feat: add label intersection mode for precise pod targeting

pkg/types/types.go

@@ -9,6 +9,7 @@ import (
 	"time"
 
 	"github.com/litmuschaos/litmus-go/pkg/cerrors"
+	"github.com/litmuschaos/litmus-go/pkg/log"
 	"github.com/litmuschaos/litmus-go/pkg/utils/stringutils"
 
 	"github.com/litmuschaos/chaos-operator/api/litmuschaos/v1alpha1"
@@ -156,10 +157,11 @@ type ProbeContext struct {
 
 // AppDetails contains all the application related envs
 type AppDetails struct {
-	Namespace string
-	Labels    []string
-	Kind      string
-	Names     []string
+	Namespace      string
+	Labels         []string
+	Kind           string
+	Names          []string
+	LabelMatchMode string
 }
 
 func GetTargets(targets string) []AppDetails {
@@ -169,11 +171,27 @@ func GetTargets(targets string) []AppDetails {
 	}
 	t := strings.Split(targets, ";")
 	for _, k := range t {
-		val := strings.Split(strings.TrimSpace(k), ":")
+		trimmed := strings.TrimSpace(k)
+		if trimmed == "" {
+			continue
+		}
+		val := strings.Split(trimmed, ":")
+		if len(val) < 3 {
+			log.Fatalf("invalid TARGETS entry %q: expected format kind:namespace:[labels|names][:mode]", trimmed)
+		}
 		data := AppDetails{
-			Kind:      val[0],
-			Namespace: val[1],
+			Kind:           val[0],
+			Namespace:      val[1],
+			LabelMatchMode: "union",
 		}
+
+		if len(val) > 3 {
+			mode := strings.TrimSpace(val[3])
+			if mode == "intersection" || mode == "union" {
+				data.LabelMatchMode = mode
+			}
+		}
+
 		if strings.Contains(val[2], "=") {
 			data.Labels = parse(val[2])
 		} else {

