Support hairpin NAT

This re-applies commit b39d02b with additional iptables rules to solve the issue with containers routing back into themselves.

The previous issue with this attempt was that the DNAT rule would send traffic back into the container it came from. When this happens you have 2 issues.
1) reverse path filtering. The container is going to see the traffic coming in from the outside and it's going to have a source address of itself. So reverse path filtering will kick in and drop the packet.
2) direct return mismatch. Assuming you turned reverse path filtering off, when the packet comes back in, it's goign to have a source address of itself, thus when the reply traffic is sent, it's going to have a source address of itself. But the original packet was sent to the host IP address, so the traffic will be dropped because it's coming from an address which the original traffic was not sent to (and likely with an incorrect port as well).

The solution to this is to masquerade the traffic when it gets routed back into the origin container. However for this to work you need to enable hairpin mode on the bridge port, otherwise the kernel will just drop the traffic.
The hairpin mode set is part of libcontainer, while the MASQ change is part of docker.

This reverts commit 63c303eecdbaf4dc7967fd51b82cd447c778cecc.

Docker-DCO-1.1-Signed-off-by: Patrick Hemmer <patrick.hemmer@gmail.com> (github: phemmer)
Not fail on updating parent links

Fixes #8796

Signed-off-by: Alexandr Morozov <lk4d4@docker.com>
Fix Docker Hub tags list specification

The current implementation of the Docker Hub returns a list of objects
containing the tag name and the layer id.

Docker-DCO-1.1-Signed-off-by: Vincent Giersch <vincent.giersch@ovh.net>
pkg/mount: mountinfo from specified pid

Signed-off-by: Vincent Batts <vbatts@redhat.com>
Merge pull request #8931 from vbatts/vbatts-mount_pid_mountinfo

pkg/mount: mountinfo from specified pid
Revise Docs Maintainers list

Removing Sonat from docs maintainers because he no longer has time to complete all the responsibilities. Many thanks to Sonat for his help.

Docker-DCO-1.1-Signed-off-by: Fred Lifton <fred.lifton@docker.com> (github: fredlf)
Use the HTTP Last-Modified http header as the mtime value for ADD cmd when present

Closes #8331

Signed-off-by: Doug Davis <dug@us.ibm.com>
vendor: update vendor'd libcontainer version

This patch updates the vendor'd libcontainer version, so that Docker can
take advantage of the updates to the `user` API.

Signed-off-by: Aleksa Sarai <cyphar@cyphar.com> (github: cyphar)
*: transition to new libcontainer/user API

This patch fixes the compilation errors in Docker due to changes in the
libcontainer/user API. There is no functionality change due to this
patch.

Signed-off-by: Aleksa Sarai <cyphar@cyphar.com> (github: cyphar)
Merge pull request #9023 from cyphar/libcontainer-update-to-new-interface

Update vendor'd `libcontainer` and update to use new `user` interface.
pkg/namesgenerator: add Yeong-Sil Jang

Docker-DCO-1.1-Signed-off-by: Cristian Staretu <cristian.staretu@gmail.com> (github: unclejack)
Remove the redundant stripComment.

Signed-off-by: xuzhaokui <cynicholas@gmail.com>
Additional info for docker binary
Signed-off-by: Prasanna Gautam <prasannagautam@gmail.com>

I found that certain docker installations do not handle binding to the source directory quite right. Just writing it based on help from backjlack and tibor in IRC.
Fix typo in Docker Links chapter of User Guide
Fix mkdir typo in dockerfile_best-practices.md.
limiting to 80 chars

Signed-off-by: Prasanna Gautam < prasannagautam@gmail.com >
Merge pull request #9029 from ovh/fix/doc

Fix Docker Hub tags list specification
Merge pull request #9057 from andi5/typo-best-practices

Fix mkdir typo in dockerfile_best-practices.md.
Merge pull request #9052 from andreyst/master

Fix typo in Docker Links chapter of User Guide
Remove the redundant include_search in mkdocs.yml