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

Ubuntu的: 我更新docker的时候就发生了。您需要取消服务和套接字的掩码，然后重新启动服务。以下是对我有用的:

systemctl unmask docker.service
systemctl unmask docker.socket
systemctl start docker.service

幕后发生了什么 Systemd还能够通过将一个单元链接到/dev/null，自动或手动地将其标记为完全不可启动这称为屏蔽单元，可以使用mask命令实现。

sudo systemctl mask docker.service

你可以使用以下方法查看屏蔽服务的列表:

sudo systemctl list-unit-files

要启用自动/手动启动服务，您需要使用:

sudo sytemctl unmask docker.service

现在该服务将被启用，如下所示

2016-08-25 02:22:01

其他回答

也许这将帮助某些人，因为错误消息非常没有帮助，而且我已经多次执行所有标准许可步骤，但都无济于事。

Docker偶尔会在阻碍访问的地方留下幽灵环境变量，尽管您的系统在其他方面是正确设置的。下面的shell命令可以使它再次可访问，如果你已经让它运行了一点，它只是在重新启动后停止合作:

unset DOCKER_HOST
unset DOCKER_TLS_VERIFY
unset DOCKER_TLS_PATH
docker ps

I had a previously working docker install, and after rebooting my laptop it simply refused to work. Was correctly added to the docker user group, had the correct permissions on the socket, etc, but could still not run docker login, docker run ..., etc. This fixed it for me. Unfortunately I have to run this on each reboot. This is mentioned on a couple of github issues also as a workaround, although it seems like a bug that this is a persistent barrier to correct operation of Docker (note: I am on Arch Linux, not OSX, but this was the same issue for me).

2018-07-18 21:07:49

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

我也有同样的问题。为了解决这个问题我已经挣扎了两天了。

只有当我这样做的时候，它才起作用:

根据Docker的教程，你需要添加Docker密钥，如果还没有添加，使用: $ sudo wget - qo - https://get.docker.com/gpg | sudo apt-key add - 然后确保你为自己授予docker特权，使用: $ sudo usermod -aG docker $USER

希望这也能帮助到你。

2015-11-10 17:31:01

给予非根访问-从docker

如果docker组不存在，请添加。

$ sudo groupadd docker

将连接用户“${user}”添加到docker组中。

更改用户名以匹配您的首选用户。

您可能需要注销并重新登录这才生效。

$ sudo gpasswd -a ${USER} docker

重新启动Docker守护进程。

$ sudo service docker restart

2016-12-21 19:11:31