Add previewReplicaCount to BG

controller/bluegreen.go

@@ -42,7 +42,7 @@ func (c *Controller) rolloutBlueGreen(r *v1alpha1.Rollout, rsList []*appsv1.Repl
 
 	if previewSvc != nil {
 		logCtx.Infof("Reconciling preview service '%s'", previewSvc.Name)
-		if !annotations.IsSaturated(r, newRS) {
+		if !replicasetutil.ReadyForPreview(r, newRS, allRSs) {
 			logutil.WithRollout(r).Infof("New RS '%s' is not fully saturated", newRS.Name)
 			return c.syncRolloutStatusBlueGreen(oldRSs, newRS, previewSvc, activeSvc, r, false)
 		}
@@ -197,6 +197,12 @@ func (c *Controller) syncRolloutStatusBlueGreen(oldRSs []*appsv1.ReplicaSet, new
 	}
 
 	pauseStartTime, paused := calculatePauseStatus(r, addPause)
+	newStatus.BlueGreen.ScaleUpPreviewCheckPoint = r.Status.BlueGreen.ScaleUpPreviewCheckPoint
+	if paused && r.Spec.Strategy.BlueGreenStrategy.PreviewReplicaCount != nil {
+		newStatus.BlueGreen.ScaleUpPreviewCheckPoint = true
+	} else if newRS != nil && activeRS != nil && activeRS.Name == newRS.Name {
+		newStatus.BlueGreen.ScaleUpPreviewCheckPoint = false
+	}
 	newStatus.PauseStartTime = pauseStartTime
 	newStatus = c.calculateRolloutConditions(r, newStatus, allRSs, newRS)
 	return c.persistRolloutStatus(r, &newStatus, &paused)
@@ -233,8 +239,12 @@ func (c *Controller) scaleBlueGreen(rollout *v1alpha1.Rollout, newRS *appsv1.Rep
 	}
 
 	if newRS != nil {
-		if *(newRS.Spec.Replicas) != rolloutReplicas {
-			_, _, err := c.scaleReplicaSetAndRecordEvent(newRS, rolloutReplicas, rollout)
+		newRSReplicaCount, err := replicasetutil.NewRSNewReplicas(rollout, allRS, newRS)
+		if err != nil {
+			return err
+		}
+		if *(newRS.Spec.Replicas) != newRSReplicaCount {
+			_, _, err := c.scaleReplicaSetAndRecordEvent(newRS, newRSReplicaCount, rollout)
 			return err
 		}
 	}

controller/sync.go

@@ -207,6 +207,8 @@ func (c *Controller) getNewReplicaSet(rollout *v1alpha1.Rollout, rsList, oldRSs
 
 // sync is responsible for reconciling rollouts on scaling events.
 func (c *Controller) sync(r *v1alpha1.Rollout, rsList []*appsv1.ReplicaSet) error {
+	logCtx := logutil.WithRollout(r)
+	logCtx.Info("Reconciling scaling event")
 	newRS, oldRSs, err := c.getAllReplicaSetsAndSyncRevision(r, rsList, false)
 	if err != nil {
 		return err

controller/sync_test.go

@@ -20,6 +20,7 @@ import (
 
 func newRolloutWithStatus(name string, replicas int, revisionHistoryLimit *int32, selector map[string]string) *v1alpha1.Rollout {
 	rollout := newRollout(name, replicas, revisionHistoryLimit, selector)
+	rollout.Spec.Strategy.BlueGreenStrategy = &v1alpha1.BlueGreenStrategy{}
 	return rollout
 }
 
@@ -46,7 +47,7 @@ func rs(name string, replicas int, selector map[string]string, timestamp metav1.
 	}
 }
 
-func TestScaleBlueGreen(t *testing.T) {
+func  TestScaleBlueGreen(t *testing.T) {
 	newTimestamp := metav1.Date(2016, 5, 20, 3, 0, 0, 0, time.UTC)
 	oldTimestamp := metav1.Date(2016, 5, 20, 2, 0, 0, 0, time.UTC)
 	olderTimestamp := metav1.Date(2016, 5, 20, 1, 0, 0, 0, time.UTC)

