External volumes are created and managed by the user.
They are not namespaced.
They are expected to exist at the beginning of the up phase.
Signed-off-by: Joffrey F <joffrey@docker.com>
During the initialize_volumes phase, if a volume using the
non-namespaced name already exists, don't create the namespaced
equivalent.
Signed-off-by: Joffrey F <joffrey@docker.com>
When created through the compose file, volumes are prefixed
with the name of the project they belong to + underscore,
similarly to how containers are currently handled.
Signed-off-by: Joffrey F <joffrey@docker.com>