how to update docker in coreos

Question

I typed docker version into a newly provisioned coreos instant on ec2 and I got this message

Client version: 0.6.3
Go version (client): go1.1.2
Git commit (client): b0a49a3
Server version: 0.6.3
Git commit (server): b0a49a3
Go version (server): go1.1.2
Last stable version: 0.7.3, please update docker

how do I update docker?

Answer 1

To update CoreOS manually type in your shell:

update_engine_client -update

Answer 2

CoreOS and the tools it ships are updated automatically as new versions come out.

The CoreOS version on the EC2 marketplace is always a few versions behind, but if you wait a few minutes after booting a machine it should execute an auto-update and then be up to date.

If you want to manually run a new docker binary before it is updated in CoreOS, you can download the binary and run a local docker unit file: https://gist.github.com/philips/7555876