I installed Docker in my machine where I have Ubuntu OS. When I run:
sudo docker run hello-world
All is ok, but I want to hide the sudo
command to make the command shorter.
If I write the command without sudo
docker run hello-world
That displays the following:
docker: Got permission denied while trying to connect to the Docker daemon socket at unix:///var/run/docker.sock: Post http://%2Fvar%2Frun%2Fdocker.sock/v1.35/containers/create: dial unix /var/run/docker.sock: connect: permission denied. See 'docker run --help'.
The same happens when I try to run:
docker-compose up
How can I resolve this?
If you want to run docker as non-root user then you need to add it to the docker group.
Create the docker group if it does not exist
$ sudo groupadd docker
Add your user to the docker group.
$ sudo usermod -aG docker $USER
Run the following command or Logout and login again and run (that doesn't work you may need to reboot your machine first)
$ newgrp docker
Check if docker can be run without root
$ docker run hello-world
Reboot if still got error
$ reboot
Warning
The docker group grants privileges equivalent to the root user. For details on how this impacts security in your system, see Docker Daemon Attack Surface..
Taken from the docker official documentation: manage-docker-as-a-non-root-user
After an upgrade I got the permission denied. Doing the steps of 'mkb' post install steps don't have change anything because my user was already in the 'docker' group; I retry-it twice any way without success.
After an search hour this following solution finaly worked :
sudo chmod 666 /var/run/docker.sock
Solution came from Olshansk.
Look like the upgrade have recreate the socket without enough permission for the 'docker' group.
Problems
This hard chmod open security hole and after each reboot, this error start again and again and you have to re-execute the above command each time. I want a solution once and for all. For that you have two problems :
1) Problem with SystemD : The socket will be create only with owner 'root' and group 'root'. You can check this first problem with this command : ls -l /lib/systemd/system/docker.socket If every this is good, you should see 'root/docker' not 'root/root'.
2 ) Problem with graphical Login : https://superuser.com/questions/1348196/why-my-linux-account-only-belongs-to-one-group You can check this second problem with this command : groups If everything is correct you should see the docker group in the list. If not try the command sudo su $USER -c groups if you see then the docker group it is because of the bug.
Solutions
If you manage to to get a workaround for the graphical login, this should do the job :
sudo chgrp docker /lib/systemd/system/docker.socket
sudo chmod g+w /lib/systemd/system/docker.socket
But If you can't manage this bug, a not so bad solution could be this :
sudo chgrp $USER /lib/systemd/system/docker.socket
sudo chmod g+w /lib/systemd/system/docker.socket
This work because you are in a graphical environnement and probably the only user on your computer. In both case you need a reboot (or an sudo chmod 666 /var/run/docker.sock
)
:ro
on the end... as soon as I added that I was good to go
Add docker group
$ sudo groupadd docker
Add your current user to docker group
$ sudo usermod -aG docker $USER
Switch session to docker group
$ newgrp - docker
Run an example to test
$ docker run hello-world
newgrp
command prompted for a password and didn't accept my user password. Instead su - $USER
worked to avoid logging out/in.
Add current user to docker group
sudo usermod -aG docker $USER
Change the permissions of docker socket to be able to connect to the docker daemon /var/run/docker.sock
sudo chmod 666 /var/run/docker.sock
I solve this error with the command :
$ sudo chmod 666 /var/run/docker.sock
It only requires the changes in permission of sock file.
sudo chmod 666 /var/run/docker.sock
this will work definitely.
You can always try Manage Docker as a non-root user
paragraph in the https://docs.docker.com/install/linux/linux-postinstall/ docs.
After doing this also if the problem persists then you can run the following command to solve it:
sudo chmod 666 /var/run/docker.sock
chmod 666
) is a security disaster... This should never be recommended.
root
on the host system! See this for example: fosterelli.co/privilege-escalation-via-docker and many other resources on docker privilege escalation. Making the socket world writable effectively gives all UNIX users root
privileges.
