Implement lb-method fixes #94

[sajal]

Image built from my fork : turbobytes/nginx-ingress:0.9.0

This adds a configmap key lb-method and annotation nginx.org/lb-method as suggested by @pleshakov in #94 .

If this setting is not blank, then the value is pasted into the upstream block in the nginx config. This is configurable per Ingress, and not per service.

[pleshakov]

@sajal
thanks for the PR!

Here is a couple of suggestions:

1. In the documentation, could you change the default value from N/A to "" and also add the following statement after "Sets the load balancing method.": The "" specifies the round-robin method.
2. I think it is better to pass the ingCfg to the createUpstream and extract the method from it, rather than from ingEx as in https://github.com/turbobytes/kubernetes-ingress/blob/e4a43d4e700969fd9d71a90fd879350ba2c3f486/nginx-controller/nginx/configurator.go#L449 Thus, we don't need to have LBMethod string as part of IngressEx. It is sufficient to have LBMethod only in Config and Upstream

[sajal]

@pleshakov Good ideas. I will look into them now.

[sajal]

@pleshakov Now im passing LBMethod as argument instead of using IngressEx

[pleshakov]

@sajal great! thx

I have two more suggestions:

Could you move this logic https://github.com/turbobytes/kubernetes-ingress/blob/b819d7e0acdb119541b7d91228167af99c6e5b5f/nginx-controller/nginx/configurator.go#L86-L88 to the createConfig method for consistency. This way all annotation parsing happens only in one place.

Could you also squash you commits into a single one?

[sajal]

Ah so I will overwrite the annotation value id present at ingCfg in createConfig.

[sajal]

@pleshakov : moved annotation checking into createConfig and squash'd