Added utility to restart kubernetes DNS.

This is necessary after a system restart if the api server's IP address changed.

continuousintegration/buildtree_runner/vmBootstrap/restartKubeDNS.sh

+#!/bin/bash -e
+
+echo Removing kubernetes DNS...
+
+sudo kubectl delete ns kube-system || true
+
+echo -n Waiting kubernetes DNS termination
+while (kubectl get ns kube-system  2> /dev/null > /dev/null); do echo -n .; sleep 1; done ; echo Done...
+
+echo Setting up kubernetes DNS...
+dns_clusterip='10.254.199.254'
+#dns_domainname=`hostname -d`
+dns_domainname=cluster.local
+docker_ipaddress=`ifconfig docker0  | perl -e 'while(<>) { if (/inet\s+(\S+)\s/) { print $1."\n"; } }'`
+sudo systemctl stop firewalld
+sudo systemctl disable firewalld
+#my_ipaddress=127.0.0.1
+upper_level_dns=`perl -e 'while (<>) { if ($_=~ /nameserver (.*)/) { print $1."\n"; exit }}' < /etc/resolv.conf`
+
+echo dns_clusterip=${dns_clusterip}
+echo dns_domainname=${dns_domainname}
+echo docker_ipaddress=${docker_ipaddress}
+echo upper_level_dns=${upper_level_dns}
+
+dnspoddir=$(mktemp -d)
+cp kubernetes/dns-svc.yaml kubernetes/pod-dns.yaml ${dnspoddir}
+
+perl -p -i -e 's/<%= \@dns_clusterip -%>/'"${dns_clusterip}"'/' ${dnspoddir}/dns-svc.yaml
+
+perl -p -i -e 's/<%= \@dns_domainname -%>/'"${dns_domainname}"'/' ${dnspoddir}/pod-dns.yaml
+perl -p -i -e 's/<%= \@my_ipaddress -%>/'"${docker_ipaddress}"'/' ${dnspoddir}/pod-dns.yaml
+perl -p -i -e 's/<%= \@upper_level_dns -%>/'"${upper_level_dns}"'/' ${dnspoddir}/pod-dns.yaml
+
+sudo kubectl create -f kubernetes/kube-system_ns.yaml || true
+sudo kubectl create -f ${dnspoddir}/dns-svc.yaml
+sudo kubectl create -f ${dnspoddir}/pod-dns.yaml
+
+rm -rf ${dnspoddir}
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