I wanted an easy way to manage the contacts that get sent to the domain shared contacts so I thought why not just store them in a user account with a specific label and then push to the dsc when needed. I was able to pull the gal and send to a user with the following command
gam print gal formatjson quotechar "'" | gam csv - quotechar "'" gam user steve create contacts json ~JSON contactgroup "System Group: My Contacts"
So
I figured something like the following would work if I tried to take contacts labeled DomainContacts in my account and send them to the domain shared contacts. And Voila!
gam user steve print contacts contactgroup DomainContacts formatjson quotechar "'" | gam csv - quotechar "'" gam create contact json ~JSON
My next challenge though is how to I manage updates to the contacts when I change them in my account and how do I just add new contacts. I could simply kill all the domain shared contacts and create new ones but I was hoping for something more elegant than that.