Unable to execute docker sibling

[jmkgreen]

We seem unable to use the host's docker machine (v1.7.1) when operating without root privileges.

On the host I have added a jenkins user (resultant id:1006) and group and added it to the docker group:

jenkins@virt-04:/home/jamesg$ id
uid=1006(jenkins) gid=1007(jenkins) groups=1007(jenkins),4(adm),998(docker),1002(admin)

And a corresponding folder owned by that user. I launch jenkins passing in our --username 1006 and bind-mounting our folder into /var/jenkins_home.

This appears to work well enough. I also bind-mount /var/run/docker.sock and /usr/bin/docker. Inside the Jenkins container I can execute docker help and see assistance. If I run docker ps I get told permission denied:

jenkins@79798524d818:/$ docker ps
Get http:///var/run/docker.sock/v1.19/containers/json: dial unix /var/run/docker.sock: permission denied. Are you trying to connect to a TLS-enabled daemon without TLS?

Within a job, the following is the relevant console log:

+ pwd
/var/jenkins_home/jobs/dispatcher/workspace
ERROR: Failed to mkdirs: ?/.docker

If I docker exec in to the container with --user root I can repeat docker ps and see the listing of sibling containers.

If I launch the Jenkins docker container with --username root instead of --username 1006, Jenkins is now able to launch sibling docker containers.

I do not expect this problem to be exclusive to Jenkins, but the problem ought to be documented. Nor do I know what I've missed...

[carlossg]

Seems to me that the HOME of your jenkins user is not set, and it is trying to create the .docker dir in the wrong path ?/.docker

[jmkgreen]

That's pretty much where I landed. So I tried making the host's jenkins have a home dir of /var/lib/jenkins_home, and of /mnt/jenkins which is the host point. Neither worked.

To get some work done, I launched with root and saw success.

[dweomer]

This isn't a docker-machine issue, it is a docker client accessing the daemon issue yes? What you have is a permissions problem for the jenkins user with regards to the /var/run/docker.sock. Please take a look at the script i mention in this comment #196 (comment) for #196.