Update server with nri injection points

This allows development with container to be done for NRI without the need for
custom builds.

This is an experimental feature and is not enabled unless a user has a global
`/etc/nri/conf.json` config setup with plugins on the system.  No NRI code will
be executed if this config file does not exist.

Signed-off-by: Michael Crosby <michael@thepasture.io>

vendor/github.com/containerd/nri/client.go

@@ -46,6 +46,8 @@ type Client struct {
 type Sandbox struct {
 	// ID of the sandbox
 	ID string
+	// Labels of the sandbox
+	Labels map[string]string
 }
 
 // Invoke the ConfList of nri plugins
@@ -75,6 +77,7 @@ func (c *Client) InvokeWithSandbox(ctx context.Context, task containerd.Task, st
 	}
 	if sandbox != nil {
 		r.SandboxID = sandbox.ID
+		r.Labels = sandbox.Labels
 	}
 	for _, p := range c.conf.Plugins {
 		r.Conf = p.Conf

vendor/github.com/containerd/nri/types/v1/types.go

@@ -75,6 +75,8 @@ type Request struct {
 	Pid int `json:"pid,omitempty"`
 	// Spec generated from the OCI runtime specification
 	Spec *Spec `json:"spec"`
+	// Labels of a sandbox
+	Labels map[string]string `json:"labels,omitempty"`
 	// Results from previous plugins in the chain
 	Results []*Result `json:"results,omitempty"`
 }