Network Manager suports starting dnsmasq which helps you have a local cache for DNS thus getting faster resolution for the DNS queries.

Dnsmasq with netowrkmanager

So, one thing that I have been thinking about is having a local name resolution for the VMs. So, I wanted something like this to work:

vm1 => 172.17.42,1

vm2 => 172.17.42,2

and so on …

To achieve this and reverse dns to work, we will add the entries in file “/etc/NetworkManager/dnsmasq.d/hostnames“. Just one more problem, adding so many entries manually? So, to help you with that, I created this small script:

#!/bin/bash -
#===============================================================================
#
#          FILE: add-dnsmasq.sh
#
#         USAGE: ./add-dnsmasq.sh
#
#   DESCRIPTION:
#
#       OPTIONS: ---
#  REQUIREMENTS: ---
#          BUGS: ---
#         NOTES: ---
#        AUTHOR: Amit Agarwal (aka), 
#  ORGANIZATION: 
#      REVISION:  ---
#===============================================================================

IPPRE='172.17.42.'
for i in {1..250}
do
    echo "address=/vm$i/$IPPRE$i" >> /etc/NetworkManager/dnsmasq.d/hostnames
    echo "ptr-record=vm$i,$IPPRE$i" >> /etc/NetworkManager/dnsmasq.d/hostnames
done

Just run this script to add all the entries and restart dnsmasq by killing the already running instance. 🙂

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