[piqiu@benjaminpro ~]$boot2docker start
Waiting for VM and Docker daemon to start...
..........................................................................oooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooo
Started.
  Trying to get Docker socket one more time
Error requesting socket: exit status 255
Auto detection of the VM‘s Docker socket failed.
Please run `boot2docker -v up` to diagnose.

[piqiu@benjaminpro ~]$boot2docker ip

Failed to get VM Host only IP address.
	Was the VM initialized using boot2docker?

i google the issue:https://github.com/boot2docker/boot2docker/issues/392

我发现是我在操作VirtualBox的时候把Port forwarding里的本机映射删除了。

解决方法：

[piqiu@benjaminpro ~]$boot2docker delete
[piqiu@benjaminpro ~]$boot2docker init
Initialization of virtual machine "boot2docker-vm" complete.
Use `boot2docker up` to start it.
[piqiu@benjaminpro ~]$boot2docker up
Waiting for VM and Docker daemon to start...
........................ooooooooooooooooooooooo
Started.
Writing /Users/piqiu1/.boot2docker/certs/boot2docker-vm/ca.pem
Writing /Users/piqiu1/.boot2docker/certs/boot2docker-vm/cert.pem
Writing /Users/piqiu1/.boot2docker/certs/boot2docker-vm/key.pem
Your environment variables are already set correctly.

[piqiu@benjaminpro ~]$boot2docker ip
192.168.59.103
[piqiu@benjaminpro ~]$boot2docker ssh
                        ##         .
                  ## ## ##        ==
               ## ## ## ## ##    ===
           /"""""""""""""""""\___/ ===
      ~~~ {~~ ~~~~ ~~~ ~~~~ ~~~ ~ /  ===- ~~~
           \______ o           __/
             \    \         __/
              \____\_______/
 _                 _   ____     _            _
| |__   ___   ___ | |_|___ \ __| | ___   ___| | _____ _ __
| ‘_ \ / _ \ / _ \| __| __) / _` |/ _ \ / __| |/ / _ \ ‘__|
| |_) | (_) | (_) | |_ / __/ (_| | (_) | (__|   <  __/ |
|_.__/ \___/ \___/ \__|_____\__,_|\___/ \___|_|\_\___|_|
Boot2Docker version 1.7.1, build master : c202798 - Wed Jul 15 00:16:02 UTC 2015
Docker version 1.7.1, build 786b29d