[Freeipa-users] FreeIPA and DHCP

[Jochen Hein]

William Brown <wibrown-H+wXaHxf7aLQT0dZR+AlfA at public.gmane.org> writes:

> On Fri, 2015-10-16 at 15:01 +0200, Nicola Canepa wrote:
>> Hello.
>> Is there a suggested way to have DHCP IP/MAC associations managed 
>> through the IPA web interface?
>
> There is currently no way to manage DHCP with FreeIPA.

Freeipa hosts do have MAC values as a field and there is an IP address
assigned.  I've found a script to extract the info for isc DHCP at
http://lesloueizeh.com/jdieter/freeipa-dhcpd/generate_dhcp.py

I've implemented a script for using with dnsmasq:

-------------- cut here -------------------------
#!/bin/bash

out=/etc/dnsmasq.d/dynamic-hosts.conf
#out=/tmp/xxx
tmp=/etc/dnsmasq.d/dynamic-hosts.conf.tmp

KRBPRINC='host/echidna.jochen.org at JOCHEN.ORG'

kinit -k $KRBPRINC

cat > $tmp <<EOF
# This file has all hosts with their MAC and IP addresses.
# It is created by the cron job /root/scripts/update-dhcp-hosts-from-ipa.sh
# and reads host/mac/ip from freeipa.
EOF
LC_ALL=C ipa host-find --all | awk '
	/MAC address:/ { for(i=3;i<=NF;i++){mac_address=mac_address $i};  }
	/Class: vpnclient/ { tag="set:vpnclient," }
	/serverhostname:/ { 
		if ( mac_address != "" )
			print mac_address " " $2 " " tag ; tag=""; mac_address="" }' | \
	while read mac_address host tag; do
		mac_address=$(echo $mac_address | tr 'A-Z' 'a-z')
		ip=$(getent ahostsv4 $host | head -n 1 | cut -f1 -d ' ' )
		echo "dhcp-host=$mac_address,$tag$ip,$host"
	done | sort >> $tmp

if cmp -s $out $tmp; then
	rm -f $tmp
else
	mv $tmp $out
	systemctl restart dnsmasq.service
fi

kdestroy

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Jochen


-- 
The only problem with troubleshooting is that the trouble shoots back.