When plugins have a positive refcount, they were not allowed to be
removed. However, plugins could still be disabled when volumes
referenced it and containers using them were running.
This change fixes that by enforcing plugin refcount during disable.
A "force" disable option is also added to ignore reference refcounting.
Signed-off-by: Anusha Ragunathan <anusha@docker.com>
This fix tries to address the issue raised on 29185 where
`docker inspect <unknown object>` on Windows will return:
```
Error response from daemon: plugins are not supported on this platform
```
The reason was that in case `--type` is not specified, `docker inspect`
will iterate through different types `container`, `image`, `network`,
`plugin` etc. The `plugin` object is the last type to check.
However, as `plugin` is not supported on Windows yet, the error message
is not very informative for `plugins are not supported on this platform`.
This fix tries to fix the issue by return a `not found` error on unsupported
platforms as well.
An integration test has been added to cover the changes for Windows/Linux.
This fix fixes 29185.
Signed-off-by: Yong Tang <yong.tang.github@outlook.com>
