fix: app names with non-alphanumeric characters in position 63 break syncs (issue #18237)

util/argo/resource_tracking.go

@@ -2,6 +2,7 @@ package argo
 
 import (
 	"fmt"
+	"regexp"
 	"strings"
 
 	"k8s.io/apimachinery/pkg/apis/meta/v1/unstructured"
@@ -155,6 +156,13 @@ func (rt *resourceTracking) SetAppInstance(un *unstructured.Unstructured, key, v
 		}
 		if len(val) > LabelMaxLength {
 			val = val[:LabelMaxLength]
+			// Prevent errors if the truncated name ends in a special character.
+			// See https://github.com/argoproj/argo-cd/issues/18237.
+			okEndPattern := regexp.MustCompile("[a-zA-Z0-9]$")
+
+			for !okEndPattern.MatchString(val) {
+				val = val[:len(val)-1]
+			}
 		}
 		err = argokube.SetAppInstanceLabel(un, key, val)
 		if err != nil {

util/argo/resource_tracking_test.go

@@ -62,6 +62,46 @@ func TestSetAppInstanceAnnotationAndLabel(t *testing.T) {
 	assert.Equal(t, "my-app", app)
 }
 
+func TestSetAppInstanceAnnotationAndLabelLongName(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)
+
+	resourceTracking := NewResourceTracking()
+
+	err = resourceTracking.SetAppInstance(&obj, common.LabelKeyAppInstance, "my-app-with-an-extremely-long-name-that-is-over-sixty-three-characters", "", TrackingMethodAnnotationAndLabel)
+	assert.Nil(t, err)
+
+	// the annotation should still work, so the name from GetAppName should not be truncated
+	app := resourceTracking.GetAppName(&obj, common.LabelKeyAppInstance, TrackingMethodAnnotationAndLabel)
+	assert.Equal(t, "my-app-with-an-extremely-long-name-that-is-over-sixty-three-characters", app)
+
+	// the label should be truncated to 63 characters
+	assert.Equal(t, obj.GetLabels()[common.LabelKeyAppInstance], "my-app-with-an-extremely-long-name-that-is-over-sixty-three-cha")
+}
+
+func TestSetAppInstanceAnnotationAndLabelLongNameBadEnding(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)
+
+	resourceTracking := NewResourceTracking()
+
+	err = resourceTracking.SetAppInstance(&obj, common.LabelKeyAppInstance, "the-very-suspicious-name-with-precisely-sixty-three-characters-with-hyphen", "", TrackingMethodAnnotationAndLabel)
+	assert.Nil(t, err)
+
+	// the annotation should still work, so the name from GetAppName should not be truncated
+	app := resourceTracking.GetAppName(&obj, common.LabelKeyAppInstance, TrackingMethodAnnotationAndLabel)
+	assert.Equal(t, "the-very-suspicious-name-with-precisely-sixty-three-characters-with-hyphen", app)
+
+	// the label should be truncated to 63 characters, AND the hyphen should be removed
+	assert.Equal(t, obj.GetLabels()[common.LabelKeyAppInstance], "the-very-suspicious-name-with-precisely-sixty-three-characters")
+}
+
 func TestSetAppInstanceAnnotationNotFound(t *testing.T) {
 	yamlBytes, err := os.ReadFile("testdata/svc.yaml")
 	assert.Nil(t, err)