$m]}" --model "${TYPES[$m]}"
     set -e
done