Use container host's IP:port if we're connected to a swarm master

nginx.tmpl

@@ -44,24 +44,40 @@ upstream {{ $host }} {
 	{{ $addrLen := len $container.Addresses }}
 	{{/* If only 1 port exposed, use that */}}
 	{{ if eq $addrLen 1 }}
-		{{ with $address := index $container.Addresses 0 }}
-		   # {{$container.Name}}
-		   server {{ $address.IP }}:{{ $address.Port }};
+		{{ $address := index $container.Addresses 0 }}
+		{{/* If we got the containers from swarm and this container's port is published to host, use host IP:PORT */}}
+		{{ if and $container.Node $address.HostPort }}
+			# {{ $container.Node.Name }}/{{$container.Name}}
+			server {{ $container.Node.Address.IP }}:{{ $address.HostPort }};
+		{{/* If there is no swarm node or the port is not published on host, use container's IP:PORT */}}
+		{{ else }}
+			# {{$container.Name}}
+			server {{ $address.IP }}:{{ $address.Port }};
 		{{ end }}
 	{{/* If more than one port exposed, use the one matching VIRTUAL_PORT env var */}}
 	{{ else if $container.Env.VIRTUAL_PORT }}
 		{{ range $address := .Addresses }}
 		   {{ if eq $address.Port $container.Env.VIRTUAL_PORT }}
-		   # {{$container.Name}}
-		   server {{ $address.IP }}:{{ $address.Port }};
+			{{ if and $container.Node $address.HostPort }}
+				# {{ $container.Node.Name }}/{{$container.Name}}
+				server {{ $container.Node.Address.IP }}:{{ $address.HostPort }};
+			{{ else }}
+				# {{$container.Name}}
+				server {{ $address.IP }}:{{ $address.Port }};
+			{{ end }}
 		   {{ end }}
 		{{ end }}
 	{{/* Else default to standard web port 80 */}}
 	{{ else }}
 		{{ $address := where $container.Addresses "Port" "80" | first }}
 		{{ if $address }}
-			# {{$container.Name}}
-			server {{ $address.IP }}:80;
+			{{ if and $container.Node $address.HostPort }}
+				# {{ $container.Node.Name }}/{{$container.Name}}
+				server {{ $container.Node.Address.IP }}:{{ $address.HostPort }};
+			{{ else }}
+				# {{$container.Name}}
+				server {{ $address.IP }}:80;
+			{{ end }}
 		{{ else }}
 			# {{$container.Name}}
 			server {{ $container.IP }} down;