当我把Docker版本更新到0.8.0后，我在输入sudo Docker version时得到了一个错误消息:
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，我得到了这个:
[/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
我怎么解决这个问题?
找出Docker不能工作的原因的最好方法是手动运行守护进程。
$ sudo service docker stop
$ ps aux | grep docker # do this until you don't see /usr/bin/docker -d
$ /usr/bin/docker -d
Docker守护进程记录到STDOUT，因此它将开始输出它正在做的任何事情。
这就是我的问题所在:
[8bf47e42.initserver()] Creating pidfile
2015/01/11 15:20:33 pid file found, ensure docker is not running or delete /var/run/docker.pid
这是因为实例是从另一个虚拟机克隆的。我只需要删除pidfile，之后一切都正常了。
当然，我并不是盲目地假设这样可以工作，而是建议再次手动运行守护进程，并在启动服务备份之前检查日志输出是否有其他错误。
检查你是否正在使用Docker Machine:)
运行docker-machine env default就可以了。
因为根据文档:
Docker Machine is a tool that lets you install Docker Engine on
virtual hosts, and manage the hosts with docker-machine commands. You
can use Machine to create Docker hosts on your local Mac or Windows
box, on your company network, in your data center, or on cloud
providers like AWS or Digital Ocean.
Using docker-machine commands, you can start, inspect, stop, and
restart a managed host, upgrade the Docker client and daemon, and
configure a Docker client to talk to your host.
Point the Machine CLI at a running, managed host, and you can run
docker commands directly on that host. For example, run
docker-machine env default to point to a host called default, follow on-screen
instructions to complete env setup, and run docker ps,
docker run hello-world, and so forth.
https://docs.docker.com/machine/overview/
Linux
Linux安装后步骤文档揭示了以下步骤:
创建docker组。
Sudo groupadd docker
将用户添加到docker组。
sudo usermod -aG docker $(whoami)
退出并重新登录以确保docker以正确的权限运行。
码头工人开始。
Sudo服务docker启动
Mac OS X
正如Dayel Ostraco所说，有必要添加环境变量:
docker-machine start # Start virtual machine for docker
docker-machine env # It's helps to get environment variables
eval "$(docker-machine env default)" # Set environment variables
docker-machine start命令输出注释来指导这个过程。
