cri: support blockio class in pod and container annotations

This patch adds support for a container annotation and two separate
pod annotations for controlling the blockio class of containers.

The container annotation can be used by a CRI client:
  "io.kubernetes.cri.blockio-class"

Pod annotations specify the blockio class in the K8s pod spec level:
  "blockio.resources.beta.kubernetes.io/pod"
  (pod-wide default for all containers within)

  "blockio.resources.beta.kubernetes.io/container.<container_name>"
  (container-specific overrides)

Correspondingly, this patch adds support for --blockio-class and
--blockio-config-file to ctr, too.

This implementation follows the resource class annotation pattern
introduced in RDT and merged in commit 893701220.

Signed-off-by: Antti Kervinen <antti.kervinen@intel.com>

services/tasks/local.go

@@ -66,6 +66,8 @@ const (
 
 // Config for the tasks service plugin
 type Config struct {
+	// BlockIOConfigFile specifies the path to blockio configuration file
+	BlockIOConfigFile string `toml:"blockio_config_file" json:"blockioConfigFile"`
 	// RdtConfigFile specifies the path to RDT configuration file
 	RdtConfigFile string `toml:"rdt_config_file" json:"rdtConfigFile"`
 }
@@ -138,6 +140,9 @@ func initFunc(ic *plugin.InitContext) (interface{}, error) {
 		l.monitor.Monitor(t, nil)
 	}
 
+	if err := initBlockIO(config.BlockIOConfigFile); err != nil {
+		log.G(ic.Context).WithError(err).Errorf("blockio initialization failed")
+	}
 	if err := initRdt(config.RdtConfigFile); err != nil {
 		log.G(ic.Context).WithError(err).Errorf("RDT initialization failed")
 	}