We are having an I/o timeout issue when pushing to docker hub.
FATA Put https://index.docker.io/v1/repositories/thecompany/therepo/: dial tcp: lookup index.docker.io on 192.168.0.1:53: read udp 192.168.0.1:53: i/o timeout
It seems to be irradic and iinitially erred out mid-push of one of the images. Subsequent push attempts error out immediately. Over the weekend I was able to get one of them to upload after many attempts (lucky timing somehow?)
Restarting boot2docker (as suggested in Pulling Docker images: i/o timeout) and even rebooting the machine seem to make no difference.