Re: [atomic-devel] Shared mounts in Atomic Host

[Daniel J Walsh <dwalsh redhat com>]

On 03/16/2016 12:35 PM, Dusty Mabe wrote:
> On 03/16/2016 12:02 PM, Daniel J Walsh wrote:
> > On 03/16/2016 11:42 AM, Dusty Mabe wrote:
> > > On 03/16/2016 10:51 AM, Daniel J Walsh wrote:
> > > > On 03/16/2016 10:47 AM, Dusty Mabe wrote:
> > > > > I am using the updates-testing f23 atomic host that has docker 1.10. I
> > > > > want to have a shared mount between the host and a docker container.
> > > > >
> > > > > I'm trying to do it but I keep getting an error
> > > > >
> > > > > ```
> > > > > [vagrant vanilla-f23atomic ~]$ rpm -q docker
> > > > > docker-1.10.2-6.git0f5ac89.fc23.x86_64
> > > > > [vagrant vanilla-f23atomic ~]$ sudo atomic host status
> > > > >      TIMESTAMP (UTC)         VERSION   ID             OSNAME            REFSPEC
> > > > > * 2016-03-12 16:53:31     23.87     53e922e968     fedora-atomic     fedora-atomic:fedora-atomic/f23/x86_64/testing/docker-host
> > > > >      2016-03-16 00:49:16     23.84     b428a17d6f     fedora-atomic     fedora-atomic:fedora-atomic/f23/x86_64/docker-host
> > > > > [vagrant vanilla-f23atomic ~]$ sudo mount --make-shared /
> > > > > [vagrant vanilla-f23atomic ~]$ sudo docker run -it --privileged --rm -v /tmp/sharedfolder:/tmp/sharedfolder:shared sshfs /bin/bash
> > > > > docker: Error response from daemon: Cannot start container 7e99752dd8f2812a7d7acaa58594504be936b6f37aa77b6521a7098450343837: Path /tmp/sharedfolder is mounted on /sysroot but it is not a shared mount..
> > > > > ```
> > > > >
> > > > > I think this should work because this commit is in docker 1.10:
> > > > > https://github.com/docker/docker/pull/17034/commits
> > > > >
> > > > > Am I doing something wrong?
> > > > >
> > > > > Dusty
> > > > Did you turn off sharing in the docker unit file?
> > > I did not change anything but this is set in the docker unit file:
> > >
> > > [vagrant vanilla-f23atomic ~]$ rpm -qV docker | grep docker.service
> > > .......T.    /usr/lib/systemd/system/docker.service
> > > [vagrant vanilla-f23atomic ~]$ grep Mount /usr/lib/systemd/system/docker.service
> > > MountFlags=slave
> > >
> > > Dusty
> > Remove this line and reload and restart the unit file.
> So I changed it to 'shared' and it worked. What should be in the unit file? Is
> MoutFlags=slave what we want there or should I open a bug?
>
> Dusty
We want nothing in there.  The reason this was originally added was for 
performance
when running hundreds of containers.  I do not believe this is needed 
any longer.

If you installed docker-1.10, it should have updated the service file 
and removed this flag.

If the flag is still there, it is a bug in docker-1.10.