Docker in Docker permissions error

Question

I have a docker in docker setup for CI. Essentially, the machine has a jenkins CI server on it that uses the same machines docker socket to create nodes for CI.

This was working great until I recently updated docker. I've identified the issue, but I can't seem to figure out the right magic to get it working.

host $ docker exec -it myjenkins bash
jenkins@container $ docker ps

Got permission denied while trying to connect to the Docker daemon 

socket at unix:///var/run/docker.sock: Get http://%2Fvar%2Frun%2Fdocker.sock/v1.26/containers/json: dial unix /var/run/docker.sock: connect: permission denied

host $ docker exec -it -u root -it myjenkins bash

root@container $ docker ps 

... docker ps from host container yay! ...

So here's what I surmise. I have access to the host docker socket from within the container, but I can't seem to give permission to the jenkins user.

I've added the docker group, and also added the jenkins user to the docker group. But I still get the same error. I've restarted a whack of times so, I'm kind of at a loss for what to do next.

Is there a way to force permissions for a user on a particular socket?

Answer 1

Personally, i've just had to do this :

sudo gpasswd -a $USER docker 

And it worked out