Unlike `docker run -v..`, `docker service create --mount`
does not allow bind-mounting non-existing host paths.
This adds validation for the specified `source`, and
produces an error if the path is not found on the
host.
Signed-off-by: Sebastiaan van Stijn <github@gone.nl>
This is intended as a minor fix for 1.12.1 so that task creation doesn't
do unexpected things when the user supplies erroneous paths.
In particular, because we're currently using hostConfig.Binds to setup
mounts, if a user uses an absolute path for a volume mount source, or a
non-absolute path for a bind mount source, the engine will do the
opposite of what the user requested since all absolute paths are
treated as binds and all non-absolute paths are treated as named
volumes.
Fixes#25253
Signed-off-by: Brian Goff <cpuguy83@gmail.com>
