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 $USER
The answer was simple.
docker run -it --privileged --name dcos-ubuntu-python5 python-docker /bin/bash
(This was also mentioned partly in #SunghoMoon's response. So Credits to him).
Related
I'm setting up a new appveyor server and trying to build docker images with using the docker build feature. But when I try to run docker commands in my custom build container, got the error that shown below.
Cannot connect to the Docker daemon at unix:///var/run/docker.sock. Is the docker daemon running?
I think the appveyor server should run our custom build containers with the volume option that point the docker.sock.
sudo docker run --rm -it -v /var/run/docker.sock:/var/run/docker.sock -v /usr/bin/docker:/usr/bin/docker name-of-the-custom-image bash
You can modify Docker cloud settings under Account -> Build environment and put the following into Custom Docker command arguments:
-v /var/run/docker.sock:/var/run/docker.sock -v /usr/bin/docker:/usr/bin/docker
https://help.appveyor.com/discussions/problems/24364-how-to-run-docker-command-in-docker-container-for-appveyor-server-docker-builds
I am new here and I've been trying to install docker on Ubuntu but I have no clue where this error is coming from.
I followed the installation instruction for Ubuntu on Docker website, and everything is installed, except that running docker gives me an error message that says "docker: Cannot connect to the Docker daemon at unix:///var/run/docker.sock. Is the docker daemon running?.
See 'docker run --help'."
This is Ubuntu Bionix 18.04, and my laptop runs on Windows.
I tried running docker with "sudo service docker restart", but when I check the status with "sudo service docker status" after the restart command, it says Docker is not running.
msok0216#DESKTOP-3M5NTKP:/etc/systemd/system$ sudo service docker restart
* Starting Docker: docker [ OK ]
msok0216#DESKTOP-3M5NTKP:/etc/systemd/system$ sudo service docker status
* Docker is not running
msok0216#DESKTOP-3M5NTKP:/etc/systemd/system$ sudo service docker start
* Starting Docker: docker [ OK ]
msok0216#DESKTOP-3M5NTKP:/etc/systemd/system$ sudo service docker status
* Docker is running
msok0216#DESKTOP-3M5NTKP:/etc/systemd/system$ sudo 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'.
enter image description here
I'm running https://hub.docker.com/r/jenkinsci/blueocean/ in docker. Trying to build a docker image in jenkins.
but i get the following error:
Cannot connect to the Docker daemon at unix:///var/run/docker.sock. Is the docker daemon running?
clearly the jenkins version in docker does not have access to the docker binary.
I confirmed this by,
docker exec -it db4292380977 bash
docker images
Cannot connect to the Docker daemon at unix:///var/run/docker.sock. Is the docker daemon running?
"db4292380977" is the running container. It shows the same error.
Question:
how do I allow access to docker in the jenkins container?
The docker client is installed on the jenkinsci/blueocean image, but not the daemon. Docker client will use the daemon (by default via the socket unix:///var/run/docker.sock). Docker client needs a Docker daemon in order to work, you can read Docker Architecture for more info.
What you can do:
Use docker-in-docker (DinD) image
Library Docker image provides a way to run a Docker daemon in Docker, you can then use it from another container. For example, using plain docker CLI:
docker run --name docker-dind --privileged -d docker:stable-dind
docker run --name jenkins --link=docker-dind -d jenkinsci/blueocean
docker exec jenkins docker -H docker-dind images
REPOSITORY TAG IMAGE ID CREATED SIZE
Docker daemon runs in docker-dind container and can be reached using the same hostname. You just need to provide the docker client with the daemon host (-H docker-dind in the example, you can also use DOCKER_HOST env variable as described in the doc).
Mount host machine /var/run/docker.sock in your container
As described by #Herman Garcia answer:
docker run -p 8080:8080 --user root \
-v /var/run/docker.sock:/var/run/docker.sock jenkinsci/blueocean
You need to mount your local /var/run/docker.sock and run the container as root user
NOTE: this might be a security flaw so be careful who has access to the jenkins container
docker run -p 8080:8080 --user root \
-v /var/run/docker.sock:/var/run/docker.sock jenkinsci/blueocean
you will be able to execute docker inside the container
➜ ~ docker exec -it gracious_agnesi bash
bash-4.4# docker ps
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS
NAMES
c4dc85b0d88c jenkinsci/blueocean "/sbin/tini -- /usr/…" 18 seconds ago Up 16 seconds 0.0.0.0:8080->8080/tcp, 50000
/tcp gracious_agnesi
Just only try to do the same command but with sudo in the beginning
For example
sudo docker images
sudo docker exec -it db4292380977 bash
To avoid use sudo in the future you should run this command in Unix O.S
sudo usermod -aG docker <your-user>
Change for the user that you are using at this moment. Remember to log out and back in for this to take effect! More information about Docker installation click here
How to reboot centos in docker ?
I had pulled centos 7 from docker
use the 'shutdown -r now'
The console said 'Failed to talk to init daemon.'
I also used 'reboot -f' , and get the
'Rebooting.
Failed to reboot: Operation not permitted' for rsp
Why you want to restart container?
if it is necessary you can use
docker exec -it <container name> reboot
or you can stop container and start it again
docker stop -f <container name>
then
docker start <container name>
Assuming you are logged in to your container and trying to "reboot" the container:
e.g. docker run -i -t centos /bin/bash
and then reboot
You shouldn't do is.
Please use docker run/start/stop....
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.