pkg/types/types_test.go

@@ -0,0 +1,140 @@
+package types
+
+import (
+	"testing"
+)
+
+func TestGetTargets_UnionModeDefault(t *testing.T) {
+	// Test that union is the default mode when not specified
+	targets := "deployment:default:[app=nginx,tier=frontend]"
+	result := GetTargets(targets)
+
+	if len(result) != 1 {
+		t.Errorf("Expected 1 AppDetail, got %d", len(result))
+	}
+
+	if result[0].LabelMatchMode != "union" {
+		t.Errorf("Expected default LabelMatchMode to be 'union', got '%s'", result[0].LabelMatchMode)
+	}
+
+	if result[0].Kind != "deployment" {
+		t.Errorf("Expected Kind to be 'deployment', got '%s'", result[0].Kind)
+	}
+
+	if result[0].Namespace != "default" {
+		t.Errorf("Expected Namespace to be 'default', got '%s'", result[0].Namespace)
+	}
+
+	if len(result[0].Labels) != 2 {
+		t.Errorf("Expected 2 labels, got %d", len(result[0].Labels))
+	}
+}
+
+func TestGetTargets_ExplicitUnionMode(t *testing.T) {
+	// Test explicit union mode
+	targets := "statefulset:prod:[app=postgres,role=primary]:union"
+	result := GetTargets(targets)
+
+	if len(result) != 1 {
+		t.Errorf("Expected 1 AppDetail, got %d", len(result))
+	}
+
+	if result[0].LabelMatchMode != "union" {
+		t.Errorf("Expected LabelMatchMode to be 'union', got '%s'", result[0].LabelMatchMode)
+	}
+
+	if result[0].Kind != "statefulset" {
+		t.Errorf("Expected Kind to be 'statefulset', got '%s'", result[0].Kind)
+	}
+}
+
+func TestGetTargets_IntersectionMode(t *testing.T) {
+	// Test intersection mode
+	targets := "cluster:default:[cnpg.io/instanceRole=primary,cnpg.io/cluster=pg-eu]:intersection"
+	result := GetTargets(targets)
+
+	if len(result) != 1 {
+		t.Errorf("Expected 1 AppDetail, got %d", len(result))
+	}
+
+	if result[0].LabelMatchMode != "intersection" {
+		t.Errorf("Expected LabelMatchMode to be 'intersection', got '%s'", result[0].LabelMatchMode)
+	}
+
+	if result[0].Kind != "cluster" {
+		t.Errorf("Expected Kind to be 'cluster', got '%s'", result[0].Kind)
+	}
+
+	if result[0].Namespace != "default" {
+		t.Errorf("Expected Namespace to be 'default', got '%s'", result[0].Namespace)
+	}
+
+	if len(result[0].Labels) != 2 {
+		t.Errorf("Expected 2 labels, got %d", len(result[0].Labels))
+	}
+
+	expectedLabels := []string{"cnpg.io/instanceRole=primary", "cnpg.io/cluster=pg-eu"}
+	for i, label := range result[0].Labels {
+		if label != expectedLabels[i] {
+			t.Errorf("Expected label[%d] to be '%s', got '%s'", i, expectedLabels[i], label)
+		}
+	}
+}
+
+func TestGetTargets_InvalidMode(t *testing.T) {
+	// Test that invalid mode falls back to union
+	targets := "deployment:default:[app=nginx]:invalid"
+	result := GetTargets(targets)
+
+	if len(result) != 1 {
+		t.Errorf("Expected 1 AppDetail, got %d", len(result))
+	}
+
+	// Invalid mode should fall back to union
+	if result[0].LabelMatchMode != "union" {
+		t.Errorf("Expected invalid mode to fall back to 'union', got '%s'", result[0].LabelMatchMode)
+	}
+}
+
+func TestGetTargets_MultipleSemicolonSeparated(t *testing.T) {
+	// Test multiple targets with different modes
+	targets := "deployment:ns1:[app=web]:union;statefulset:ns2:[db=postgres,env=prod]:intersection"
+	result := GetTargets(targets)
+
+	if len(result) != 2 {
+		t.Errorf("Expected 2 AppDetails, got %d", len(result))
+	}
+
+	// First target - union
+	if result[0].LabelMatchMode != "union" {
+		t.Errorf("Expected first target LabelMatchMode to be 'union', got '%s'", result[0].LabelMatchMode)
+	}
+
+	// Second target - intersection
+	if result[1].LabelMatchMode != "intersection" {
+		t.Errorf("Expected second target LabelMatchMode to be 'intersection', got '%s'", result[1].LabelMatchMode)
+	}
+}
+
+func TestGetTargets_WithNames(t *testing.T) {
+	// Test that Names parsing still works with the new field
+	targets := "pod:default:[pod1,pod2,pod3]"
+	result := GetTargets(targets)
+
+	if len(result) != 1 {
+		t.Errorf("Expected 1 AppDetail, got %d", len(result))
+	}
+
+	if len(result[0].Names) != 3 {
+		t.Errorf("Expected 3 names, got %d", len(result[0].Names))
+	}
+
+	if len(result[0].Labels) != 0 {
+		t.Errorf("Expected 0 labels when Names are provided, got %d", len(result[0].Labels))
+	}
+
+	// Default mode should still be union
+	if result[0].LabelMatchMode != "union" {
+		t.Errorf("Expected default LabelMatchMode to be 'union', got '%s'", result[0].LabelMatchMode)
+	}
+}

