Bug 1557048

Description of problem:
In both RHEL and Fedora, the docker daemon is not able to accept simultaneous requests to create docker networks.  I first observed this behavior in the drone CI software [1], which uses separate docker networks for each task in a matrix build.  One of the matrix tasks will succeed, but the others will fail with this error:

Error response from daemon: unable to remove jump to DOCKER-ISOLATION rule in FORWARD chain: (COMMAND_FAILED: '/usr/sbin/iptables -w2 -D FORWARD -j DOCKER-ISOLATION' failed: iptables: No chain/target/match by that name. )

I was also able to reproduce this error just by simultaneously running multiple `docker network create ...` commands via tmux synchronized panes (see Steps to Reproduce).


Version-Release number of selected component (if applicable):
docker-1.13.1-53.git774336d.el7
docker-1.13.1-44.git584d391.fc27


How reproducible:
Always when multiple commands are run simultaneously.  Not reproducible when only one command is run.


Steps to reproduce:
1. start tmux session
2. tmux command: split-window
3. in each pane, type `docker network create ...` with a unique network name
4. tmux command: set-window-option synchronize-panes
5. hit enter


Actual results:
One network is created, the other fails.


Expected results:
Both networks be created.


How to fix:
I was able to track this down to an upstream issue [2], which has already been fixed in docker/libnetwork and bundled in with docker 17.04.  It boils down to this commit [3] from docker/libnetwork#1658 [4].  I created a patch [5] based on that commit, and it applies cleanly to the RHEL SRPM and produces RPMS [6] that do not suffer from this bug.  I'm happy to send this patch as a pull request directly into projectatomic/docker if so desired.


Additional info:
[1]: https://discourse.drone.io/t/matrix-builds-network-concurrency-issue/1936
[2]: https://github.com/moby/moby/issues/25393
[3]: https://github.com/docker/libnetwork/commit/fe741120dbacc1c720a80812de1d65811695f5d6
[4]: https://github.com/docker/libnetwork/pull/1658
[5]: https://github.com/carlwgeorge/docker/commit/660a257754ab0e43e1e778baf8a625f1542fd334
[6]: https://copr.fedorainfracloud.org/coprs/carlwgeorge/docker/