I tried installing the docker using the linux method.
However when the command $docker run hello-world is executed, it outputs:
docker: Cannot connect to the Docker daemon. Is the docker daemon running on this host?.
See 'docker run --help'.
What can be done about this?
First of all make sure the daemon is running:
$ps aux|grep "docker daemon"|grep -v "grep"
A) The daemon is not launched (no lines are returned by the ps)
Start the daemon that is not working:
$sudo /usr/bin/docker daemon -H unix:///var/run/docker.sock
Or start it as a service with:
$sudo /usr/sbin/service docker start
At this point the daemon is launched.
B) The daemon is launched
As shown by the ps with something like:
[..] /usr/bin/docker daemon -H unix:///var/run/docker.sock
You're good to go with your first container with a:
$sudo docker run hello-world.
sudo and docker
If you want to use docker without being sudo (this you should, though you must be aware of the security warning!) a good read of this will help you.
You have to run this command as sudo.
sudo docker run hello-world
This will give you enough privileges to perform that action.
If you want to enable your user to rung docker without sudo, then check out this answer.
Related
Even though my user is on docker group and I can launch docker without sudo, and I'm running idea.sh from my user, whenever I try to connect to docker from within Intellij Idea docker plugin, I get
Cannot connect to the Docker daemon at unix:///var/run/docker.sock. Is the docker daemon running?
I'm trying the Unix socket method. I already tried multiple restarts and logout.
I'm on Ubuntu 20.04 and Intellijd Idea 2020.3
Adding current user to docker group worked for me:
sudo gpasswd -a ${USER} docker
You might need to create group first:
sudo groupadd docker
restart your OS after those changes
For me it work
sudo chmod 0777 /var/run/docker.sock
Then test this in the terminal without the sudo
docker ps -a
normally you should have access to the docker process
I want to open my Docker server up for others to access, before the attempt to do so, I shut the current daemon down.
$ sudo service docker stop
Once the Docker daemon has been stopped, I tried to restart it manually and open it
up to outside users with the following command.
$ sudo docker daemon -H tcp://0.0.0.0:2375
What I get is
I tried with -d instead of daemon, still the same.
My current docker version is Docker version 18.09.2, build 6247962
I got the following error when I run docker. Does anybody know how to fix the problem. The OS is Mac OS X.
$ docker --version
Docker version 17.12.0-ce, build c97c6d6
$ docker run hello-world
docker: Cannot connect to the Docker daemon at unix:///var/run/docker.sock. Is the docker daemon running?.
See 'docker run --help'.
You can restart Docker with the following
Stop Docker for Mac gracefully
Stop all Docker containers without confirmation (make sure nothing is running in Docker)
docker ps -q | xargs -L1 docker stop
Requires all Docker containers are stopped
test -z "$(docker ps -q 2>/dev/null)" && osascript -e 'quit app "Docker"'
Start Docker gracefully
open --background -a Docker
I just found out that I have to restart my docker desktop as well. I had no idea that docker desktop and terminal's docker command are related. But now, apparently, they are related. If anyone encounters similar problems, remember to try restart your docker desktop and wait for it to get running!
I have a simple Ubuntu 16.10 container which has docker.io installed.
The docker process terminates after it starts and log has this information. Any troubleshooting suggestions?
$ docker run -it --name dcos-ubuntu-python5 python-docker /bin/bash
root#5ff6bb6b6dc7:/# docker run hello-world
docker: Cannot connect to the Docker daemon. Is the docker daemon running on this host?.
See 'docker run --help'.
root#5ff6bb6b6dc7:/# service docker start
* Starting Docker: docker [ OK ]
root#5ff6bb6b6dc7:/# service docker status
* Docker is not running
root#5ff6bb6b6dc7:/# tail -f /var/log/docker.log
time="2017-12-21T17:09:45.464736873Z" level=info msg="libcontainerd: new containerd process, pid: 50"
time="2017-12-21T17:09:46.472578239Z" level=fatal msg="Error starting daemon: error initializing graphdriver: operation not permitted"
Why do you want to run docker within docker container?
Docker-in-Docker is developed to help docker development. And it needs --privileged flag to run docker container.(Please read jpetazzo's blog here.)
If you really want to execute docker in docker container, you also have other options.
Bind mount docker.sock. Some people call this DooD(Docker-outside-of-Docker)
docker run -v /var/run/docker.sock:/var/run/docker.sock ...
Install docker(client) and specify DOCKER_HOST to access remote docker daemon. Be careful about socket protection with certificates.
Are you running docker as sudo if not run as sudo or
Else add user group to docker
docker group. For this run following command:
sudo usermod -aG docker $USER
The answer was simple.
docker run -it --privileged --name dcos-ubuntu-python5 python-docker /bin/bash
(This was also mentioned partly in #SunghoMoon's response. So Credits to him).
I am trying to run my Docker commands, but I am facing the notification error in the title. I tried running:
ps auxww | grep docker
but still getting the error. Any solution?
If you can verify that the docker daemon is running then it may be that your user is not allowed to access docker.
To do this add yourself to the docker group.
sudo usermod -aG docker <userid>
Remember to do a re-login or otherwise apply/activate the new group permission.
newgrp docker
How about launching the daemon
sudo service docker start
should do the trick.
Or
sudo docker -d
In my case I had multiple docker instances running so it didn't know what to attach to. After killing them and restarting, my problem was solved.