NGINX TCP Ingresses do not bind on IPv6

[justjanne]

Steps to reproduce:

1. Create an nginx ingress controller
2. Use the TCP ConfigMap to add a TCP Ingress

Expected Behaviour:

Nginx binds this on IPv4 and IPv6

Actual Behaviour:

Nginx binds only on IPv4 for the configured port.

Background Information:

The origin of the issue is in the listen directive in the file controllers/nginx/rootfs/etc/nginx/template/nginx.tmpl. This is configured to only listen to IPv4.

In December 2016, several patches were merged to change the listen directives for the ports :80 and :443 to handle IPv6. Neither did address TCP Ingresses.

Potential Fix:

The same technique currently used for :80 and :443 could also be applied here, replacing

listen {{ $tcpServer.Port }};

with

listen {{ if $IsIPV6Enabled }}[::]:{{ end }}{{ $tcpServer.Port }} {{ if $IsIPV6Enabled }}ipv6only=off{{ end }};

This evaluates, if IPv6 is enabled, to

listen [::]:{{ $tcpServer.Port }} ipv6only=off;

and otherwise to

listen {{ $tcpServer.Port }};

Related issues:

The same happens with UDP Ingresses, and the same fix would be appropriate.

[aledbf]

@justjanne please check if the image quay.io/aledbf/nginx-ingress-controller:0.127 works for you