It's certainly worth looking at the standard flag package (http://golang.org/pkg/flag/) if you just need flag parsing.
I've also heard good things about https://github.com/spf13/cobra and https://github.com/codegangsta/cli.
Re:GitHub's “hub” tool rewritten in Golang
by stormbrew on Saturday January 03, 2015 @01:27AM
(#8830082)
Interestingly, the tool that turned me on to using go as a commandline tool builder was a little thing called jq [1] that's a huge huge help in dealing with json from bash scripts. I have no specific pointers, though, so I'm glad some other people jumped in.
Re:GitHub's “hub” tool rewritten in Golang
by xkarga00 on Friday January 02, 2015 @09:54PM
(#8829744)
Read this as well: http://blog.golang.org/json-and-go
From what you're writing it seems that it might be worth checking Go out for that. Would you happen to have pointers for using Go for that purpose?