This means that plugins can use whatever methods the monolithic CLI supports,
which is good for consistency.
This relies on `os.Args[0]` being something which can be executed again to
reach the same binary, since it is propagated (via an envvar) to the plugin for
this purpose. This essentially requires that the current working directory and
path are not modified by the monolithic CLI before it launches the plugin nor
by the plugin before it initializes the client. This should be the case.
Previously the fake apiclient used by `TestExperimentalCLI` was not being used,
since `cli.Initialize` was unconditionally overwriting it with a real one
(talking to a real daemon during unit testing, it seems). This wasn't expected
nor desirable and no longer happens with the new arrangements, exposing the
fact that no `pingFunc` is provided, leading to a panic. Add a `pingFunc` to
the fake client to avoid this.
Signed-off-by: Ian Campbell <ijc@docker.com>
Previously a plugin which used these hooks would overwrite the top-level plugin
command's use of this hook, resulting in the dockerCli object not being fully
initialised.
Provide a function which plugins can use to chain to the required behaviour.
This required some fairly ugly arrangements to preserve state (which was
previously in-scope in `newPluginCOmmand`) to be used by the new function.
Signed-off-by: Ian Campbell <ijc@docker.com>
That is, the helper to be used from the plugin's `main`.
Also add a `helloworld` plugin example and build integration.
Signed-off-by: Ian Campbell <ijc@docker.com>
Ian Campbell