diff options
Diffstat (limited to 'roles/openshift_node_dnsmasq/files/networkmanager/99-origin-dns.sh')
-rwxr-xr-x | roles/openshift_node_dnsmasq/files/networkmanager/99-origin-dns.sh | 62 |
1 files changed, 62 insertions, 0 deletions
diff --git a/roles/openshift_node_dnsmasq/files/networkmanager/99-origin-dns.sh b/roles/openshift_node_dnsmasq/files/networkmanager/99-origin-dns.sh new file mode 100755 index 000000000..5a187710b --- /dev/null +++ b/roles/openshift_node_dnsmasq/files/networkmanager/99-origin-dns.sh @@ -0,0 +1,62 @@ +#!/bin/bash -x + +# This NetworkManager dispatcher script replicates the functionality of +# NetworkManager's dns=dnsmasq however, rather than hardcoding the listening +# address and /etc/resolv.conf to 127.0.0.1 it pulls the IP address from the +# interface that owns the default route. This enables us to then configure pods +# to use this IP address as their only resolver, where as using 127.0.0.1 inside +# a pod would fail. +# +# To use this, +# - If this host is also a master, reconfigure master dnsConfig to listen on +# 8053 to avoid conflicts on port 53 and open port 8053 in the firewall +# - Drop this script in /etc/NetworkManager/dispatcher.d/ +# - systemctl restart NetworkManager +# - Configure node-config.yaml to set dnsIP: to the ip address of this +# node +# +# Test it: +# host kubernetes.default.svc.cluster.local +# host google.com +# +# TODO: I think this would be easy to add as a config option in NetworkManager +# natively, look at hacking that up + +cd /etc/sysconfig/network-scripts +. ./network-functions + +[ -f ../network ] && . ../network + +if [[ $2 =~ ^(up|dhcp4-change)$ ]]; then + # couldn't find an existing method to determine if the interface owns the + # default route + def_route=$(/sbin/ip route list match 0.0.0.0/0 | awk '{print $3 }') + def_route_int=$(/sbin/ip route get to ${def_route} | awk '{print $3}') + def_route_ip=$(/sbin/ip route get to ${def_route} | awk '{print $5}') + if [[ ${DEVICE_IFACE} == ${def_route_int} && \ + -n "${IP4_NAMESERVERS}" ]]; then + if [ ! -f /etc/dnsmasq.d/origin-dns.conf ]; then + cat << EOF > /etc/dnsmasq.d/origin-dns.conf +strict-order +no-resolv +domain-needed +server=/cluster.local/172.30.0.1 +server=/30.172.in-addr.arpa/172.30.0.1 +EOF + fi + # zero out our upstream servers list and feed it into dnsmasq + echo -n > /etc/dnsmasq.d/origin-upstream-dns.conf + for ns in ${IP4_NAMESERVERS}; do + if [[ ! -z $ns ]]; then + echo "server=${ns}" >> /etc/dnsmasq.d/origin-upstream-dns.conf + fi + done + systemctl restart dnsmasq + + sed -i '0,/^nameserver/ s/^nameserver.*$/nameserver '"${def_route_ip}"'/g' /etc/resolv.conf + + if ! grep -q '99-origin-dns.sh' /etc/resolv.conf; then + echo "# nameserver updated by /etc/NetworkManager/dispatcher.d/99-origin-dns.sh" >> /etc/resolv.conf + fi + fi +fi |