ok

apis/actions.github.com/v1alpha1/ephemeralrunnerset_types.go

@@ -52,6 +52,12 @@ type EphemeralRunnerSetStatus struct {
 	// Unset defaults to 0.
 	// +optional
 	AppliedActionableRevision int64 `json:"appliedActionableRevision,omitempty"`
+	// FinishedRunnerCleanupPatchID records the listener patch ID for which finished
+	// ephemeral runners were cleaned up. Scale-up is suppressed for the same patch ID
+	// until the listener publishes a fresh desired-state patch.
+	// Unset defaults to 0.
+	// +optional
+	FinishedRunnerCleanupPatchID int `json:"finishedRunnerCleanupPatchID,omitempty"`
 }
 
 // EphemeralRunnerSetPhase is the phase of the ephemeral runner set resource

charts/gha-runner-scale-set-controller-experimental/crds/actions.github.com_ephemeralrunnersets.yaml

@@ -8309,6 +8309,13 @@ spec:
                     Unset defaults to 0.
                   format: int64
                   type: integer
+                finishedRunnerCleanupPatchID:
+                  description: |-
+                    FinishedRunnerCleanupPatchID records the listener patch ID for which finished
+                    ephemeral runners were cleaned up. Scale-up is suppressed for the same patch ID
+                    until the listener publishes a fresh desired-state patch.
+                    Unset defaults to 0.
+                  type: integer
                 phase:
                   description: EphemeralRunnerSetPhase is the phase of the ephemeral runner set resource
                   type: string

charts/gha-runner-scale-set-controller/crds/actions.github.com_ephemeralrunnersets.yaml

@@ -8309,6 +8309,13 @@ spec:
                     Unset defaults to 0.
                   format: int64
                   type: integer
+                finishedRunnerCleanupPatchID:
+                  description: |-
+                    FinishedRunnerCleanupPatchID records the listener patch ID for which finished
+                    ephemeral runners were cleaned up. Scale-up is suppressed for the same patch ID
+                    until the listener publishes a fresh desired-state patch.
+                    Unset defaults to 0.
+                  type: integer
                 phase:
                   description: EphemeralRunnerSetPhase is the phase of the ephemeral runner set resource
                   type: string

config/crd/bases/actions.github.com_ephemeralrunnersets.yaml

@@ -8309,6 +8309,13 @@ spec:
                     Unset defaults to 0.
                   format: int64
                   type: integer
+                finishedRunnerCleanupPatchID:
+                  description: |-
+                    FinishedRunnerCleanupPatchID records the listener patch ID for which finished
+                    ephemeral runners were cleaned up. Scale-up is suppressed for the same patch ID
+                    until the listener publishes a fresh desired-state patch.
+                    Unset defaults to 0.
+                  type: integer
                 phase:
                   description: EphemeralRunnerSetPhase is the phase of the ephemeral runner set resource
                   type: string

controllers/actions.github.com/ephemeralrunnerset_controller.go

@@ -201,15 +201,31 @@ func (r *EphemeralRunnerSetReconciler) Reconcile(ctx context.Context, req ctrl.R
 
