pkg/testutils: utility functions to facilitate writing Go tests

Docker-DCO-1.1-Signed-off-by: Solomon Hykes <solomon@docker.com> (github: shykes)
Add Cristian as maintainer to pkg/testutils

Docker-DCO-1.1-Signed-off-by: Solomon Hykes <solomon@docker.com> (github: shykes)
Fix format in maintainers files

Docker-DCO-1.1-Signed-off-by: Solomon Hykes <solomon@docker.com> (github: shykes)
Added note in manpages to clarify effect of docker start on started container

When run on a container that is already running, docker always succeeds.
This was an intentional change in v0.10; it previously caused an error.
This commit clarifies the man pages to indicate this is intended behavior.

Docker-DCO-1.1-Signed-off-by: Matthew Heon <mheon@redhat.com> (github: mheon)
Initial links for Docker Hub rename

Docker-DCO-1.1-Signed-off-by: James Turnbull <james@lovedthanlost.net> (github: jamtur01)
pkg/units: Add FromHumanSize

This does the "reverse" of HumanSize, i.e. maps a string to an int64
using SI prefixes for the extension.

Docker-DCO-1.1-Signed-off-by: Alexander Larsson <alexl@redhat.com> (github: alexlarsson)
devmapper: Fail init with ErrNotSupported if simple devmapper call fails

If we can't even get the current device mapper driver version, then
we cleanly fail the devmapper driver as not supported and fall back
on the next one.

Docker-DCO-1.1-Signed-off-by: Alexander Larsson <alexl@redhat.com> (github: alexlarsson)
Add --storage-opt graph driver option and pass through to driver

This lets you add storage specific options for the daemon.

Docker-DCO-1.1-Signed-off-by: Alexander Larsson <alexl@redhat.com> (github: alexlarsson)
devmapper: Add --storage-opt options for basic devicemapper settings

This allows setting these settings to be passed:
dm.basesize
dm.loopdatasize
dm.loopmetadatasize

Docker-DCO-1.1-Signed-off-by: Alexander Larsson <alexl@redhat.com> (github: alexlarsson)
devicemapper: Probe what filesystem to use when mounting

Docker-DCO-1.1-Signed-off-by: Alexander Larsson <alexl@redhat.com> (github: alexlarsson)
devmapper: Allow specifying filesystem for thin devices

This adds the following --storage-opts for the daemon:
dm.fs: The filesystem to use for the base image
dm.mkfsarg: Add an argument to the mkfs command for the base image
dm.mountopt: Add a mount option for devicemapper mount

Currently supported filesystems are xfs and ext4.

Docker-DCO-1.1-Signed-off-by: Alexander Larsson <alexl@redhat.com> (github: alexlarsson)
devmapper: Add options for specifying block devices

This adds dm.datadev and dm.metadatadev options that you can use with
--storage-opt to set to specific devices to use for the thin
provisioning pool.

Docker-DCO-1.1-Signed-off-by: Alexander Larsson <alexl@redhat.com> (github: alexlarsson)
devmapper: Add blkdiscard option and disable it on raw devices

The blkdiscard hack we do on container/image delete is pretty slow, but
required to restore space to the "host" root filesystem. However, it
is pretty useless on raw devices, and you may not need it in development
either.

In a simple test of the devicemapper backend on loopback the time to
delete 20 container went from 11 seconds to 0.4 seconds with
--storage-opt blkdiscard=false.

Docker-DCO-1.1-Signed-off-by: Alexander Larsson <alexl@redhat.com> (github: alexlarsson)
Fixes broken ssh server example

Docker-DCO-1.1-Signed-off-by: cpuguy83 <cpuguy83@gmail.com> (github: cpuguy83)
Clarify effect of docker start on started container in CLI docs

This behavior changed from v0.9 to v0.10, so document it to prevent
any confusion.

Docker-DCO-1.1-Signed-off-by: Matthew Heon <mheon@redhat.com> (github: mheon)
only forward auth to trusted locations

Docker-DCO-1.1-Signed-off-by: Victor Vieux <vieux@docker.com> (github: vieux)
Update nsinit to be nicer to work with and test
Docker-DCO-1.1-Signed-off-by: Michael Crosby <michael@crosbymichael.com> (github: crosbymichael)
Update for nsenter
Docker-DCO-1.1-Signed-off-by: Michael Crosby <michael@crosbymichael.com> (github: crosbymichael)
Merge pull request #6220 from vieux/fix_redirect

Only forward auth to trusted locations
Merge pull request #6156 from jamtur01/links

Initial link update for Docs