Nginx ingress controller crashes if host does not have IPv6

[kongslund]

When attempting to use nginx-ingress-controller:0.9.0-beta.3 I experience that a pod crashes at startup time if the host does not have IPv6 (i.e. kernel is configured with ipv6.disable=1). If I enable IPv6 then everything works fine.

I would expect that it should work fine even if IPv6 is disabled.

Log output from nginx-ingress-controller pod when IPv6 is missing on the host

I0411 10:45:34.818631       5 launch.go:96] &{NGINX 0.9.0-beta.3 git-3dd7461 git@github.com:ixdy/kubernetes-ingress.git}
I0411 10:45:34.818701       5 launch.go:99] Watching for ingress class: nginx
I0411 10:45:34.819403       5 launch.go:245] Creating API server client for https://10.96.0.1:443
I0411 10:45:34.821757       5 nginx.go:127] starting NGINX process...
I0411 10:45:34.919300       5 launch.go:115] validated kube-system/default-http-backend as the default backend
I0411 10:45:34.940097       5 controller.go:1071] starting Ingress controller
I0411 10:45:34.966894       5 leaderelection.go:247] lock is held by nginx-ingress-controller-8hb8q and has not yet expired
W0411 10:45:35.958639       5 queue.go:87] requeuing kube-system/ingress-controller-leader, err deferring sync till endpoints controller has synced
I0411 10:45:45.528204       5 metrics.go:34] changing prometheus collector from  to default
W0411 10:45:45.636890       5 queue.go:87] requeuing default/kubernetes, err
-------------------------------------------------------------------------------
Error: exit status 1
nginx: the configuration file /tmp/nginx-cfg196544711 syntax is ok
2017/04/11 10:45:45 [emerg] 19#19: socket() [::]:80 failed (97: Address family not supported by protocol)
nginx: [emerg] socket() [::]:80 failed (97: Address family not supported by protocol)
nginx: configuration file /tmp/nginx-cfg196544711 test failed

-------------------------------------------------------------------------------
I0411 10:45:47.654922       5 main.go:50] Received SIGTERM, shutting down
I0411 10:45:47.654999       5 controller.go:1056] shutting down controller queues
I0411 10:45:47.656298       5 main.go:39] shutting down Ingress controller...
I0411 10:45:47.656332       5 main.go:41] Handled quit, awaiting pod deletion
I0411 10:45:47.656519       5 main.go:58] Exiting with 0

[aledbf]

@kongslund this is fixed in master #578