Fix default server

[thetechnick]

If I create a default server using a ingress config like this:

apiVersion: extensions/v1beta1
kind: Ingress
metadata:
  name: default-backend
  namespace: default
spec:
  backend:
    serviceName: default-backend
    servicePort: 80

the configuration is created, but because of a missing default_server option in the servers listen directive it is not actually been used as the default backend.

[pleshakov]

@thetechnick
Thx!

In this case only one default_server can be created, which is enforced by NGINX. This also entails that all the Ingress rules with empty hostnames will be rejected: NGINX will fail to reload, you'll get something like:

nginx: [emerg] a duplicate default server for 0.0.0.0:80 in /etc/nginx/conf.d/default_server.conf:19
nginx: configuration file /etc/nginx/nginx.conf test failed

It also solves this #52

However, since NGINX configuration stays invalid until we remove all Ingress rules with the empty hostnames until there is only one, I think we should not merge it until we have a handling of cases when Ingress rules have the same hostname in the controller.

[thetechnick]

Closing because of time constraints