Node Map from server to an external client returns INTERNAL DNS names

Couchbase Server Kubernetes
1

HI:

I am attempting to connect to a couchbase server from a client OUTSIDE the cluster. I have successfully deploy external-dns so that my kubernetes couchbase service correctly returns the IP addresses of the pods. (I’m using VPC-CNI so these IP’s are reachable directly from outside the cluster).

The PROBLEM is that I cannot retrieve data because when the client first connects (using the correct IP it got from external-dns) to the cluster, the cluster returns the NODE MAP of the DATA pods, but they’re NOT IP addresses. Instead they’re DNS names in the form clustername-0000.srv.cluster.local. The client doesn’t know what IP addresses go with that name, so the connection fails.

How can I get the returned Node Map from the server to be IP address and NOT DNS names like clustername-0000.svc.cluster.local

Here’s what’s happening:
client (10.1.0.10) looks up clustername.myexternaldomain.com from my external DNS

DNS server for clustername.myexternaldomain.com returns 3 reachable pod addresses:
10.1.0.1, 10.1.0.2, 10.1.0.3

client connects to 10.1.0.1 - gets node (of pods) map.

Node map includes clustername-0000.srv.cluster.local, clustername-0001.srv.cluster.local, clustername-0002.srv.cluster.local (these names are NOT resolvable by the client)

Connection fails.

2

Hey David,

Does your connection string indicate that you need to use external addresses, and does each Couchbase pod have the external DNS alternate address applied to the pod?

Thanks,

Justin Ashworth

3

HI Justin:
I’m not quite sure what the answer for the first part of your question is. Because of vpc-cni - each pod is directly reachable from outside the cluster. As for the 2nd part, I’m guessing not - I’m not sure how to do that (or even that this was possible).

Regards,
Dave

4

also - i just realized I mis-typed: when I said “nodes” I meant “pods” - my couchbase pods all have IP addresses from a subnet that’s reachable outside the cluster.

5

Hey David,

The Operator will add the alt addresses as necessary when configured correctly. I would recommend reading through this tutorial

Thanks,

-Justin