This patch introduces a new experimental engine-level plugin management
with a new API and command line. Plugins can be distributed via a Docker
registry, and their lifecycle is managed by the engine.
This makes plugins a first-class construct.
For more background, have a look at issue #20363.
Documentation is in a separate commit. If you want to understand how the
new plugin system works, you can start by reading the documentation.
Note: backwards compatibility with existing plugins is maintained,
albeit they won't benefit from the advantages of the new system.
Signed-off-by: Tibor Vass <tibor@docker.com>
Signed-off-by: Anusha Ragunathan <anusha@docker.com>
Check if there is a plugin socket first under `/run/docker/plugins/NAME.sock`.
If there is no socket for a plugin, check `/etc/docker/plugins/NAME.spec` and
`/usr/lib/docker/plugins/NAME.spec` for spec files.
Signed-off-by: David Calavera <david.calavera@gmail.com>
