fix: port-forward socat getaddrinfo: Name or service not known

[andrewrynhard]

Terminal 1

kubectl port-forward etcd-master-0 2379:2379 -n kube-system
Forwarding from 127.0.0.1:2379 -> 2379

Terminal 2

curl localhost:2379/v2
curl: (52) Empty reply from server

Terminal 1

kubectl port-forward etcd-master-0 2379:2379 -n kube-system
Forwarding from 127.0.0.1:2379 -> 2379
Handling connection for 2379
E0402 21:26:31.026140   78292 portforward.go:331] an error occurred forwarding 2379 -> 2379: error forwarding port 2379 to pod 67354788607ba8b9caad4f69c7a4256581b46655281b6fd182ec0fd21ef0591c, uid : exit status 1: 2018/04/03 04:26:29 socat[11867] E getaddrinfo("localhost", "NULL", {1,2,1,6}, {}): Name or service not known