 	total := ephemeralRunnersByState.scaleTotal()
 	if ephemeralRunnerSet.Spec.PatchID == 0 || ephemeralRunnerSet.Spec.PatchID != ephemeralRunnersByState.latestPatchID {
-		defer func() {
+		if len(ephemeralRunnersByState.finished) > 0 {
 			if err := r.cleanupFinishedEphemeralRunners(ctx, ephemeralRunnersByState.finished, log); err != nil {
 				log.Error(err, "failed to cleanup finished ephemeral runners")
+				return ctrl.Result{}, err
 			}
-		}()
-		log.Info("Scaling comparison", "current", total, "desired", ephemeralRunnerSet.Spec.Replicas)
+			if err := r.patchFinishedRunnerCleanupPatchIDStatus(ctx, req.NamespacedName, ephemeralRunnerSet.Spec.PatchID); err != nil {
+				log.Error(err, "failed to update finished runner cleanup patch ID status")
+				return ctrl.Result{}, err
+			}
+			ephemeralRunnerSet.Status.FinishedRunnerCleanupPatchID = ephemeralRunnerSet.Spec.PatchID
+
+			log.Info("Finished ephemeral runners were cleaned up, deferring scaling decision")
+			return ctrl.Result{}, r.updateStatus(ctx, &ephemeralRunnerSet, ephemeralRunnersByState, log)
+		}
+
+		scaleUpTotal := total + len(ephemeralRunnersByState.deleting)
+		log.Info("Scaling comparison", "current", total, "deleting", len(ephemeralRunnersByState.deleting), "desired", ephemeralRunnerSet.Spec.Replicas)
 		switch {
-		case total < ephemeralRunnerSet.Spec.Replicas: // Handle scale up
-			count := ephemeralRunnerSet.Spec.Replicas - total
+		case scaleUpTotal < ephemeralRunnerSet.Spec.Replicas: // Handle scale up
+			if ephemeralRunnerSet.Spec.PatchID > 0 && ephemeralRunnerSet.Status.FinishedRunnerCleanupPatchID == ephemeralRunnerSet.Spec.PatchID {
+				log.Info("Skipping scale up until listener publishes a fresh desired state after finished runner cleanup", "patchID", ephemeralRunnerSet.Spec.PatchID)
+				return ctrl.Result{}, r.updateStatus(ctx, &ephemeralRunnerSet, ephemeralRunnersByState, log)
+			}
+
+			count := ephemeralRunnerSet.Spec.Replicas - scaleUpTotal
 			log.Info("Creating new ephemeral runners (scale up)", "count", count)
 			if err := r.createEphemeralRunners(ctx, &ephemeralRunnerSet, count, log); err != nil {
 				log.Error(err, "failed to make ephemeral runner")
@@ -268,6 +284,24 @@ func (r *EphemeralRunnerSetReconciler) patchAppliedActionableRevisionStatus(ctx
 	})
 }
 
+func (r *EphemeralRunnerSetReconciler) patchFinishedRunnerCleanupPatchIDStatus(ctx context.Context, key types.NamespacedName, patchID int) error {
+	return retry.RetryOnConflict(retry.DefaultBackoff, func() error {
+		var latest v1alpha1.EphemeralRunnerSet
+		if err := r.Get(ctx, key, &latest); err != nil {
+			return err
+		}
+
+		original := latest.DeepCopy()
+		latest.Status.FinishedRunnerCleanupPatchID = patchID
+
+		if original.Status == latest.Status {
+			return nil
+		}
+
+		return r.Status().Patch(ctx, &latest, client.MergeFrom(original))
+	})
+}
+
 func (r *EphemeralRunnerSetReconciler) updateStatus(ctx context.Context, ephemeralRunnerSet *v1alpha1.EphemeralRunnerSet, state *ephemeralRunnersByState, log logr.Logger) error {
 	original := ephemeralRunnerSet.DeepCopy()
 	var phase v1alpha1.EphemeralRunnerSetPhase
@@ -280,8 +314,9 @@ func (r *EphemeralRunnerSetReconciler) updateStatus(ctx context.Context, ephemer
 		phase = ephemeralRunnerSet.Status.Phase
 	}
 	desiredStatus := v1alpha1.EphemeralRunnerSetStatus{
-		Phase:                     phase,
-		AppliedActionableRevision: ephemeralRunnerSet.Status.AppliedActionableRevision,
+		Phase:                        phase,
+		AppliedActionableRevision:    ephemeralRunnerSet.Status.AppliedActionableRevision,
+		FinishedRunnerCleanupPatchID: ephemeralRunnerSet.Status.FinishedRunnerCleanupPatchID,
 	}
 
 	// Update the status if needed.

controllers/actions.github.com/ephemeralrunnerset_controller_test.go

@@ -627,7 +627,7 @@ var _ = Describe("Test EphemeralRunnerSet controller", func() {
 
