Edits and fixes to Dockerfile Best Practices based on review feedback.

Docker-DCO-1.1-Signed-off-by: Fred Lifton <fred.lifton@docker.com> (github: fredlf)
Create registry_api_client_libraries.md
Signed-off-by: Konrad Kleine <konrad.wilhelm.kleine@gmail.com>
Add registry_api_client_libraries.md to mkdocs.yml

Signed-off-by: Konrad Kleine <konrad.wilhelm.kleine@gmail.com>
registry: getting Endpoint ironned out

Signed-off-by: Vincent Batts <vbatts@redhat.com>
Update libtrust version

Updated to version of libtrust with the trust graph implementation

Signed-off-by: Derek McGowan <derek@mcgstyle.net> (github: dmcgowan)
Add provenance pull flow for official images

Add support for pulling signed images from a version 2 registry.
Only official images within the library namespace will be pull from the
new registry and check the build signature.

Signed-off-by: Derek McGowan <derek@mcgstyle.net> (github: dmcgowan)
Typo: changed "Maintainers" to "maintainers"

Signed-off-by: Konrad Kleine <konrad.wilhelm.kleine@gmail.com>
Edits and fixes to Dockerfile Best Practices based on review feedback.

Docker-DCO-1.1-Signed-off-by: Fred Lifton <fred.lifton@docker.com> (github: fredlf)
Add comment for permission and fix wrong format variable

Signed-off-by: Derek McGowan <derek@mcgstyle.net> (github: dmcgowan)
Make volume.Containers private

Also wrap access in mutex.
Makes sure we don't have any pontential for races in accessing this.
It also doesn't really need to be/shouldn't be in the config.json anyway

Docker-DCO-1.1-Signed-off-by: Brian Goff <bgoff@cpuguy83-mbp.home> (github: cpuguy83)
docs: Update `docker exec` examples

Signed-off-by: Fabio Rehm <fgrehm@gmail.com>
Add note to docs about lack of shell processing in JSON form

Closes #5509

Signed-off-by: Doug Davis <dug@us.ibm.com>
Merge pull request #8372 from cpuguy83/change_volume_containers_to_private

Make volume.Containers private
Merge pull request #8320 from dmcgowan/provenance_pull

Official image provenance pull flow
Merge pull request #8336 from kwk/improve_docs_with_note_about_registry_frontend_web_app

Improve docs with note about registry frontend web app
Fix #6231 - Accept chunked encoding on start

Docker-DCO-1.1-Signed-off-by: Brian Goff <cpuguy83@gmail.com> (github: cpuguy83)
Merge pull request #8324 from cpuguy83/6231_fix_chunked_encoding

Fix #6231 - Accept chunked encoding on start
Merge pull request #8375 from fgrehm/patch-2

docs: Update `docker exec` examples
Fixed a typo in "Installing Docker on Mac OS X"

evironment -> environment
Support for consistent MAC address.

Right now, MAC addresses are randomly generated by the kernel when
creating the veth interfaces.

This causes different issues related to ARP, such as #4581, #5737 and #8269.

This change adds support for consistent MAC addresses, guaranteeing that
an IP address will always end up with the same MAC address, no matter
what.

Since IP addresses are already guaranteed to be unique by the
IPAllocator, MAC addresses will inherit this property as well for free.

Consistent mac addresses is also a requirement for stable networking (#8297)
since re-using the same IP address on a different MAC address triggers the ARP
issue.

Finally, this change makes the MAC address accessible through docker
inspect, which fixes #4033.

Signed-off-by: Andrea Luzzardi <aluzzardi@gmail.com>