Docker命令无法连接到Docker守护进程

我想转移到Docker，所以我刚刚开始摆弄它。我已经在VirtualBox Ubuntu 15.10 (Wily Werewolf)安装上安装了Docker，然后按照这里的建议，我尝试运行一个基本的nginx Docker镜像:

$ docker run --name mynginx1 -P -d nginx
Cannot connect to the Docker daemon. Is the docker daemon running on this host?

所以我检查了Docker是否在运行:

$ sudo service docker status
● docker.service - Docker Application Container Engine
   Loaded: loaded (/lib/systemd/system/docker.service; enabled; vendor preset: enabled)
   Active: active (running) since vr 2015-11-06 08:41:48 CET; 15min ago
     Docs: https://docs.docker.com
 Main PID: 7542 (docker)
   CGroup: /system.slice/docker.service
           └─7542 /usr/bin/docker daemon -H fd://

nov 06 08:41:47 kramer65-VirtualBox systemd[1]: Starting Docker Application Container Engine...
nov 06 08:41:47 kramer65-VirtualBox docker[7542]: time="2015-11-06T08:41:47.900410966+01:00" level=info msg="API ...ock"
nov 06 08:41:48 kramer65-VirtualBox docker[7542]: time="2015-11-06T08:41:48.033514149+01:00" level=info msg="Fire...lse"
nov 06 08:41:48 kramer65-VirtualBox docker[7542]: time="2015-11-06T08:41:48.141594321+01:00" level=info msg="Defa...ess"
nov 06 08:41:48 kramer65-VirtualBox docker[7542]: time="2015-11-06T08:41:48.416294436+01:00" level=warning msg="Y...it."
nov 06 08:41:48 kramer65-VirtualBox docker[7542]: time="2015-11-06T08:41:48.565507576+01:00" level=info msg="Load...rt."
nov 06 08:41:48 kramer65-VirtualBox docker[7542]: time="2015-11-06T08:41:48.567907022+01:00" level=info msg="Load...ne."
nov 06 08:41:48 kramer65-VirtualBox docker[7542]: time="2015-11-06T08:41:48.567945214+01:00" level=info msg="Daem...ion"
nov 06 08:41:48 kramer65-VirtualBox docker[7542]: time="2015-11-06T08:41:48.567969891+01:00" level=info msg="Dock....9.0
nov 06 08:41:48 kramer65-VirtualBox systemd[1]: Started Docker Application Container Engine.
Hint: Some lines were ellipsized, use -l to show in full.

这表明Docker守护进程实际上已经在运行，但为了确保我只是手动启动了Docker守护进程:

$ sudo docker daemon
INFO[0000] API listen on /var/run/docker.sock           
INFO[0000] [graphdriver] using prior storage driver "aufs" 
INFO[0000] Firewalld running: false                     
INFO[0000] Default bridge (docker0) is assigned with an IP address XXX.XX.X.X/XX. Daemon option --bip can be used to set a preferred IP address 
WARN[0000] Your kernel does not support swap memory limit. 
INFO[0000] Loading containers: start.                   

INFO[0000] Loading containers: done.                    
INFO[0000] Daemon has completed initialization          
INFO[0000] Docker daemon                                 commit=76d6bc9 execdriver=native-0.2 graphdriver=aufs version=1.9.0

然后我尝试再次运行图像，但结果相同:

$ docker run --name mynginx1 -P -d nginx
Cannot connect to the Docker daemon. Is the docker daemon running on this host?

我试着执行命令，但没有效果。我哪里做错了?

当前回答

我在运行docker时也有同样的问题。

可以使用sudo用户执行命令:

sudo docker ***your command here***

2016-08-08 10:26:58

其他回答

将用户添加到docker组

如果docker组不存在，添加它: Sudo groupadd docker 将连接用户${user}加入docker组: sudo gpasswd -a ${USER} docker 重启Docker守护进程: Sudo服务docker重启要么执行newgrp docker，要么注销/登录以激活对组。

2016-01-19 06:08:09

注意:当我忘记用sudo运行docker命令时，我从问题的标题中得到错误:

Sudo docker run…

(Ubuntu 15.10)

2015-12-01 12:18:59

对于那些已经尝试重新启动您的机器的人，按照docker env文档中的说明取消设置环境变量DOCKER_HOST，其余的都只是尝试使用