pkg/utils/common/pods.go

@@ -306,16 +306,30 @@ func GetTargetPodsWhenTargetPodsENVNotSet(podAffPerc int, clients clients.Client
 				}
 				finalPods.Items = append(finalPods.Items, pods.Items...)
 			} else {
-				for _, label := range target.Labels {
-					pods, err := clients.KubeClient.CoreV1().Pods(target.Namespace).List(context.Background(), v1.ListOptions{LabelSelector: label})
+				// Check label match mode to determine union vs intersection
+				if target.LabelMatchMode == "intersection" {
+					// INTERSECTION: Get pods matching ALL labels
+					pods, err := getPodsWithIntersectionLabels(target, clients)
 					if err != nil {
-						return finalPods, cerrors.Error{ErrorCode: cerrors.ErrorTypeTargetSelection, Target: fmt.Sprintf("{podLabel: %s, namespace: %s}", label, target.Namespace), Reason: err.Error()}
+						return finalPods, err
 					}
-					filteredPods, err := filterPodsByOwnerKind(pods.Items, target, clients)
+					filteredPods, err := filterPodsByOwnerKind(pods, target, clients)
 					if err != nil {
 						return finalPods, stacktrace.Propagate(err, "could not identify parent type from pod")
 					}
 					finalPods.Items = append(finalPods.Items, filteredPods...)
+				} else {
+					for _, label := range target.Labels {
+						pods, err := clients.KubeClient.CoreV1().Pods(target.Namespace).List(context.Background(), v1.ListOptions{LabelSelector: label})
+						if err != nil {
+							return finalPods, cerrors.Error{ErrorCode: cerrors.ErrorTypeTargetSelection, Target: fmt.Sprintf("{podLabel: %s, namespace: %s}", label, target.Namespace), Reason: err.Error()}
+						}
+						filteredPods, err := filterPodsByOwnerKind(pods.Items, target, clients)
+						if err != nil {
+							return finalPods, stacktrace.Propagate(err, "could not identify parent type from pod")
+						}
+						finalPods.Items = append(finalPods.Items, filteredPods...)
+					}
 				}
 			}
 		}
@@ -331,6 +345,42 @@ func GetTargetPodsWhenTargetPodsENVNotSet(podAffPerc int, clients clients.Client
 	return filterPodsByPercentage(finalPods, podAffPerc), nil
 }
 
+// getPodsWithIntersectionLabels returns pods that match ALL the provided labels (intersection)
+func getPodsWithIntersectionLabels(target types.AppDetails, clients clients.ClientSets) ([]core_v1.Pod, error) {
+	if len(target.Labels) == 0 {
+		return nil, cerrors.Error{
+			ErrorCode: cerrors.ErrorTypeTargetSelection,
+			Target:    fmt.Sprintf("{namespace: %s, kind: %s}", target.Namespace, target.Kind),
+			Reason:    "no labels provided for intersection",
+		}
+	}
+
+	// Build comma-separated label selector for intersection (AND logic)
+	// e.g., "app=nginx,env=prod,role=primary"
+	labelSelector := strings.Join(target.Labels, ",")
+
+	pods, err := clients.KubeClient.CoreV1().Pods(target.Namespace).List(context.Background(), v1.ListOptions{
+		LabelSelector: labelSelector,
+	})
+	if err != nil {
+		return nil, cerrors.Error{
+			ErrorCode: cerrors.ErrorTypeTargetSelection,
+			Target:    fmt.Sprintf("{labels: %v, namespace: %s}", target.Labels, target.Namespace),
+			Reason:    err.Error(),
+		}
+	}
+
+	if len(pods.Items) == 0 {
+		return nil, cerrors.Error{
+			ErrorCode: cerrors.ErrorTypeTargetSelection,
+			Target:    fmt.Sprintf("{labels: %v, namespace: %s}", target.Labels, target.Namespace),
+			Reason:    "no pods found matching all labels",
+		}
+	}
+
+	return pods.Items, nil
+}
+
 func filterPodsByOwnerKind(pods []core_v1.Pod, target types.AppDetails, clients clients.ClientSets) ([]core_v1.Pod, error) {
 	var filteredPods []core_v1.Pod
 	for _, pod := range pods {