Setup devtmpfs and /dev for autodev bind mounts.

If autodev is not specifically set to 0 or 1, attempts to determine if
systemd is being utilized and forces autodev=1 to prevent host system
conflicts and collisions.

If autodev is enabled and the host /dev is mounted with devtmpfs
or /dev/.lxc is mounted with another file system...

Each container created by a privileged user gets a /dev directory
mapped off the host /dev here:

	/dev/.lxc/${name}.$( hash $lxcpath/$name )

Each container created by a non-privileged user gets a /dev/directory
mapped off the host /dev here:

	/dev/.lxc/user/${name}.$( hash $lxcpath/$name )

The /dev/.lxc/user is mode 1777 to allow unpriv access.

The /dev/.lxc/{containerdev} is bind mounted into the container /dev.

Fallback on failure is to mount tmpfs into the container /dev.

A symlink is created from $lxcpath/$name/rootfs.dev back to the /dev
relative directory to provid a code consistent reference for updating
container devs.

Signed-off-by: Michael H. Warfield <mhw@WittsEnd.com>
Signed-off-by: Serge Hallyn <serge.hallyn@ubuntu.com>
lxcapi_clone: set the right environment variable for mounted fs

If the container is dir-backed, we don't actually mount it (to
support unprivileged use).  So always set the LXC_ROOTFS_MOUNT
to bdev->dest, not to the rootfs path specified in the container
configuration.

This should fix bug http://pad.lv/1253573

Signed-off-by: Serge Hallyn <serge.hallyn@ubuntu.com>
Acked-by: Stéphane Graber <stgraber@ubuntu.com>
Support files for systemd on Fedora.

Added a file "lxc.service" for a systemd service file.

Added a file "lxc-devsetup" to setup /dev/ on startup to support autodev
in containers.

Service file references lxc-devsetup as an ExecStartPre command.  The
lxc-devsetup script is not dependent on systemd or Fedora and can
be used at bootup on any system.

Modified lxc.spec.in to install the two new files on Fedora.  The systemd
specific code in the lxc.spec file may need some review and conditionalize
for systemd on non-systemd rpm-based systems.

Signed-off-by: Michael H. Warfield <mhw@WittsEnd.com>
Signed-off-by: Serge Hallyn <serge.hallyn@ubuntu.com>
lxc_usernsexec: fix build breakage

Signed-off-by: Serge Hallyn <serge.hallyn@ubuntu.com>