Support evented pleg feature in the Openshift

1. Incase of Evented PLEG, CRI-O sends the container events to the Kubelet so that the pod cache can be updated based on the received events.
KEP Reference: https://github.com/kubernetes/enhancements/blob/master/keps/sig-node/3386-kubelet-evented-pleg/README.md
2. This feature can be enabled in OCP by adding a new field in the node config custom resource
that can be monitored by the MCO and update both the required Kubelet and CRI-O configurations
Enhancement PR: openshift/enhancements#1368

Signed-off-by: Sai Ramesh Vanka <svanka@redhat.com>

config/v1/0000_10_config-operator_01_node.crd.yaml → config/v1/0000_10_config-operator_01_node-Default.crd.yaml

@@ -6,6 +6,7 @@ metadata:
     include.release.openshift.io/ibm-cloud-managed: "true"
     include.release.openshift.io/self-managed-high-availability: "true"
     include.release.openshift.io/single-node-developer: "true"
+    release.openshift.io/feature-set: Default
   name: nodes.config.openshift.io
 spec:
   group: config.openshift.io

config/v1/0000_10_config-operator_01_node-TechPreviewNoUpgrade.crd.yaml

@@ -0,0 +1,67 @@
+apiVersion: apiextensions.k8s.io/v1
+kind: CustomResourceDefinition
+metadata:
+  annotations:
+    api-approved.openshift.io: https://github.com/openshift/api/pull/1107
+    include.release.openshift.io/ibm-cloud-managed: "true"
+    include.release.openshift.io/self-managed-high-availability: "true"
+    include.release.openshift.io/single-node-developer: "true"
+    release.openshift.io/feature-set: TechPreviewNoUpgrade
+  name: nodes.config.openshift.io
+spec:
+  group: config.openshift.io
+  names:
+    kind: Node
+    listKind: NodeList
+    plural: nodes
+    singular: node
+  scope: Cluster
+  versions:
+    - name: v1
+      schema:
+        openAPIV3Schema:
+          description: "Node holds cluster-wide information about node specific features. \n Compatibility level 1: Stable within a major release for a minimum of 12 months or 3 minor releases (whichever is longer)."
+          type: object
+          required:
+            - spec
+          properties:
+            apiVersion:
+              description: 'APIVersion defines the versioned schema of this representation of an object. Servers should convert recognized schemas to the latest internal value, and may reject unrecognized values. More info: https://git.k8s.io/community/contributors/devel/sig-architecture/api-conventions.md#resources'
+              type: string
+            kind:
+              description: 'Kind is a string value representing the REST resource this object represents. Servers may infer this from the endpoint the client submits requests to. Cannot be updated. In CamelCase. More info: https://git.k8s.io/community/contributors/devel/sig-architecture/api-conventions.md#types-kinds'
+              type: string
+            metadata:
+              type: object
+            spec:
+              description: spec holds user settable values for configuration
+              type: object
+              properties:
+                cgroupMode:
+                  description: CgroupMode determines the cgroups version on the node
+                  type: string
+                  enum:
+                    - v1
+                    - v2
+                    - ""
+                eventedPleg:
+                  description: EventedPleg enables event based PLEG between the kubelet and the CRI-O
+                  type: string
+                  enum:
+                    - Enabled
+                    - Disabled
+                    - ""
+                workerLatencyProfile:
+                  description: WorkerLatencyProfile determins the how fast the kubelet is updating the status and corresponding reaction of the cluster
+                  type: string
+                  enum:
+                    - Default
+                    - MediumUpdateAverageReaction
+                    - LowUpdateSlowReaction
+            status:
+              description: status holds observed values.
+              type: object
+      served: true
+      storage: true
+      subresources:
+        status: {}

config/v1/types_node.go

@@ -42,6 +42,11 @@ type NodeSpec struct {
 	// the status and corresponding reaction of the cluster
 	// +optional
 	WorkerLatencyProfile WorkerLatencyProfileType `json:"workerLatencyProfile,omitempty"`
+
+	// EventedPleg enables event based PLEG between the kubelet and the CRI-O
+	// +openshift:enable:FeatureSets=TechPreviewNoUpgrade
+	// +optional
+	EventedPleg EventedPLEG `json:"eventedPleg,omitempty"`
 }
 
 type NodeStatus struct{}
@@ -70,6 +75,17 @@ const (
 	DefaultUpdateDefaultReaction WorkerLatencyProfileType = "Default"
 )
 
+// +kubebuilder:validation:Enum=Enabled;Disabled;""
+type EventedPLEG string
+
+const (
+	// Enabled enables the event based pleg between the kubelet and the cri-o
+	Enabled EventedPLEG = "Enabled"
+
+	// Disabled disables the event based pleg between the kubelet and the cri-o
+	Disabled EventedPLEG = "Disabled"
+)
+
 const (
 	// DefaultNodeStatusUpdateFrequency refers to the "--node-status-update-frequency" of the kubelet in case of DefaultUpdateDefaultReaction WorkerLatencyProfile type
 	DefaultNodeStatusUpdateFrequency = 10 * time.Second

openapi/openapi.json

@@ -7849,6 +7849,10 @@
           "description": "CgroupMode determines the cgroups version on the node",
           "type": "string"
         },
+        "eventedPleg": {
+          "description": "EventedPleg enables event based PLEG between the kubelet and the CRI-O",
+          "type": "string"
+        },
         "workerLatencyProfile": {
           "description": "WorkerLatencyProfile determins the how fast the kubelet is updating the status and corresponding reaction of the cluster",
           "type": "string"