nrt: generalize topology manager config options

The NodeResourceTopology API is deprecating the `TopologyPolicies`
field, which was already a debatable way to express the Topology Manager
configuration.
Future version of the API will add top-level attributes, which can
encode the required TopologyManager configuration in key-value format.

An alternative legal way (which some implementations may also prefer)
is to provide an additional special-purpose Zone whose Type is
"TopologyManager". The scheduler will ignore all the data but the
Attributes.

Signed-off-by: Francesco Romani <[email protected]>

Author: ffromani

pkg/noderesourcetopology/config.go

@@ -0,0 +1,116 @@
+/*
+Copyright 2023 The Kubernetes Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package noderesourcetopology
+
+import (
+	"k8s.io/klog/v2"
+	kubeletconfig "k8s.io/kubernetes/pkg/kubelet/apis/config"
+
+	topologyv1alpha2 "github.com/k8stopologyawareschedwg/noderesourcetopology-api/pkg/apis/topology/v1alpha2"
+)
+
+const (
+	AttributeScope  = "topologyManagerScope"
+	AttributePolicy = "topologyManagerPolicy"
+)
+
+// TODO: handle topologyManagerPolicyOptions added in k8s 1.26
+
+func IsValidScope(scope string) bool {
+	if scope == kubeletconfig.ContainerTopologyManagerScope || scope == kubeletconfig.PodTopologyManagerScope {
+		return true
+	}
+	return false
+}
+
+func IsValidPolicy(policy string) bool {
+	if policy == kubeletconfig.NoneTopologyManagerPolicy || policy == kubeletconfig.BestEffortTopologyManagerPolicy ||
+		policy == kubeletconfig.RestrictedTopologyManagerPolicy || policy == kubeletconfig.SingleNumaNodeTopologyManagerPolicy {
+		return true
+	}
+	return false
+}
+
+type TopologyManagerConfig struct {
+	Scope  string
+	Policy string
+}
+
+func makeTopologyManagerConfigDefaults() TopologyManagerConfig {
+	return TopologyManagerConfig{
+		Scope:  kubeletconfig.ContainerTopologyManagerScope,
+		Policy: kubeletconfig.NoneTopologyManagerPolicy,
+	}
+}
+
+func topologyManagerConfigFromNodeResourceTopology(nodeTopology *topologyv1alpha2.NodeResourceTopology) TopologyManagerConfig {
+	conf := makeTopologyManagerConfigDefaults()
+	// Backward compatibility (v1alpha2 and previous). Deprecated, will be removed when the NRT API moves to v1beta1.
+	updateTopologyManagerConfigFromTopologyPolicies(&conf, nodeTopology.Name, nodeTopology.TopologyPolicies)
+	// preferred new configuration source (v1alpha2 and onwards)
+	updateTopologyManagerConfigFromAttributes(&conf, nodeTopology.Attributes)
+	return conf
+}
+
+func updateTopologyManagerConfigFromAttributes(conf *TopologyManagerConfig, attrs topologyv1alpha2.AttributeList) {
+	for _, attr := range attrs {
+		if attr.Name == AttributeScope && IsValidScope(attr.Value) {
+			conf.Scope = attr.Value
+			continue
+		}
+		if attr.Name == AttributePolicy && IsValidPolicy(attr.Value) {
+			conf.Policy = attr.Value
+			continue
+		}
+		// TODO: handle topologyManagerPolicyOptions added in k8s 1.26
+	}
+}
+
+func updateTopologyManagerConfigFromTopologyPolicies(conf *TopologyManagerConfig, nodeName string, topologyPolicies []string) {
+	if len(topologyPolicies) == 0 {
+		klog.V(3).InfoS("Cannot determine policy", "node", nodeName)
+		return
+	}
+	if len(topologyPolicies) > 1 {
+		klog.V(4).InfoS("Ignoring extra policies", "node", nodeName, "policies count", len(topologyPolicies)-1)
+	}
+
+	policyName := topologyv1alpha2.TopologyManagerPolicy(topologyPolicies[0])
+	klog.Warning("The `topologyPolicies` field is deprecated and will be removed with the NRT API v1beta1.")
+	klog.Warning("The `topologyPolicies` field is deprecated, please use top-level Attributes field instead.")
+
+	switch policyName {
+	case topologyv1alpha2.SingleNUMANodePodLevel:
+		conf.Policy = kubeletconfig.SingleNumaNodeTopologyManagerPolicy
+		conf.Scope = kubeletconfig.PodTopologyManagerScope
+	case topologyv1alpha2.SingleNUMANodeContainerLevel:
+		conf.Policy = kubeletconfig.SingleNumaNodeTopologyManagerPolicy
+		conf.Scope = kubeletconfig.ContainerTopologyManagerScope
+	case topologyv1alpha2.BestEffortPodLevel:
+		conf.Policy = kubeletconfig.BestEffortTopologyManagerPolicy
+		conf.Scope = kubeletconfig.PodTopologyManagerScope
+	case topologyv1alpha2.BestEffortContainerLevel:
+		conf.Policy = kubeletconfig.BestEffortTopologyManagerPolicy
+		conf.Scope = kubeletconfig.ContainerTopologyManagerScope
+	case topologyv1alpha2.RestrictedPodLevel:
+		conf.Policy = kubeletconfig.RestrictedTopologyManagerPolicy
+		conf.Scope = kubeletconfig.PodTopologyManagerScope
+	case topologyv1alpha2.RestrictedContainerLevel:
+		conf.Policy = kubeletconfig.RestrictedTopologyManagerPolicy
+		conf.Scope = kubeletconfig.ContainerTopologyManagerScope
+	}
+}