improve error messages and logging

api/jobset/v1alpha2/jobset_webhook.go

@@ -37,6 +37,24 @@ import (
 	corev1 "k8s.io/api/core/v1"
 )
 
+const (
+	// This is the error message returned by IsDNS1035Label when the given input
+	// is longer than 63 characters.
+	dns1035MaxLengthExceededErrorMsg = "must be no more than 63 characters"
+
+	// Error message returned by JobSet validation if the generated child jobs
+	// will be longer than 63 characters.
+	jobNameTooLongErrorMsg = "JobSet name is too long, job names generated for this JobSet will exceed 63 characters"
+
+	// Error message returned by JobSet validation if the generated pod names
+	// will be longer than 63 characters.
+	podNameTooLongErrorMsg = "JobSet name is too long, job names generated for this JobSet will exceed 63 characters"
+
+	// Error message returned by JobSet validation if the network subdomain
+	// will be longer than 63 characters.
+	subdomainTooLongErrMsg = ".spec.network.subdomain is too long, must be less than 63 characters"
+)
+
 func (js *JobSet) SetupWebhookWithManager(mgr ctrl.Manager) error {
 	return ctrl.NewWebhookManagedBy(mgr).
 		For(js).
@@ -96,6 +114,9 @@ func (js *JobSet) ValidateCreate() (admission.Warnings, error) {
 
 		// Since subdomain name is also used as service name, it must adhere to RFC 1035 as well.
 		for _, errMessage := range validation.IsDNS1035Label(js.Spec.Network.Subdomain) {
+			if strings.Contains(errMessage, dns1035MaxLengthExceededErrorMsg) {
+				errMessage = subdomainTooLongErrMsg
+			}
 			allErrs = append(allErrs, fmt.Errorf(errMessage))
 		}
 	}
@@ -112,6 +133,9 @@ func (js *JobSet) ValidateCreate() (admission.Warnings, error) {
 		// Use the largest job index as it will have the longest name.
 		longestJobName := placement.GenJobName(js.Name, rjob.Name, int(rjob.Replicas-1))
 		for _, errMessage := range validation.IsDNS1035Label(longestJobName) {
+			if strings.Contains(errMessage, dns1035MaxLengthExceededErrorMsg) {
+				errMessage = jobNameTooLongErrorMsg
+			}
 			allErrs = append(allErrs, fmt.Errorf(errMessage))
 		}
 		// Check that the generated pod names for the replicated job is DNS 1035 compliant.
@@ -122,8 +146,8 @@ func (js *JobSet) ValidateCreate() (admission.Warnings, error) {
 			// Add 5 char suffix to the deterministic part of the pod name to validate the full pod name is compliant.
 			longestPodName := placement.GenPodName(js.Name, rjob.Name, maxJobIndex, maxPodIndex) + "-abcde"
 			for _, errMessage := range validation.IsDNS1035Label(longestPodName) {
-				if strings.Contains(errMessage, "must be no more than 63 characters") {
-					errMessage = "JobSet name must be shorter; pod names generated for this JobSet will exceed 63 characters."
+				if strings.Contains(errMessage, dns1035MaxLengthExceededErrorMsg) {
+					errMessage = podNameTooLongErrorMsg
 				}
 				allErrs = append(allErrs, fmt.Errorf(errMessage))
 			}

api/jobset/v1alpha2/jobset_webhook_test.go

@@ -532,7 +532,7 @@ func TestValidateCreate(t *testing.T) {
 				},
 			},
 			want: errors.Join(
-				fmt.Errorf("must be no more than 63 characters"),
+				fmt.Errorf(subdomainTooLongErrMsg),
 			),
 		},
 		{
@@ -576,7 +576,7 @@ func TestValidateCreate(t *testing.T) {
 				},
 			},
 			want: errors.Join(
-				fmt.Errorf("must be no more than 63 characters"),
+				fmt.Errorf(jobNameTooLongErrorMsg),
 			),
 		},
 		{
@@ -603,7 +603,7 @@ func TestValidateCreate(t *testing.T) {
 				},
 			},
 			want: errors.Join(
-				fmt.Errorf("JobSet name must be shorter; pod names generated for this JobSet will exceed 63 characters."),
+				fmt.Errorf(podNameTooLongErrorMsg),
 			),
 		},
 	}

pkg/webhooks/pod_admission_webhook.go

@@ -87,7 +87,7 @@ func (p *podWebhook) leaderPodForFollower(ctx context.Context, pod *corev1.Pod)
 	log := ctrl.LoggerFrom(ctx)
 	leaderPodName, err := genLeaderPodName(pod)
 	if err != nil {
-		log.Error(err, "getting leader pod name for follower pod")
+		log.V(3).Info("leader pod (%s) for follower pod does not exist or has not been scheduled yet", leaderPodName)
 		return nil, err
 	}