How to fix “dial unix /var/run/docker.sock: connect: permission denied” when group permissions seem correct?

Question

I\'m suddenly having issues after an update of Ubuntu 18.04: previously I\'ve used docker without issue on the system, but suddenly I cannot. As far as I can tell, the permissio

Answer 1

Ubuntu 18:04

sudo setfacl --modify user:$USER:rw /var/run/docker.sock

Answer 2

sudo setfacl --modify user:<user name or ID>:rw /var/run/docker.sock

It doesn't require a restart and is more secure than usermod or chown.

as @mirekphd pointed out, the user ID is required when the user name only exists inside the container, but not on the host.

Answer 3

Somehow, i found this page when i have't correct permissons on my docker.sock after my Docker installation. So, if you have the same issue, you can read this:

$ sudo adduser $USER docker does not work because the group is "root" not "docker"

$ ls -l /var/run/docker.sock srw-rw---- 1 root root 0 Jul 11 09:48 /var/run/docker.sock so it should be $ sudo adduser $USER root

from a non-snap installed machine, the group is "docker"

# ls -l /var/run/docker.sock srw-rw---- 1 root docker 0 Jul 3 04:18 /var/run/docker.sock The correct way is, according to docker.help you have to run the followings BEFORE sudo snap install docker

$ sudo addgroup --system docker $ sudo adduser $USER docker $ newgrp docker then the group will be "docker"

$ ls -l /var/run/docker.sock srw-rw---- 1 root docker 0 Jul 11 10:59 /var/run/docker.sock

Source: https://github.com/docker-archive/docker-snap/issues/1 (yes, first issue :D)

The easyest way to fix it is to run:

$ sudo setfacl -m "g:docker:rw" /var/run/docker.sock

And then, as it already metioned, run following commands for your user:

$sudo addgroup --system docker
$sudo adduser $USER docker
$newgrp docker

That's it :) Have fun!

Answer 4

Specific to Ubuntu, there is a known issue with lightdm that removes secondary groups from the user as part of the GUI login. You can follow that issue here: https://bugs.launchpad.net/lightdm/+bug/1781418

You can try switching off of lightdm or apply the workaround mentioned in the bug report:

[Comment out the below lines from /etc/pam.d/lightdm:]

auth optional pam_kwallet.so
auth optional pam_kwallet5.so

Temporary options include logging into your machine with something like an ssh or su -l command, or running the newgrp docker command. These will only affect the current shell and would need to be done again with each new terminal.

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Outside of this issue, the general commands to give a user direct access to the docker socket (and therefore root access to the host) are:

sudo usermod -aG docker $(id -un) # you can often use $USER in place of the id command
newgrp docker # affects the current shell, logging out should affect all shells

Answer 5

I did the quick fix and it worked immediately.

sudo chmod 777 /var/run/docker.sock

Answer 6

add the user to the docker group.

sudo usermod -aG docker $USER
sudo reboot