Add falg to report node internal IP address in ingress status

[aledbf]

fixes #1414
fixes #1407

[k8s-reviewable]

This change is 

[coveralls]

Coverage decreased (-0.06%) to 33.518% when pulling 284448f on aledbf:internal-ip into 4479b54 on kubernetes:master.

[gyliu513]

This is a breaking change and it bring some problem to current cluster as I cannot get the internalIPAddress of my ingress, such as issue #2047

The original logic is getting both externalIP and internalIP, but is treating externalIP as priority, if no externalIP, it will use internalIP https://github.com/kubernetes/ingress-nginx/blob/nginx-0.9.0-beta.12/core/pkg/k8s/main.go#L81-L102 , but current logic using a flag to enable end user can either use internalIP or externalIP https://github.com/kubernetes/ingress-nginx/blob/nginx-0.9.0/internal/k8s/main.go#L39-L65 , I think we should keep original logic to use externalIP first and then internalIP, comments @aledbf

[kunalpuriii]

@gyliu513 @aledbf I have small cluster in LAB where i am testing this arguments, I have enabled - --report-node-internal-ip-address=true but in the ingress I still see the External-IP, is this correct behavior of the argument.

Documentation states : --report-node-internal-ip-address bool Falg to report node internal IP address in ingress status (default false). If your node only has internal ip, this should set to true, or thre controller will report empty ips to ingress.

[root@aalmglnams00001 ~] kubectl get svc -n nginx-ingress
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE
nginx-ingresss LoadBalancer 192.168.209.85 172.23.84.101 443:30110/TCP 9m48s
[root@aalmglnams00001 ~] kubectl get ing
NAME HOSTS ADDRESS PORTS AGE
cafe-ingress cafe.example.com 172.23.84.101 80, 443 65d
frontend notebook.example.com 172.23.84.101 80 65d

[root@aalmglnams00001 ~] kubectl get nodes -o wide
NAME STATUS ROLES AGE VERSION INTERNAL-IP EXTERNAL-IP OS-IMAGE KERNEL-VERSION CONTAINER-RUNTIME
aalmglnams00001 Ready master 69d v1.16.0 172.24.72.2 Red Hat Enterprise Linux Server 7.8 (Maipo) 3.10.0-1127.el7.x86_64 docker://18.6.3
aalmglnams00002 Ready 69d v1.16.0 172.24.72.3 Red Hat Enterprise Linux Server 7.8 (Maipo) 3.10.0-1127.el7.x86_64 docker://18.6.3
[root@aalmglnams00001 ~]

Please confirm.

Thanks
Kunal