Use service port by default for LB type nodeport

[diptadas]

Default

apiVersion: voyager.appscode.com/v1beta1
kind: Ingress
metadata:
  name: test-ingress
  namespace: default
  annotations:
    ingress.appscode.com/type: NodePort
spec:
  rules:
  - host: voyager.appscode.test
    http:
      port: '8989'
      nodePort: '32666'
      paths:
      - path: /foo
        backend:
          serviceName: test-server
          servicePort: '80'

Generated haproxy.cfg:

# HAProxy configuration generated by https://github.com/appscode/voyager
# DO NOT EDIT!
global
	daemon
	stats socket /tmp/haproxy
	server-state-file global
	server-state-base /var/state/haproxy/
	# log using a syslog socket
	log /dev/log local0 info
	log /dev/log local0 notice
	tune.ssl.default-dh-param 2048
	ssl-default-bind-ciphers ECDHE-RSA-AES128-GCM-SHA256:ECDHE-ECDSA-AES128-GCM-SHA256:ECDHE-RSA-AES256-GCM-SHA384:ECDHE-ECDSA-AES256-GCM-SHA384:DHE-RSA-AES128-GCM-SHA256:DHE-DSS-AES128-GCM-SHA256:kEDH+AESGCM:ECDHE-RSA-AES128-SHA256:ECDHE-ECDSA-AES128-SHA256:ECDHE-RSA-AES128-SHA:ECDHE-ECDSA-AES128-SHA:ECDHE-RSA-AES256-SHA384:ECDHE-ECDSA-AES256-SHA384:ECDHE-RSA-AES256-SHA:ECDHE-ECDSA-AES256-SHA:DHE-RSA-AES128-SHA256:DHE-RSA-AES128-SHA:DHE-DSS-AES128-SHA256:DHE-RSA-AES256-SHA256:DHE-DSS-AES256-SHA:DHE-RSA-AES256-SHA:!aNULL:!eNULL:!EXPORT:!DES:!RC4:!3DES:!MD5:!PSK
defaults
	log global
	# https://cbonte.github.io/haproxy-dconv/1.7/configuration.html#4.2-option%20abortonclose
	# https://github.com/appscode/voyager/pull/403
	option dontlognull
	option http-server-close
	# Timeout values
	timeout client 50s
	timeout client-fin 50s
	timeout connect 50s
	timeout server 50s
	timeout tunnel 50s
	# Configure error files
	# default traffic mode is http
	# mode is overwritten in case of tcp services
	mode http
frontend http-0_0_0_0-8989
	bind *:8989 
	mode http
	option httplog
	option forwardfor
	acl is_proxy_https hdr(X-Forwarded-Proto) https
	acl acl_voyager.appscode.test hdr(host) -i voyager.appscode.test:8989
	acl acl_voyager.appscode.test:foo path_beg /foo
	use_backend test-server.default:80 if acl_voyager.appscode.test acl_voyager.appscode.test:foo
backend test-server.default:80
	server pod-test-server-68ddc845cd-x7dtv 172.17.0.4:8080

With use-node-port annotation

apiVersion: voyager.appscode.com/v1beta1
kind: Ingress
metadata:
  name: test-ingress
  namespace: default
  annotations:
    ingress.appscode.com/type: NodePort
    ingress.appscode.com/use-node-port: "true"
spec:
  rules:
  - host: voyager.appscode.test
    http:
      port: '8989'
      nodePort: '32666'
      paths:
      - path: /foo
        backend:
          serviceName: test-server
          servicePort: '80'

Generated haproxy.cfg:

# HAProxy configuration generated by https://github.com/appscode/voyager
# DO NOT EDIT!
global
	daemon
	stats socket /tmp/haproxy
	server-state-file global
	server-state-base /var/state/haproxy/
	# log using a syslog socket
	log /dev/log local0 info
	log /dev/log local0 notice
	tune.ssl.default-dh-param 2048
	ssl-default-bind-ciphers ECDHE-RSA-AES128-GCM-SHA256:ECDHE-ECDSA-AES128-GCM-SHA256:ECDHE-RSA-AES256-GCM-SHA384:ECDHE-ECDSA-AES256-GCM-SHA384:DHE-RSA-AES128-GCM-SHA256:DHE-DSS-AES128-GCM-SHA256:kEDH+AESGCM:ECDHE-RSA-AES128-SHA256:ECDHE-ECDSA-AES128-SHA256:ECDHE-RSA-AES128-SHA:ECDHE-ECDSA-AES128-SHA:ECDHE-RSA-AES256-SHA384:ECDHE-ECDSA-AES256-SHA384:ECDHE-RSA-AES256-SHA:ECDHE-ECDSA-AES256-SHA:DHE-RSA-AES128-SHA256:DHE-RSA-AES128-SHA:DHE-DSS-AES128-SHA256:DHE-RSA-AES256-SHA256:DHE-DSS-AES256-SHA:DHE-RSA-AES256-SHA:!aNULL:!eNULL:!EXPORT:!DES:!RC4:!3DES:!MD5:!PSK
defaults
	log global
	# https://cbonte.github.io/haproxy-dconv/1.7/configuration.html#4.2-option%20abortonclose
	# https://github.com/appscode/voyager/pull/403
	option dontlognull
	option http-server-close
	# Timeout values
	timeout client 50s
	timeout client-fin 50s
	timeout connect 50s
	timeout server 50s
	timeout tunnel 50s
	# Configure error files
	# default traffic mode is http
	# mode is overwritten in case of tcp services
	mode http
frontend http-0_0_0_0-8989
	bind *:8989 
	mode http
	option httplog
	option forwardfor
	acl is_proxy_https hdr(X-Forwarded-Proto) https
	acl acl_voyager.appscode.test hdr(host) -i voyager.appscode.test:32666
	acl acl_voyager.appscode.test:foo path_beg /foo
	use_backend test-server.default:80 if acl_voyager.appscode.test acl_voyager.appscode.test:foo
backend test-server.default:80
	server pod-test-server-68ddc845cd-x7dtv 172.17.0.4:8080

[tamalsaha]

} else if !useNodePort && port > 0 {