j3s.sh
1#!/bin/sh -e
2#
3# ip-dhcp-host.sh - add or remove a mac address --> ipv4 mapping
4
5action="$1"
6network_name="$2"
7mac_address="$3"
8ipv4_address="$4"
9
10[ "$action" != 'add' ] && [ "$action" != 'delete' ] && printf 'you must set $action to either add or delete (1st arg)\n' && exit 1
11[ "$network_name" = '' ] && printf 'you must set $network_name (2nd arg)\n' && exit 1
12[ "$mac_address" = '' ] && printf 'you must set $mac_address (3rd arg)\n' && exit 1
13[ "$ipv4_address" = '' ] && printf 'you must set $ipv4_address (4th arg)\n' && exit 1
14
15# for some reason libvirt appears to remember every dhcp lease even after it has expired.
16# adding a new ip-dhcp-host will fail if there already is one with the same ip address.
17# so we will try to delete any that already exist with that IP address just in case!
18if [ "$action" = 'add' ]; then
19 printf "trying to delete any existing (probably expired) dhcp associations for $ipv4_address..."
20 virsh net-update "$network_name" delete ip-dhcp-host "<host ip='$ipv4_address' />" --live --config || true
21
22 printf "adding $mac_address --> $ipv4_address to $network_name"
23 virsh net-update "$network_name" "$action" ip-dhcp-host "<host mac='$mac_address' ip='$ipv4_address' />" --live --config
24else
25 printf "removing $mac_address and $ipv4_address from $network_name if they exist"
26 virsh net-update "$network_name" "$action" ip-dhcp-host "<host mac='$mac_address' />" --live --config || true
27 virsh net-update "$network_name" "$action" ip-dhcp-host "<host ip='$ipv4_address' />" --live --config || true
28fi
29
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31