Adds 2 new methods to v2 plugin `Acquire` and `Release` which allow
refcounting directly at the plugin level instead of just the store.
Since a graphdriver is initialized exactly once, and is really managed
by a separate object, it didn't really seem right to call
`getter.Get()` to refcount graphdriver plugins.
On shutdown it was particularly weird where we'd either need to keep a
driver reference in daemon, or keep a reference to the pluggin getter in
the layer store, and even then still store extra details on if the
graphdriver is a plugin or not.
Instead the plugin proxy itself will handle calling the neccessary
refcounting methods directly on the plugin object.
Also adds a new interface in `plugingetter` to account for these new
functions which are not going to be implemented by v1 plugins.
Changes terms `plugingetter.CREATE` and `plugingetter.REMOVE` to
`ACQUIRE` and `RELEASE` respectively, which seems to be better
adjectives for what we're doing.
Signed-off-by: Brian Goff <cpuguy83@gmail.com>
Legacy plugins expect host-relative paths (such as for Volume.Mount).
However, a containerized plugin cannot respond with a host-relative
path. Therefore, this commit modifies new volume plugins' paths in Mount
and List to prepend the container's rootfs path.
This introduces a new PropagatedMount field in the Plugin Config.
When it is set for volume plugins, RootfsPropagation is set to rshared
and the path specified by PropagatedMount is bind-mounted with rshared
prior to launching the container. This is so that the daemon code can
access the paths returned by the plugin from the host mount namespace.
Signed-off-by: Tibor Vass <tibor@docker.com>
plugingetter is indepedent of docker/docker packages, so it can be
moved to pkg. This is also necessary for authorization plugins (part of
pkg) to use pluginv2. The original path at plugin/getter will be
eventually removed, when external repos (eg. libnetwork) update their
import paths.
Signed-off-by: Anusha Ragunathan <anusha@docker.com>
allencloud