On OpenShift see https://access.redhat.com/solutions/7070905
We are going to be adding a host alias for example.com in this example by adding the following to the coredns configmap:
Code Block |
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hosts custom.hosts example.com {
1.2.3.4 example.com
fallthrough
} |
For multiple hosts
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hosts custom.hosts example.com test.com {
1.2.3.4 example.com
6.6.6.6 test.com
fallthrough
} |
Start by editing the coredns configmap:
Code Block |
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kubectl -n kube-system edit configmap/coredns |
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apiVersion: v1
data:
Corefile: |
.:53 {
errors
health {
lameduck 5s
}
ready
kubernetes cluster.local in-addr.arpa ip6.arpa {
pods insecure
fallthrough in-addr.arpa ip6.arpa
ttl 30
}
prometheus :9153
forward . /etc/resolv.conf {
max_concurrent 1000
}
cache 30
loop
reload
loadbalance
hosts custom.hosts example.com test.com {
1.2.3.4 example.com
6.6.6.6 test.com
fallthrough
}
} |
Force CoreDNS to reload the ConfigMap by entering:
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kubectl delete pod --namespace kube-system -l k8s-app=kube-dns |
Performing an nslookup from a pod should show the new IP address for example.com
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root@ssh-server-5bd5774cf7-fgvt4:/# nslookup example.com
Server: 10.96.0.10
Address: 10.96.0.10#53
Name: example.com
Address: 1.2.3.4 |
References