666
permissions. 660
or 640
should be more than enough.
Fix Docker Issue: (Permission denied)
Create the docker group if it does not exist: sudo groupadd docker
See number of super users in the available system: grep -Po '^sudo.+:\K.*$' /etc/group
Export the user in linux command shell: export USER=demoUser
Add user to the docker group: sudo usermod -aG docker $USER
Run the following command/ Login or logout: newgrp docker
Check if docker runs ok or not: docker run hello-world
Reboot if you still get an error: reboot
If it does not work, run this command:
sudo chmod 660 /var/run/docker.sock
777
shouldn't be used
777
option and it worked😅
777
means that anyone can do anything with those files
777
! Use 660
or 640
660
doesn't work. For me it was set per default.
Got permission denied while trying to connect to the Docker daemon socket at unix:///var/run/docker.sock: Get http://%2Fvar%2Frun%2Fdocker.sock/v1.40/images/json: dial unix /var/run/docker.sock: connect: permission denied
sudo chmod 666 /var/run/docker.sock
This fix my problem.
We always forget about ACLs
. See setfacl
.
sudo setfacl -m user:$USER:rw /var/run/docker.sock
sudo apt install acl
To fix that issue, I searched where is my docker and docker-compose installed. In my case, docker
was installed in /usr/bin/docker
and docker-compose
was installed in /usr/local/bin/docker-compose
path. Then, I write this in my terminal:
To docker:
sudo chmod +x /usr/bin/docker
To docker-compose
:
sudo chmod +x /usr/local/bin/docker-compose
Now I don't need write in my commands docker the word sudo
/***********************************************************************/
ERRATA:
The best solution of this issue was commented by @mkasberg. I quote comment:
That might work, you might run into issues down the road. Also, it's a security vulnerability. You'd be better off just adding yourself to the docker group, as the docs say. sudo groupadd docker, sudo usermod -aG docker $USER.
Docs:
https://docs.docker.com/install/linux/linux-postinstall/
docker
group, as the docs say. sudo groupadd docker
, sudo usermod -aG docker $USER
.
Seriously guys. Do not add Docker in your groups or modifies the socket posix (without a hardening SELinux), it's a simple way to make a root privesc. Just add an alias in your .bashrc, it's simpler and safer as : alias dc='sudo docker'.
ubuntu 21.04 systemd socket ownership
Let me preface, this was a perfectly suitable solution for me during local development and I got here searching for ubuntu docker permission error
so i'll just leave this here.
I didn't own the unix socket, so I chowned it.
sudo chown $(whoami):$(whoami) /var/run/docker.sock
Another, more permanent solution for your dev environment, is to modify the user ownership of the unix socket creation. This will give your user the ownership, so it'll stick between restarts:
sudo nano /etc/systemd/system/sockets.target.wants/docker.socket
docker.socket:
[Unit]
Description=Docker Socket for the API
[Socket]
ListenStream=/var/run/docker.sock
SocketMode=0660
SocketUser=YOUR_USERNAME_HERE
SocketGroup=docker
[Install]
WantedBy=sockets.target
sudo systemctl restart docker
.
Rebooting the machine worked for me.
$ reboot
This work for me:
Get inside the container and modify the file's ACL
sudo usermod -aG docker $USER
sudo setfacl --modify user:$USER:rw /var/run/docker.sock
It's a better solution than use chmod.
lightdm and kwallet ship with a bug that seems to not pass the supplementary groups at login. To solve this, I also, beside sudo usermod -aG docker $USER
, had to comment out
auth optional pam_kwallet.so
auth optional pam_kwallet5.so
to
#auth optional pam_kwallet.so
#auth optional pam_kwallet5.so
in /etc/pam.d/lightdm
before rebooting, for the docker-group to actually have effect.
bug: https://bugs.launchpad.net/lightdm/+bug/1781418 and here: https://bugzilla.redhat.com/show_bug.cgi?id=1581495
use this command
sudo usermod -aG docker $USER
then restart your computer this worked for me.