 			// confirm they are not deleted
 			runnerList = new(v1alpha1.EphemeralRunnerList)
-			Consistently(
+			Eventually(
 				func() (int, error) {
 					err := listEphemeralRunnersAndRemoveFinalizers(ctx, k8sClient, runnerList, ephemeralRunnerSet.Namespace)
 					if err != nil {
@@ -690,7 +690,32 @@ var _ = Describe("Test EphemeralRunnerSet controller", func() {
 			Expect(err).NotTo(HaveOccurred(), "failed to update EphemeralRunnerSet")
 
 			runnerList = new(v1alpha1.EphemeralRunnerList)
-			// We should have 3 runners, and have no Succeeded ones
+			Eventually(
+				func() (int, error) {
+					err := listEphemeralRunnersAndRemoveFinalizers(ctx, k8sClient, runnerList, ephemeralRunnerSet.Namespace)
+					if err != nil {
+						return -1, err
+					}
+
+					return len(runnerList.Items), nil
+				},
+				ephemeralRunnerSetTestTimeout,
+				ephemeralRunnerSetTestInterval,
+			).Should(BeEquivalentTo(1), "only the running EphemeralRunner should remain before listener confirms the larger desired count")
+
+			ers = new(v1alpha1.EphemeralRunnerSet)
+			err = k8sClient.Get(ctx, client.ObjectKey{Name: ephemeralRunnerSet.Name, Namespace: ephemeralRunnerSet.Namespace}, ers)
+			Expect(err).NotTo(HaveOccurred(), "failed to get EphemeralRunnerSet")
+
+			updated = ers.DeepCopy()
+			updated.Spec.Replicas = 3
+			updated.Spec.PatchID = 3
+
+			err = k8sClient.Patch(ctx, updated, client.MergeFrom(ers))
+			Expect(err).NotTo(HaveOccurred(), "failed to update EphemeralRunnerSet")
+
+			runnerList = new(v1alpha1.EphemeralRunnerList)
+			// We should have 3 runners, and have no Succeeded ones after listener confirms.
 			Eventually(
 				func() error {
 					err := listEphemeralRunnersAndRemoveFinalizers(ctx, k8sClient, runnerList, ephemeralRunnerSet.Namespace)
@@ -698,16 +723,16 @@ var _ = Describe("Test EphemeralRunnerSet controller", func() {
 						return err
 					}
 
-					if len(runnerList.Items) != 3 {
-						return fmt.Errorf("Expected 3 runners, got %d", len(runnerList.Items))
-					}
-
 					for _, runner := range runnerList.Items {
 						if runner.Status.Phase == v1alpha1.EphemeralRunnerPhaseSucceeded {
 							return fmt.Errorf("Runner %s is in Succeeded phase", runner.Name)
 						}
 					}
 
+					if len(runnerList.Items) != 3 {
+						return fmt.Errorf("Expected 3 runners, got %d", len(runnerList.Items))
+					}
+
 					return nil
 				},
 				ephemeralRunnerSetTestTimeout,
@@ -1017,7 +1042,7 @@ var _ = Describe("Test EphemeralRunnerSet controller", func() {
 						}
 					}
 
-					if succeeded != 1 && running != 1 {
+					if succeeded != 1 || running != 1 {
 						return fmt.Errorf("Expected 1 runner in Succeeded and 1 in Running, got %d in Succeeded and %d in Running", succeeded, running)
 					}
 
@@ -1027,8 +1052,9 @@ var _ = Describe("Test EphemeralRunnerSet controller", func() {
 				ephemeralRunnerSetTestInterval,
 			).Should(BeNil(), "1 EphemeralRunner should be in Succeeded and 1 in Running phase")
 
-			// Now, let's simulate replacement. The desired count is still 2.
-			// This simulates that we got 1 job assigned, and 1 job completed.
+			// Now, let's simulate the listener publishing a stale patch before it has
+			// accounted for the completed job. The controller should clean up the
+			// finished runner but not create a replacement for this patch.
 
