You should build an executable for your program (
go build) and then either write a script for upstart and it will run your program as a daemon for you, or use an external tool like daemonize. I prefer the latter solution, because it does not depend on a system-dependent upstart. With daemonize you can start your application like
daemonize -p /var/run/myapp.pid -l /var/lock/subsys/myapp -u nobody /path/to/myapp.exe
This will give you a well-behaving unix daemon process with all necessary daemon preparations done by daemonize.