you can follow these steps and this will work for you:
create a docker group sudo groupadd docker add your user to this group sudo usermod -aG docker $USER list the groups to make sure that docker group created successfully by running this command groups run the following command also to change the session for docker group newgrp docker change the group ownership for file docker.socksudo chown root:docker /var/run/docker.sock change the ownership for .docker directory sudo chown "$USER":"$USER" /home/"$USER"/.docker -R finally sudo chmod g+rwx "$HOME/.docker" -R
After that test you can run docker ps -a
chown
the docker.sock file.
i try this commend with sudo
commend and it was ok.sudo docker pull hello-world
or sudo docker run hello-world
The most straightforward solution is to type
sudo chmod 666 /var/run/docker.sock
every time you boot your machine. However, this method defeats any system security that may be in place and opens up the Docker socket to everybody. If this is acceptable to you -e.g.: the only user of your machine- then use it.
Nevertheless, it will be required every time you boot your machine, you can make it run with booting by adding
start on startup
task
exec chmod 666 /var/run/docker.sock
to the /etc/init/docker-chmod.conf
file.
666
Is excessive permissions. 660
or 640
should be more than enough
In the Linux environment, after installing docker
and docker-compose
reboot is required for work docker better to avoid this issue.
$ sudo systemctl restart docker
After Docker Installation on Centos. While running below command I got below error.
[centos@aiops-dev-cassandra3 ~]$ docker run hello-world
docker: Got permission denied while trying to connect to the Docker daemon socket at unix:///var/run/docker.sock: Post http://%2Fvar%2Frun%2Fdocker.soc k/v1.40/containers/create: dial unix /var/run/docker.sock: connect: permission denied.
See 'docker run --help'.
Change Group and Permission for docker.socket
[centos@aiops-dev-cassandra3 ~]$ ls -l /lib/systemd/system/docker.socket
-rw-r--r--. 1 root root 197 Nov 13 07:25 /lib/systemd/system/docker.socket
[centos@aiops-dev-cassandra3 ~]$ sudo chgrp docker /lib/systemd/system/docker.socket
[centos@aiops-dev-cassandra3 ~]$ sudo chmod 666 /var/run/docker.sock
[centos@aiops-dev-cassandra3 ~]$ ls -lrth /var/run/docker.sock
srw-rw-rw-. 1 root docker 0 Nov 20 11:59 /var/run/docker.sock
[centos@aiops-dev-cassandra3 ~]$
Verify by using below docker command
[centos@aiops-dev-cassandra3 ~]$ docker run hello-world
Unable to find image 'hello-world:latest' locally
latest: Pulling from library/hello-world
1b930d010525: Pull complete
Digest: sha256:c3b4ada4687bbaa170745b3e4dd8ac3f194ca95b2d0518b417fb47e5879d9b5f
Status: Downloaded newer image for hello-world:latest
Hello from Docker!
This message shows that your installation appears to be working correctly.
To generate this message, Docker took the following steps:
1. The Docker client contacted the Docker daemon.
2. The Docker daemon pulled the "hello-world" image from the Docker Hub.
(amd64)
3. The Docker daemon created a new container from that image which runs the
executable that produces the output you are currently reading.
4. The Docker daemon streamed that output to the Docker client, which sent it
to your terminal.
To try something more ambitious, you can run an Ubuntu container with:
$ docker run -it ubuntu bash
Share images, automate workflows, and more with a free Docker ID:
https://hub.docker.com/
For more examples and ideas, visit:
https://docs.docker.com/get-started/
[centos@aiops-dev-cassandra3 ~]$
After you installed docker, created 'docker' group and added user to it, edit docker service unit file:
sudo nano /usr/lib/systemd/system/docker.service
Add two lines into the section [Service]:
SupplementaryGroups=docker
ExecStartPost=/bin/chmod 666 /var/run/docker.sock
Save the file (Ctrl-X, y, Enter)
Run and enable the Docker service:
sudo systemctl daemon-reload
sudo systemctl start docker
sudo systemctl enable docker
I ran into a similar problem as well, but where the container I wanted to create needed to mount /var/run/docker.sock as a volume (Portainer Agent), while running it all under a different namespace. Normally a container does not care about which namespace it is started in -- that is sort of the point -- but since access was made from a different namespace, this had to be circumvented.
