CODEWITHSUNDEEP
kubernetes
David Tinker
David Tinker

Reputation: 9644

Kubernetes access to port on node from inside pod?

I am trying to access a service listening on a port running on every node in my bare metal (Ubuntu 20.04) cluster from inside a pod. I can use the real IP address of one of the nodes and it works. However I need pods to connect to the port on their own node. I cant use '127.0.0.1' inside a pod.

More info: I am trying to wrangle a bunch of existing services into k8s. We use an old version of Consul for service discovery and have it running on every node providing DNS on 8600. I figured out how to edit the coredns Corefile to add a consul { } block so lookups for .consul work.

consul {
    errors
    cache 30
    forward . 157.90.123.123:8600
}

However I need to replace that IP address with the "address of the node the coredns pod is running on".

Any ideas? Or other ways to solve this problem? Tx.

Upvotes: 1

Views: 1101

Answers (1)

David Tinker
David Tinker

Reputation: 9644

Comment from @mdaniel worked. Tx.

Edit coredns deployment. Add this to the container after volumeMounts:

env:
- name: K8S_NODE_IP
  valueFrom:
    fieldRef:
      fieldPath: status.hostIP

Edit coredns config map. Add to bottom of the Corefile:

consul {
    errors
    cache 30
    forward . {$K8S_NODE_IP}:8600
}

Check that DNS is working

kubectl run tmp-shell --rm -i --tty --image nicolaka/netshoot -- /bin/bash
nslookup myservice.service.consul
nslookup www.google.com
exit

Upvotes: 1

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