 			ers = new(v1alpha1.EphemeralRunnerSet)
 			err = k8sClient.Get(ctx, client.ObjectKey{Name: ephemeralRunnerSet.Name, Namespace: ephemeralRunnerSet.Namespace}, ers)
@@ -1041,6 +1067,33 @@ var _ = Describe("Test EphemeralRunnerSet controller", func() {
 			err = k8sClient.Patch(ctx, updated, client.MergeFrom(ers))
 			Expect(err).NotTo(HaveOccurred(), "failed to update EphemeralRunnerSet")
 
+			runnerList = new(v1alpha1.EphemeralRunnerList)
+			Consistently(
+				func() (int, error) {
+					err := listEphemeralRunnersAndRemoveFinalizers(ctx, k8sClient, runnerList, ephemeralRunnerSet.Namespace)
+					if err != nil {
+						return -1, err
+					}
+
+					return len(runnerList.Items), nil
+				},
+				2*time.Second,
+				ephemeralRunnerSetTestInterval,
+			).Should(BeEquivalentTo(1), "only the running EphemeralRunner should remain before listener confirms replacement")
+
+			// A fresh listener decision with the same desired count confirms that a
+			// replacement is still needed.
+			ers = new(v1alpha1.EphemeralRunnerSet)
+			err = k8sClient.Get(ctx, client.ObjectKey{Name: ephemeralRunnerSet.Name, Namespace: ephemeralRunnerSet.Namespace}, ers)
+			Expect(err).NotTo(HaveOccurred(), "failed to get EphemeralRunnerSet")
+
+			updated = ers.DeepCopy()
+			updated.Spec.Replicas = 2
+			updated.Spec.PatchID = 3
+
+			err = k8sClient.Patch(ctx, updated, client.MergeFrom(ers))
+			Expect(err).NotTo(HaveOccurred(), "failed to update EphemeralRunnerSet")
+
 			runnerList = new(v1alpha1.EphemeralRunnerList)
 			Eventually(
 				func() error {
@@ -1066,6 +1119,107 @@ var _ = Describe("Test EphemeralRunnerSet controller", func() {
 			).Should(BeNil(), "2 EphemeralRunner should be created and none should be in Succeeded phase")
 		})
 