Adding --userns=host
to the run command for the container enabled it to use the attain the correct permissions.
Quite a specific use case, but after more research hours than I want to admit I just thought I should share it with the world if someone else ends up in this situation :)
It is definitely not the case the question was about, but as it is the first search result while googling the error message, I'll leave it here.
First of all, check if docker service is running using the following command:
systemctl status docker.service
If it is not running, try starting it:
sudo systemctl start docker.service
... and check the status again:
systemctl status docker.service
If it has not started, investigate the reason. Probably, you have modified a config file and made an error (like I did while modifying /etc/docker/daemon.json
)
The Docker daemon binds to a Unix socket instead of a TCP port. By default that Unix socket is owned by the user root and other users can only access it using sudo. The Docker daemon always runs as the root user.
If you don’t want to preface the docker command with sudo, create a Unix group called docker and add users to it. When the Docker daemon starts, it creates a Unix socket accessible by members of the docker group.
To create the docker group and add your user:
Create the docker group sudo groupadd docker Add your user to the docker group sudo usermod -aG docker $USER Log out and log back in so that your group membership is re-evaluated. If testing on a virtual machine, it may be necessary to restart the virtual machine for changes to take effect. On a desktop Linux environment such as X Windows, log out of your session completely and then log back in. On Linux, you can also run the following command to activate the changes to groups: newgrp docker Verify that you can run docker commands without sudo. The below command downloads a test image and runs it in a container. When the container runs, it prints an informational message and exits docker run hello-world
If you initially ran Docker CLI commands using sudo before adding your user to the docker group, you may see the following error, which indicates that your ~/.docker/ directory was created with incorrect permissions due to the sudo commands.
WARNING: Error loading config file: /home/user/.docker/config.json -
stat /home/user/.docker/config.json: permission denied
To fix this problem, either remove the ~/.docker/ directory (it is recreated automatically, but any custom settings are lost), or change its ownership and permissions using the following commands:
sudo chown "$USER":"$USER" /home/"$USER"/.docker -R
sudo chmod g+rwx "$HOME/.docker" -R
All other post installation steps for docker on linux can be found here https://docs.docker.com/engine/install/linux-postinstall/
I tried all the described methods and nothing helped to solve the problem. The solution was to use the --use-drivers parameter when running selenoid and selenoid-ui. Below is the full listing of my Dockerfile.
FROM selenoid/chrome
USER root
RUN apt-get update
RUN apt-get -y install docker.io
RUN curl -s https://aerokube.com/cm/bash | bash
RUN ./cm selenoid start --vnc --use-drivers
RUN ./cm selenoid-ui start --use-drivers
EXPOSE 4444 8080
CMD ["-conf", "/etc/selenoid/browsers.json", "-video-output-dir", "/opt/selenoid/video/"]
In my case it was the process itself (CI server agent) that was trying to run a docker command wasn't able to run it, but when I tried to run same command from within the same user it worked.
Restarting the daemon that runs CI server agent solved the problem.
The reason why command wasn't working from within agent before is because the agent was running before I installed docker and granted docker group permissions, and agent process used cached old permissions and was failing. Restarting the process dropped the cache and make things work out.
just open terminal and type this command
sudo chmod 666 /var/run/docker.sock
sudo chmod 666 /var/run/docker.sock
this helped me while i was getting error even to log in to the docker But now this works completely fine in my system.
Success story sharing
sudo systemctl restart docker
docker
group essentially grants root access, without enforcing regular sudo policies & auditing. See GitHub issue #9976 for details and discussion.