This is a question in two parts:
GCE instances don't currently have a public DNS name for their external IP address. But there is now a gcloud compute config-ssh
(docs) command that's a pretty good substitute.
This will insert Host
blocks into your ~/.ssh/config
file that contain the IP address and configuration for the host key.
Although this only helps with SSH (and SSH-based applications like Mosh and git+ssh), it does have a few advantages over DNS:
There is no caching/propagation delay as you might have with DNS
It pre-populates the right host key, and the host key is checked the right way even if the ephemeral IP address changes.
Example:
$ gcloud compute config-ssh
...
$ ssh myhost.us-west1-b.surly-koala-232