Docker无法连接到docker守护程序
在我将Docker版本更新为 0.8.0 后，输入 sudo docker版本时会收到错误消息：
After I update my Docker version to 0.8.0, I get an error message while entering sudo docker version:
Client version: 0.8.0
Go version (client): go1.2
Git commit (client): cc3a8c8
2014/02/19 12:54:16 Can't connect to docker daemon. Is 'docker -d' running on this host?
我按照说明输入命令 sudo docker -d ，我得到这个：
And I've followed the instructions and entered command sudo docker -d, and I got this:
[/var/lib/docker|2462000b] +job initserver()
[/var/lib/docker|2462000b.initserver()] Creating server
open /var/lib/docker/aufs/layers/cf2414da53f9bcfaa48bc3d58360d7f1cfd3784e4fe51fbef95197709dfc285d: no such file or directory[/var/lib/docker|2462000b] -job initserver() = ERR (1)
2014/02/19 12:55:57 initserver: open /var/lib/docker/aufs/layers/cf2414da53f9bcfaa48bc3d58360d7f1cfd3784e4fe51fbef95197709dfc285d: no such file or directory
如何解决问题？
在Linux 中：
从创建Docker组部分，有必要将用户添加到 docker group：
From Create a Docker group section, it is necessary to add the user to the docker group:
sudo usermod -aG docker $(whoami)
注意：
注销并重新登录，确保您的用户正确使用权限。
Note:
Log out and log back in. This ensures your user is running with the correct permissions.
在Mac OS X中
As Dayel Ostraco 表示添加环境变量是必要的：
As Dayel Ostraco says is necessary to add environments variables:
$ docker-machine start # Start virtual machine for docker
$ docker-machine env # It's helps to get environment variables
$ eval "$(docker-machine env default)" # Set environment variables
docker-machine start 命令输出注释以指导该过程。
The docker-machine start command outputs the comments to guide the process.