OpenShift 3 manually adding NetworkManager DNSMASQ dispatcher script

Environment

• Openshift Container Platform 3.x

Issue

• OpenShift node using dnsmasq is not forwarding queries to my DNS servers.
• The file /etc/NetworkManager/dispatcher.d/99-origin-dns.sh is not on my OpenShift node.

Resolution

In OpenShift 3.2 This page is not included, but the link has been rewritten to point to the nearest parent document.DNSMASQ was introduced.

• By default, new nodes installed with OpenShift Enterprise 3.2 will have Dnsmasq installed and configured as the default nameserver for both the host and pods.

• A network dispatacher script is run to configure the host with the correct resolv.conf and dnsmasq configurations so that DNS queires forward correctly.

• If this script is not present or is out dated it can be manually updated.

# yum install openshift-ansible-roles-3.2*
# cp /usr/share/ansible/openshift-ansible/roles/openshift_node_dnsmasq/files/networkmanager/99-origin-dns.sh /etc/NetworkManager/dispatcher.d/99-origin-dns.sh
# systemctl restart NetworkManager 

• Check and make sure the dnsmasq is configured with your external DNS servers.

  # cat /etc/dnsmasq.d/origin-upstream-dns.conf

• If the DNS name servers are not correct or configured. Make sure they correct in NetworkManager.

  nmcli connection show eth0 | grep "ipv4.dns"

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