Network Manager Dispatcher

This script modifies the system DNS resolver to prioritize pointing to the dnsmasq service (configured later). This ensures that virtual machines can resolve the various domains, routes, and registries required for the different steps of the process.

To enable this, you need to create a script named forcedns in /etc/NetworkManager/dispatcher.d/ with the following content:

Note

Please ensure you modify the appropriate fields to align with your laboratory environment.

#!/bin/bash

export IP="192.168.125.1"
export BASE_RESOLV_CONF="/run/NetworkManager/resolv.conf"

if ! [[ `grep -q "$IP" /etc/resolv.conf` ]]; then
export TMP_FILE=$(mktemp /etc/forcedns_resolv.conf.XXXXXX)
cp $BASE_RESOLV_CONF $TMP_FILE
chmod --reference=$BASE_RESOLV_CONF $TMP_FILE
sed -i -e "s/hypershiftbm.lab//" -e "s/search /& hypershiftbm.lab /" -e "0,/nameserver/s/nameserver/& $IP\n&/" $TMP_FILE
mv $TMP_FILE /etc/resolv.conf
fi
echo "ok"

#!/bin/bash

export IP="2620:52:0:1306::1"
export BASE_RESOLV_CONF="/run/NetworkManager/resolv.conf"

if ! [[ `grep -q "$IP" /etc/resolv.conf` ]]; then
export TMP_FILE=$(mktemp /etc/forcedns_resolv.conf.XXXXXX)
cp $BASE_RESOLV_CONF $TMP_FILE
chmod --reference=$BASE_RESOLV_CONF $TMP_FILE
sed -i -e "s/hypershiftbm.lab//" -e "s/search /& hypershiftbm.lab /" -e "0,/nameserver/s/nameserver/& $IP\n&/" $TMP_FILE
mv $TMP_FILE /etc/resolv.conf
fi
echo "ok"

#!/bin/bash

export IP="192.168.126.1"
export BASE_RESOLV_CONF="/run/NetworkManager/resolv.conf"

if ! [[ `grep -q "$IP" /etc/resolv.conf` ]]; then
export TMP_FILE=$(mktemp /etc/forcedns_resolv.conf.XXXXXX)
cp $BASE_RESOLV_CONF $TMP_FILE
chmod --reference=$BASE_RESOLV_CONF $TMP_FILE
sed -i -e "s/hypershiftbm.lab//" -e "s/search /& hypershiftbm.lab /" -e "0,/nameserver/s/nameserver/& $IP\n&/" $TMP_FILE
mv $TMP_FILE /etc/resolv.conf
fi
echo "ok"

The IP variable at the beginning of the script must be modified to point to the IP address of the Hypervisor's interface hosting the Openshift management cluster.

After creating the file, you need to add execution permissions using the command:

chmod 755 /etc/NetworkManager/dispatcher.d/forcedns

Then, execute it once. The output should indicate ok.