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>
v2/Plugin struct had fields that were
- purely used by the manager.
- unsafely exposed without proper locking.
This change fixes this, by moving relevant fields to the manager as well
as making remaining fields as private and providing proper accessors for
them.
Signed-off-by: Anusha Ragunathan <anusha@docker.com>
In the plugin manifest, Capabilities has been moved to
Linux.Capabilities to avoid confusion with Interface.Types[i].Capability
A DeviceCreation boolean has also been added to the manifest. This could
be changed in the future to be specific to a major number.
Signed-off-by: Tibor Vass <tibor@docker.com>
fmt package formats an error by calling its Error() method.
This results in recursion. Fix this. Also remove dead code.
Signed-off-by: Anusha Ragunathan <anusha@docker.com>
As part of making graphdrivers support pluginv2, a PluginGetter
interface was necessary for cleaner separation and avoiding import
cycles.
This commit creates a PluginGetter interface and makes pluginStore
implement it. Then the pluginStore object is created in the daemon
(rather than by the plugin manager) and passed to plugin init as
well as to the different subsystems (eg. graphdrivers, volumedrivers).
A side effect of this change was that some code was moved out of
experimental. This is good, since plugin support will be stable soon.
Signed-off-by: Anusha Ragunathan <anusha@docker.com>
Split plugin package into `store` and `v2/plugin`. Now the functionality
is clearly delineated:
- Manager: Manages the global state of the plugin sub-system.
- PluginStore: Manages a collection of plugins (in memory and on-disk)
- Plugin: Manages the single plugin unit.
This also facilitates splitting the global PluginManager lock into:
- PluginManager lock to protect global states.
- PluginStore lock to protect store states.
- Plugin lock to protect individual plugin states.
Importing "github.com/docker/docker/plugin/store" will provide access
to plugins and has lesser dependencies when compared to importing the
original monolithic `plugin package`.
Signed-off-by: Anusha Ragunathan <anusha@docker.com>