+		It("Should not create a replacement when a runner finishes ahead of the listener decrement patch", func() {
+			ers := new(v1alpha1.EphemeralRunnerSet)
+			err := k8sClient.Get(ctx, client.ObjectKey{Name: ephemeralRunnerSet.Name, Namespace: ephemeralRunnerSet.Namespace}, ers)
+			Expect(err).NotTo(HaveOccurred(), "failed to get EphemeralRunnerSet")
+
+			updated := ers.DeepCopy()
+			updated.Spec.Replicas = 4
+			updated.Spec.PatchID = 1
+
+			err = k8sClient.Patch(ctx, updated, client.MergeFrom(ers))
+			Expect(err).NotTo(HaveOccurred(), "failed to update EphemeralRunnerSet")
+
+			runnerList := new(v1alpha1.EphemeralRunnerList)
+			Eventually(
+				func() (int, error) {
+					err := listEphemeralRunnersAndRemoveFinalizers(ctx, k8sClient, runnerList, ephemeralRunnerSet.Namespace)
+					if err != nil {
+						return -1, err
+					}
+
+					return len(runnerList.Items), nil
+				},
+				ephemeralRunnerSetTestTimeout,
+				ephemeralRunnerSetTestInterval,
+			).Should(BeEquivalentTo(4), "4 EphemeralRunner should be created")
+
+			for i := range 3 {
+				updatedRunner := runnerList.Items[i].DeepCopy()
+				updatedRunner.Status.Phase = v1alpha1.EphemeralRunnerPhaseRunning
+				err = k8sClient.Status().Patch(ctx, updatedRunner, client.MergeFrom(&runnerList.Items[i]))
+				Expect(err).NotTo(HaveOccurred(), "failed to update EphemeralRunner")
+			}
+
+			updatedRunner := runnerList.Items[3].DeepCopy()
+			updatedRunner.Status.Phase = v1alpha1.EphemeralRunnerPhaseSucceeded
+			err = k8sClient.Status().Patch(ctx, updatedRunner, client.MergeFrom(&runnerList.Items[3]))
+			Expect(err).NotTo(HaveOccurred(), "failed to update EphemeralRunner")
+
+			ers = new(v1alpha1.EphemeralRunnerSet)
+			err = k8sClient.Get(ctx, client.ObjectKey{Name: ephemeralRunnerSet.Name, Namespace: ephemeralRunnerSet.Namespace}, ers)
+			Expect(err).NotTo(HaveOccurred(), "failed to get EphemeralRunnerSet")
+
+			updated = ers.DeepCopy()
+			updated.Spec.Replicas = 4
+			updated.Spec.PatchID = 2
+
+			err = k8sClient.Patch(ctx, updated, client.MergeFrom(ers))
+			Expect(err).NotTo(HaveOccurred(), "failed to update EphemeralRunnerSet")
+
+			Consistently(
+				func() (int, error) {
+					err := listEphemeralRunnersAndRemoveFinalizers(ctx, k8sClient, runnerList, ephemeralRunnerSet.Namespace)
+					if err != nil {
+						return -1, err
+					}
+
+					return len(runnerList.Items), nil
+				},
+				ephemeralRunnerSetTestTimeout,
+				ephemeralRunnerSetTestInterval,
+			).Should(BeEquivalentTo(3), "only the running EphemeralRunners should remain after stale-patch cleanup")
+
+			Consistently(
+				func() (int, error) {
+					err := listEphemeralRunnersAndRemoveFinalizers(ctx, k8sClient, runnerList, ephemeralRunnerSet.Namespace)
+					if err != nil {
+						return -1, err
+					}
+
+					return len(runnerList.Items), nil
+				},
+				12*time.Second,
+				ephemeralRunnerSetTestInterval,
+			).Should(BeEquivalentTo(3), "EphemeralRunnerSet should not create a replacement before listener decrements")
+
+			ers = new(v1alpha1.EphemeralRunnerSet)
+			err = k8sClient.Get(ctx, client.ObjectKey{Name: ephemeralRunnerSet.Name, Namespace: ephemeralRunnerSet.Namespace}, ers)
+			Expect(err).NotTo(HaveOccurred(), "failed to get EphemeralRunnerSet")
+
+			updated = ers.DeepCopy()
+			updated.Spec.Replicas = 3
+			updated.Spec.PatchID = 3
+
+			err = k8sClient.Patch(ctx, updated, client.MergeFrom(ers))
+			Expect(err).NotTo(HaveOccurred(), "failed to update EphemeralRunnerSet")
+
+			runnerList = new(v1alpha1.EphemeralRunnerList)
+			Eventually(
+				func() (int, error) {
+					err := listEphemeralRunnersAndRemoveFinalizers(ctx, k8sClient, runnerList, ephemeralRunnerSet.Namespace)
+					if err != nil {
+						return -1, err
+					}
+
+					return len(runnerList.Items), nil
+				},
+				ephemeralRunnerSetTestTimeout,
+				ephemeralRunnerSetTestInterval,
+			).Should(BeEquivalentTo(3), "EphemeralRunnerSet should converge after listener decrements")
+		})
+
 		It("Should delete idle runners, keep busy runners, and create new runners when the spec changes", func() {
 			ers := new(v1alpha1.EphemeralRunnerSet)
 			err := k8sClient.Get(ctx, client.ObjectKey{Name: ephemeralRunnerSet.Name, Namespace: ephemeralRunnerSet.Namespace}, ers)
@@ -1092,7 +1246,7 @@ var _ = Describe("Test EphemeralRunnerSet controller", func() {
 			).Should(BeEquivalentTo(3), "3 EphemeralRunner should be created")
 
 			idleRunnerNames := map[string]struct{}{}
-			for i := 0; i < 2; i++ {
+			for i := range 2 {
 				idleRunner := runnerList.Items[i].DeepCopy()
 				idleRunner.Status.Phase = v1alpha1.EphemeralRunnerPhaseRunning
 				idleRunner.Status.RunnerID = i + 101