Allow exposing port range like Docker/Docker-compose

[mvh77]

Hi,

Docker & docker-compose allow exposing port ranges with syntax 9000-9500:9000-9500/udp. Kontena doesn't seem to support this as the parser fails for this syntax. I have a case where I need to expose potentially hundreds of RTP ports out of a PBX system towards an ITSP SIP trunk.

Thanks!

[SpComb]

You can consider using network_mode: host instead of published ports, if you're okay with exposing any and all ports that the service listens on, and only running one of those externally exposed service instances per node.