Annotations: Provide container metadata for VM based runtimes

For hypervisor-based container runtimes (like Kata Containers, Clear Containers
or runv) a pod will be created in a VM and then create containers within the VM.

When a runtime is requested for container commands like create and start, both
the instal "pause" container and next containers need to be added to the pod
namespace (same VM).

A runtime does not know if it needs to create/start a VM or if it needs to add a
container to an already running VM pod.

This patch adds a way to provide this information through container annotations.
When starting a container or a sandbox, 2 annotations are added:

- type (Container or Sandbox)
- sandbox name

This allow to a VM based runtime to decide if they need to create a pod VM or
container within the VM pod.

Signed-off-by: Jose Carlos Venegas Munoz <jose.carlos.venegas.munoz@intel.com>

pkg/server/sandbox_run_test.go

@@ -20,6 +20,7 @@ import (
 	"os"
 	"testing"
 
+	"github.com/containerd/cri-containerd/pkg/annotations"
 	"github.com/containerd/typeurl"
 	"github.com/cri-o/ocicni/pkg/ocicni"
 	imagespec "github.com/opencontainers/image-spec/specs-go/v1"
@@ -64,6 +65,13 @@ func getRunPodSandboxTestData() (*runtime.PodSandboxConfig, *imagespec.ImageConf
 		assert.Equal(t, "/workspace", spec.Process.Cwd)
 		assert.EqualValues(t, *spec.Linux.Resources.CPU.Shares, defaultSandboxCPUshares)
 		assert.EqualValues(t, *spec.Process.OOMScoreAdj, defaultSandboxOOMAdj)
+
+		t.Logf("Check PodSandbox annotations")
+		assert.Contains(t, spec.Annotations, annotations.SandboxID)
+		assert.EqualValues(t, spec.Annotations[annotations.SandboxID], id)
+
+		assert.Contains(t, spec.Annotations, annotations.ContainerType)
+		assert.EqualValues(t, spec.Annotations[annotations.ContainerType], annotations.ContainerTypeSandbox)
 	}
 	return config, imageConfig, specCheck
 }