dual stack services and MetalLB 0.12.0

[DerRockWolf]

Since the release of MetalLB v0.12.0 they support dual stack services. It isn't necessary to create two separate services
This means that my changes from #187 can be extended so that it is also possible to create dual stack services with type LoadBalancer.

If you want me to extend the chart to support the dual stack LB services, should it be backwards compatible?
If yes I would create a new value (like dualStack.separateLBs that is set to true by the values.yaml

Someday we should also remove the loadBalancerIP field because it will be deprecated in the future and it also can't be used for dual stack services.

[MoJo2600]

Yes, removal of the loadBalancerIP field is a good idea. I think it is a good idea to extend #187 with this feature.

I'm a little hesitant if we should drop backward compatibility... But the dual stack setup would make the setup a bit easier. Do you know if there is a scenario where dual stack LBs would still be needed?

[DerRockWolf]

The only scenario I came up with would be if the user uses (or needs to use) a LB that doesn't support dual stack services and so needs separate ones.
But those users could manually deploy separate services to achieve a setup like with the current chart. I've used to do this with ingress-nginx before the dual stack support of MetalLB.

I think that if we also remove the loadBalancerIP fields (this would also be a breaking change), we could just make a new major version and include both breaking changes.

[DerRockWolf]

I've started with the implementation.

I went with both breaking changes. If you would like to have the DS changes backwards compatible just tell me :)