Closes#1862
This adds a new rpc to the introspection service to provide server
information with a generated UUID that is done on demand and the os and
arch of the server.
ctr output:
```bash
> sudo ctr version
Client:
Version: v1.2.0-802-g57821695.m
Revision: 578216950de9c1c188708369e2a31ac6c494dfee.m
Server:
Version: v1.2.0-802-g57821695.m
Revision: 578216950de9c1c188708369e2a31ac6c494dfee.m
UUID: 92e982a9-f13e-4a2c-9032-e69b27fed454
OS: linux
ARCH: amd64
```
Signed-off-by: Michael Crosby <crosbymichael@gmail.com>
Because of a side-effect import, we have the possibility of pulling in
several unnecessary packages that are used by the plugin and not at
runtime to implement protobuf structures. Setting these imports to
`weak` prevents this from happening, reducing the total import set,
reducing memory usage and binary size.
Signed-off-by: Stephen J Day <stephen.day@docker.com>
After several requests for information about platform support,
configuration introspection and feature switches, we now have a solution
that should work in all these use cases. The Introspection API hooks
into the plugin subsystem registration process. During registration,
plugins declare several pieces of information, allowing clients to
discover the cababilities and support that a containerd instance
provides, including whether or not it loaded with an error.
To allow symmetrical error reporting, the `google/rpc.Status` protobuf
definitions have been brought in from the googleapis project.
Unfortunately, we had to generate these in place to match our protobuf
system.
Once we like this design, we can add an implementation to integrate it
directly with the plugin system.
Enjoy!
Signed-off-by: Stephen J Day <stephen.day@docker.com>
