Fix label truncation possibly ending with invalid character argoproj#…

…10110

util/argo/resource_tracking.go

@@ -2,6 +2,7 @@ package argo
 
 import (
 	"fmt"
+	"regexp"
 	"strings"
 
 	"k8s.io/apimachinery/pkg/apis/meta/v1/unstructured"
@@ -21,6 +22,7 @@ const (
 
 var WrongResourceTrackingFormat = fmt.Errorf("wrong resource tracking format, should be <application-name>:<group>/<kind>:<namespace>/<name>")
 var LabelMaxLength = 63
+var nonAlphanumericSuffixRegex = regexp.MustCompile("[^a-zA-Z0-9]+$")
 
 // ResourceTracking defines methods which allow setup and retrieve tracking information to resource
 type ResourceTracking interface {
@@ -153,9 +155,7 @@ func (rt *resourceTracking) SetAppInstance(un *unstructured.Unstructured, key, v
 		if err != nil {
 			return err
 		}
-		if len(val) > LabelMaxLength {
-			val = val[:LabelMaxLength]
-		}
+		val = truncateLabelValue(val)
 		err = argokube.SetAppInstanceLabel(un, key, val)
 		if err != nil {
 			return fmt.Errorf("failed to set app instance label: %w", err)
@@ -239,3 +239,16 @@ func (rt *resourceTracking) Normalize(config, live *unstructured.Unstructured, l
 
 	return nil
 }
+
+// truncateLabelValue truncates input label value string to a valid Kubernetes label value
+// Which is limited to 63 characters and must end with alphanumeric characters
+// https://kubernetes.io/docs/concepts/overview/working-with-objects/labels/#syntax-and-character-set
+func truncateLabelValue(str string) string {
+	if len(str) > LabelMaxLength {
+		str = str[:LabelMaxLength]
+	}
+
+	// Remove non-alphanumeric characters at the end of the string
+	str = nonAlphanumericSuffixRegex.ReplaceAllString(str, "")
+	return str
+}

util/argo/resource_tracking_test.go

@@ -47,19 +47,31 @@ func TestSetAppInstanceAnnotation(t *testing.T) {
 }
 
 func TestSetAppInstanceAnnotationAndLabel(t *testing.T) {
-	yamlBytes, err := os.ReadFile("testdata/svc.yaml")
-	assert.Nil(t, err)
-	var obj unstructured.Unstructured
-	err = yaml.Unmarshal(yamlBytes, &obj)
-	assert.Nil(t, err)
+	testScenarios := map[string]string{
+		"my-app": "my-app",
+		"my-app-with-very-long-app-name-that-will-get-truncated-correctly-1234":         "my-app-with-very-long-app-name-that-will-get-truncated-correctl",
+		"my-app-with-veryvery-long-app-name-that-will-not-get-truncated-correctly-1234": "my-app-with-veryvery-long-app-name-that-will-not-get-truncated",
+		"my-app-with-a-bunch-of-hyphens-------------------------------------------1234": "my-app-with-a-bunch-of-hyphens",
+	}
 
-	resourceTracking := NewResourceTracking()
+	for inputAppName, expectedLabelValue := range testScenarios {
+		yamlBytes, err := os.ReadFile("testdata/svc.yaml")
+		assert.Nil(t, err)
 
-	err = resourceTracking.SetAppInstance(&obj, common.LabelKeyAppInstance, "my-app", "", TrackingMethodAnnotationAndLabel)
-	assert.Nil(t, err)
+		var obj unstructured.Unstructured
+		err = yaml.Unmarshal(yamlBytes, &obj)
+		assert.Nil(t, err)
 
-	app := resourceTracking.GetAppName(&obj, common.LabelKeyAppInstance, TrackingMethodAnnotationAndLabel)
-	assert.Equal(t, "my-app", app)
+		resourceTracking := NewResourceTracking()
+		err = resourceTracking.SetAppInstance(&obj, common.LabelKeyAppInstance, inputAppName, "", TrackingMethodAnnotationAndLabel)
+		assert.Nil(t, err)
+
+		actualAppName := resourceTracking.GetAppName(&obj, common.LabelKeyAppInstance, TrackingMethodAnnotationAndLabel)
+		assert.Equal(t, inputAppName, actualAppName)
+
+		actualLabelValue := obj.GetLabels()[common.LabelKeyAppInstance]
+		assert.Equal(t, expectedLabelValue, actualLabelValue)
+	}
 }
 
 func TestSetAppInstanceAnnotationNotFound(t *testing.T) {