Cannot connect to the Docker daemon at unix:/var/r

问题:

I have applied every solution available on internet but still I cannot run Docker.

I want to use Scrapy Splash on my server.

Here is history of commands I ran.

docker run -p 8050:8050 scrapinghub/splash
sudo docker run -p 8050:8050 scrapinghub/splash
sudo usermod -aG docker $(whoami)
sudo docker run -p 8050:8050 scrapinghub/splash
newgrp docker
sudo docker run -p 8050:8050 scrapinghub/splash
reboot
sudo docker run -p 8050:8050 scrapinghub/splash
docker run -p 8050:8050 scrapinghub/splash

You can see I tried to restart my server as well, but it didnt help.

see output of ps -aux | grep docker

root@mani:/var/www/html# ps aux | grep docker
root      8524  0.0  0.8 127904 13964 ?        Ssl  17:21   0:00 /usr/bin/dockerd --raw-logs
root      8534  0.0  0.3  90588  5012 ?        Ssl  17:21   0:00 docker-containerd -l unix:///var/run/docker/libcontainerd/docker-containerd.sock --metrics-interval=0 --start-timeout 2m --state-dir /var/run/docker/libcontainerd/containerd --shim docker-containerd-shim --runtime docker-runc
root      8543  0.0  0.0   8812   764 pts/1    S+   17:21   0:00 grep --color=auto docker
root     16356  0.0  0.0  17200   964 pts/1    S    17:14   0:00 newgrp docker
root     20080  0.0  0.0  17200   964 pts/1    S    17:06   0:00 newgrp docker
root     30221  0.0  0.0  17200   964 pts/1    S    17:09   0:00 newgrp docker

回答1:

You can try out this :

systemctl start docker

It worked fine for me.

Ps: after if there is commands that you can't do without sudo, try this :

gpasswd -a $USER docker

回答2:

You can get this error if docker doesn't shut down cleanly. The following answer is for the docker snap package.

Run snap logs docker and look for the following:

Error starting daemon: pid file found, ensure docker is not running or delete /var/snap/docker/179/run/docker.pid

Deleting that file and restarting docker worked for me.

rm /var/snap/docker/179/run/docker.pid
snap stop docker
snap start docker

Make sure to replace '179' with the appropriate version number

回答3:

Just Run

sudo dockerd

dockerd is the daemon service for docker containers, because it is not running in background we're not able to take any actions related to the service, which needs be restarted.

回答4:

First, try with sudo, as the current user may not have access permissions to communicate to docker daemon i.e. /var/run/docker.sock

If its still not working, then, after the installation, simply stop the docker daemon as,

$ sudo service docker stop

And, run the following command to start the daemon in background,

$ sudo nohup docker daemon -H tcp://0.0.0.0:2375 -H unix:///var/run/docker.sock

To make working with Docker easier, you should add your username to the Docker users group. Adding a user to the group can be done with the command below

$ sudo usermod -aG docker $USER

Also, this step is mention at official documentation of docker Post-installation steps for Linux (https://docs.docker.com/engine/installation/linux/linux-postinstall/)

The Ubuntu 16.04 users can follow these steps,

Inside file /lib/systemd/system/docker.service change: ExecStart=/usr/bin/dockerd fd:// with ExecStart=/usr/bin/dockerd -H tcp://0.0.0.0:2375

Inside file /etc/init.d/docker change:

DOCKER_OPTS= with DOCKER_OPTS="-H ****tcp://0.0.0.0:2375 "

and then restart your machine. And, start playing with docker.

回答5:

This usually happened if you haven't stopped docker probably.

To resolve

service docker stop
cd /var/run/docker/libcontainerd
rm -rf containerd/*
rm -f docker-containerd.pid
service docker start

then "docker run...." to download your image and start the container as usual

回答6:

I'm running on root and tried below, it worked:

service docker start

export DOCKER_HOST="tcp://0.0.0.0:2375"

回答7:

here's the solution which works for me on Linux

systemctl start docker.

回答8:

I had this problem after closing docker will pulling a container docker pull mongo. At first I was getting weird errors so I purged docker sudo apt-get purge docker.io and reinstalled sudo apt-get install docker.io... all of this did nothing. I couldn't even run the hello-world container. The correct fix for me at least was:

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

After this I could pull mongo and run hello world.

Cheers!

回答9:

use this in ubuntu export DOCKER_HOST=tcp://localhost:2375

回答10:

export DOCKER_HOST=tcp://localhost:2375 is perfect for anyone who doesn't have sudo access and the user doesn't have access to unix:///var/run/docker.sock

回答11:

I was trying to run docker(just installed) in an instance of AWS when the message appears. I just write sudo service docker start and works fine for me.

Also see AWS with Docker

回答12:

I had the same problem for gitlab CI running node:lts image:

• I just restarted the docker daemon and restart the container, it worked for me.

回答13:

This worked for me, It might just work for you if you are using Ubuntu 16 or 18 (14 may also work). Easy to give a try:

Go to Ubuntu Software, type in Docker. Uninstall docker (108 mb) if it is preinstalled there. Install docker Now run the commands and see if the same error comes

The error:

After doing the above steps.

As you can see, it worked:)

回答14:

I faced same issue on Linux when I installed docker using yum (yum install docker).

Resolution: download docker binary from official site: docker install, unpack and follow the installation steps.

回答15:

For me the solution was to simply make sure I had installed the correct Docker package. For example, for Ubuntu the depreciated packages are:

• docker
• docker-engine
• docker.io
• containerd
• runc

For installation check https://docs.docker.com. Instructions are provided for Ubuntu, CentOS, Debian and Fedora at the time of writing.

回答16:

Make sure information in this path /etc/docker/daemon.json

{
  "registry-mirror": [
    "https://registry.docker-cn.com"
  ],
  "insecure-registries": [
    "192.168.199.100:5000"
  ]
}

delete

"insecure-registries": [
    "192.168.199.100:5000"
]

and runs well enter image description here

回答17:

This issue can be resolved permanently by running 1. systemctl enable docker 2. service docker start

回答18:

I just simply forget running the Docker Desktop in my mac, after running Docker Desktop, you will be good to go.

回答19:

It could be related to no disk space left on the hard drive. Make sure you have space left on the device, Docker can't start up if there isn't any space left.

回答20:

This exception comes when the service of docker is not running or the logged in user dont have the permission to access docker and generally it comes in RedHat

Using below command should resolve the issue

sudo service docker start