From 96262a3784448ecd6922343017f88881f53db16c Mon Sep 17 00:00:00 2001
From: Markus Lehtonen <markus.lehtonen@intel.com>
Date: Mon, 3 Mar 2025 15:02:31 +0200
Subject: [PATCH] nodefeaturegroup: implement vars

Implement handling of Vars and VarsTemplate fields or NodeFeatureGroup.
---
 pkg/apis/nfd/nodefeaturerule/rule.go | 37 ++++++++++++++++++++++------
 pkg/nfd-master/nfd-master.go         | 17 +++++++------
 2 files changed, 39 insertions(+), 15 deletions(-)

diff --git a/pkg/apis/nfd/nodefeaturerule/rule.go b/pkg/apis/nfd/nodefeaturerule/rule.go
index 21e052b0e..a02647dfa 100644
--- a/pkg/apis/nfd/nodefeaturerule/rule.go
+++ b/pkg/apis/nfd/nodefeaturerule/rule.go
@@ -147,50 +147,71 @@ func Execute(r *nfdv1alpha1.Rule, features *nfdv1alpha1.Features, failFast bool)
 	return ret, nil
 }
 
+// GroupRuleOutput contains the output of group rule execution.
+type GroupRuleOutput struct {
+	Vars        map[string]string
+	MatchStatus *MatchStatus
+}
+
 // ExecuteGroupRule executes the GroupRule against a set of input features, and return true if the
 // rule matches.
-func ExecuteGroupRule(r *nfdv1alpha1.GroupRule, features *nfdv1alpha1.Features, failFast bool) (MatchStatus, error) {
+func ExecuteGroupRule(r *nfdv1alpha1.GroupRule, features *nfdv1alpha1.Features, failFast bool) (GroupRuleOutput, error) {
 	var (
 		matchStatus MatchStatus
 		isMatch     bool
 	)
+	vars := make(map[string]string)
+
 	if n := len(r.MatchAny); n > 0 {
 		matchStatus.MatchAny = make([]*MatchFeatureStatus, 0, n)
 		// Logical OR over the matchAny matchers
 		for _, matcher := range r.MatchAny {
 			matched, featureStatus, err := evaluateMatchAnyElem(&matcher, features, failFast)
 			if err != nil {
-				return matchStatus, err
+				return GroupRuleOutput{}, err
 			} else if matched {
 				isMatch = true
 				klog.V(4).InfoS("matchAny matched", "ruleName", r.Name, "matchedFeatures", utils.DelayedDumper(featureStatus.MatchedFeatures))
 
-				if failFast {
+				if r.VarsTemplate == "" && failFast {
 					// there's no need to evaluate other matchers in MatchAny
+					// if there are no templates to be executed on them
 					break
 				}
+
+				if err := executeTemplate(r.VarsTemplate, featureStatus.MatchedFeatures, vars); err != nil {
+					return GroupRuleOutput{}, err
+				}
 			}
 			matchStatus.MatchAny = append(matchStatus.MatchAny, featureStatus)
 		}
 		if !isMatch && failFast {
-			return matchStatus, nil
+			return GroupRuleOutput{MatchStatus: &matchStatus}, nil
 		}
 	}
 
 	if len(r.MatchFeatures) > 0 {
 		var err error
 		if isMatch, matchStatus.MatchFeatureStatus, err = evaluateFeatureMatcher(&r.MatchFeatures, features, failFast); err != nil {
-			return matchStatus, err
+			return GroupRuleOutput{}, err
 		} else if !isMatch {
 			klog.V(2).InfoS("rule did not match", "ruleName", r.Name)
-			return matchStatus, nil
+			return GroupRuleOutput{MatchStatus: &matchStatus}, nil
+		}
+		if err := executeTemplate(r.VarsTemplate, matchStatus.MatchedFeatures, vars); err != nil {
+			return GroupRuleOutput{}, err
 		}
 	}
 
+	maps.Copy(vars, r.Vars)
 	matchStatus.IsMatch = true
 
-	klog.V(2).InfoS("rule matched", "ruleName", r.Name)
-	return matchStatus, nil
+	ret := GroupRuleOutput{
+		Vars:        vars,
+		MatchStatus: &matchStatus,
+	}
+	klog.V(2).InfoS("rule matched", "ruleName", r.Name, "ruleOutput", utils.DelayedDumper(ret))
+	return ret, nil
 }
 
 func executeTemplate(tmpl string, in matchedFeatures, out map[string]string) error {
diff --git a/pkg/nfd-master/nfd-master.go b/pkg/nfd-master/nfd-master.go
index 51e02345d..fbe12e040 100644
--- a/pkg/nfd-master/nfd-master.go
+++ b/pkg/nfd-master/nfd-master.go
@@ -717,7 +717,7 @@ func (m *nfdMaster) nfdAPIUpdateNodeFeatureGroup(nfdClient nfdclientset.Interfac
 	if err != nil {
 		return fmt.Errorf("failed to get nodes: %w", err)
 	}
-	nodeFeaturesList := make([]*nfdv1alpha1.NodeFeature, 0)
+	nodeFeaturesList := make([]*nfdv1alpha1.Features, 0)
 	for _, node := range nodes.Items {
 		// Merge all NodeFeature objects into a single NodeFeatureSpec
 		nodeFeatures, err := m.getAndMergeNodeFeatures(node.Name)
@@ -728,22 +728,22 @@ func (m *nfdMaster) nfdAPIUpdateNodeFeatureGroup(nfdClient nfdclientset.Interfac
 			// Nothing to do for this node
 			continue
 		}
-		nodeFeaturesList = append(nodeFeaturesList, nodeFeatures)
+		nodeFeaturesList = append(nodeFeaturesList, &nodeFeatures.Spec.Features)
 	}
 
 	// Execute rules and create matching groups
 	nodePool := make([]nfdv1alpha1.FeatureGroupNode, 0)
 	nodeGroupValidator := make(map[string]bool)
-	for _, rule := range nodeFeatureGroup.Spec.Rules {
-		for _, feature := range nodeFeaturesList {
-			match, err := nodefeaturerule.ExecuteGroupRule(&rule, &feature.Spec.Features, true)
+	for _, features := range nodeFeaturesList {
+		for _, rule := range nodeFeatureGroup.Spec.Rules {
+			ruleOut, err := nodefeaturerule.ExecuteGroupRule(&rule, features, true)
 			if err != nil {
 				klog.ErrorS(err, "failed to evaluate rule", "ruleName", rule.Name)
 				continue
 			}
 
-			if match.IsMatch {
-				system := feature.Spec.Features.Attributes["system.name"]
+			if ruleOut.MatchStatus.IsMatch {
+				system := features.Attributes["system.name"]
 				nodeName := system.Elements["nodename"]
 				if _, ok := nodeGroupValidator[nodeName]; !ok {
 					nodePool = append(nodePool, nfdv1alpha1.FeatureGroupNode{
@@ -752,6 +752,9 @@ func (m *nfdMaster) nfdAPIUpdateNodeFeatureGroup(nfdClient nfdclientset.Interfac
 					nodeGroupValidator[nodeName] = true
 				}
 			}
+
+			// Feed back vars from rule output to features map for subsequent rules to match
+			features.InsertAttributeFeatures(nfdv1alpha1.RuleBackrefDomain, nfdv1alpha1.RuleBackrefFeature, ruleOut.Vars)
 		}
 	}