kubectl exec .. nslookup fails with command terminated with exit code 1

[subindani]

A user of the script reported this issue:

I tried to collect the API Manager logs but I got the error: command terminated with exit code 1.

./generate_postmortem.sh 0 --diagnostic-manager
Generating postmortem, please wait...
.......
command terminated with exit code 1
Created [/tmp/apiconnect-logs->CEST.tgz].

The command which fails with the error "command terminated with exit code 1" are all the ones which gets the nslookup output from inside the pod. This is viewable in the debug log. For example:

++ kubectl exec -n apic -c admin abc-apic-portal-www-0 -- nslookup <list of IP addresses>
command terminated with exit code 1

This is for 2018.4.1.9-ifix1.0 on a Kubernetes Cluster (Amazon EKS).