Can not pull/push images after update docker to 1.12
I had the same issue.
This helped for me:
Create or modify /etc/docker/daemon.json on the client machine
{ "insecure-registries":["myregistry.example.com:5000"] }
Restart docker daemon
sudo /etc/init.d/docker restart
For Mac Users:Update the docker preferences using the (docker) icon in top bar
Preferences -> Daemon -> Insecure Registry [Click (+) sign] -> add :port
hit "Apply & Restart" button at bottom