Don't create source directory while the daemon is being shutdown

[TomSweeneyRedHat]

Signed-off-by: TomSweeneyRedHat tsweeney@redhat.com

• What I did

Ported the patch from moby#33330 into this branch. The problem is the /var/run/docker.sock file can with the right conditions and bad timing be created as a directory rather than a link when the daemon is shutting down. Without this change docker would not restart after this timing issue hit until the /var/run/docker.sock directory was removed.

This is the second part, #327 addressed Docker-1.13.1

• How I did it

vi is my friend.

• How to verify it
  The easiest way unfortunately calls for a code change. Please reference the test methodology in Don't create source directory while the daemon is being shutdown, fix #30348 moby/moby#33330. The file daemon/oci_linux.go needs to be modified and then docker needs to be compiled and installed after the modification.

• Description for the changelog
  Don't create /var/run/docker.sock as a directory when the daemon is shutting down

** - Testing:

[root@localhost run]# systemctl start docker
[root@localhost run]# docker run -ti --restart always -v /var/run/docker.sock:/sock alpine
/ # exit
[root@localhost run]# systemctl stop docker
[root@localhost run]# systemctl start docker
[root@localhost run]# docker run -ti --restart always -v /var/run/docker.sock:/sock alpine
/ # exit
[root@localhost run]# systemctl stop docker
[root@localhost run]# systemctl start docker
[root@localhost run]# ls -alF docker.sock
srw-rw----. 1 root root 0 Oct 10 19:47 docker.sock=

From journalctl with the new log entry showing that the error condition is being handled correctly:

Oct 10 19:46:46 localhost.localdomain dockerd-current[4884]: time="2018-10-10T19:46:46.51

[TomSweeneyRedHat]

@runcom tested again, reviewed again, gtg. Thanks again for the cherry-pick thought.

[TomSweeneyRedHat]

Addresses: https://bugzilla.redhat.com/show_bug.cgi?id=1466479