manifests/crds/rollout-crd.yaml

@@ -75,6 +75,13 @@ spec:
                       description: Name of the service that the rollout modifies as
                         the active service.
                       type: string
+                    previewReplicaCount:
+                      description: PreviewReplica the number of replicas to run under
+                        the preview service before the switchover. Once the rollout
+                        is resumed the new replicaset will be full scaled up before
+                        the switch occurs
+                      format: int32
+                      type: integer
                     previewService:
                       description: Name of the service that the rollout modifies as
                         the preview service.
@@ -148,6 +155,11 @@ spec:
                     service is serving traffic to
                   type: string
                 scaleDownDelayStartTime: {}
+                scaleUpPreviewCheckPoint:
+                  description: ScaleUpPreviewCheckPoint indicates that the Replicaset
+                    receiving traffic from the preview service is ready to be scaled
+                    up after the rollout is unpaused
+                  type: boolean
             canary:
               description: CanaryStatus status fields that only pertain to the canary
                 rollout

manifests/install.yaml

@@ -76,6 +76,13 @@ spec:
                       description: Name of the service that the rollout modifies as
                         the active service.
                       type: string
+                    previewReplicaCount:
+                      description: PreviewReplica the number of replicas to run under
+                        the preview service before the switchover. Once the rollout
+                        is resumed the new replicaset will be full scaled up before
+                        the switch occurs
+                      format: int32
+                      type: integer
                     previewService:
                       description: Name of the service that the rollout modifies as
                         the preview service.
@@ -149,6 +156,11 @@ spec:
                     service is serving traffic to
                   type: string
                 scaleDownDelayStartTime: {}
+                scaleUpPreviewCheckPoint:
+                  description: ScaleUpPreviewCheckPoint indicates that the Replicaset
+                    receiving traffic from the preview service is ready to be scaled
+                    up after the rollout is unpaused
+                  type: boolean
             canary:
               description: CanaryStatus status fields that only pertain to the canary
                 rollout

manifests/namespace-install.yaml

@@ -76,6 +76,13 @@ spec:
                       description: Name of the service that the rollout modifies as
                         the active service.
                       type: string
+                    previewReplicaCount:
+                      description: PreviewReplica the number of replicas to run under
+                        the preview service before the switchover. Once the rollout
+                        is resumed the new replicaset will be full scaled up before
+                        the switch occurs
+                      format: int32
+                      type: integer
                     previewService:
                       description: Name of the service that the rollout modifies as
                         the preview service.
@@ -149,6 +156,11 @@ spec:
                     service is serving traffic to
                   type: string
                 scaleDownDelayStartTime: {}
+                scaleUpPreviewCheckPoint:
+                  description: ScaleUpPreviewCheckPoint indicates that the Replicaset
+                    receiving traffic from the preview service is ready to be scaled
+                    up after the rollout is unpaused
+                  type: boolean
             canary:
               description: CanaryStatus status fields that only pertain to the canary
                 rollout

pkg/apis/rollouts/v1alpha1/types.go

@@ -77,6 +77,10 @@ type BlueGreenStrategy struct {
 	// Name of the service that the rollout modifies as the preview service.
 	// +optional
 	PreviewService string `json:"previewService,omitempty"`
+	// PreviewReplica the number of replicas to run under the preview service before the switchover. Once the rollout is
+	// resumed the new replicaset will be full scaled up before the switch occurs
+	// +optional
+	PreviewReplicaCount *int32 `json:"previewReplicaCount,omitempty"`
 	// ScaleDownDelaySeconds adds a delay before scaling down the previous replicaset. See
 	// https://github.com/argoproj/argo-rollouts/issues/19#issuecomment-476329960 for more information
 	// +optional
@@ -124,12 +128,6 @@ type CanaryStep struct {
 	Pause *RolloutPause `json:"pause,omitempty"`
 }
 
-// SetPreview empty struct to indicate the SetPreview step
-type SetPreview struct{}
-
-// SwitchActive empty struct to indicate the SetActive step
-type SwitchActive struct{}
-
 // RolloutPause defines a pause stage for a rollout
 type RolloutPause struct {
 	// Duration the amount of time to wait before moving to the next step.
@@ -201,6 +199,9 @@ type BlueGreenStatus struct {
 	// ScaleDownDelayStartTime indicates the start of the scaleDownDelay
 	// +optional
 	ScaleDownDelayStartTime *metav1.Time `json:"scaleDownDelayStartTime,omitempty"`
+	// ScaleUpPreviewCheckPoint indicates that the Replicaset receiving traffic from the preview service is ready to be scaled up after the rollout is unpaused
+	// +optional
+	ScaleUpPreviewCheckPoint bool `json:"scaleUpPreviewCheckPoint,omitempty""`
 }
 
 // CanaryStatus status fields that only pertain to the canary rollout

utils/replicaset/bluegreen.go

@@ -0,0 +1,34 @@
+package replicaset
+
+import (
+	appsv1 "k8s.io/api/apps/v1"
+
+	v1alpha1 "github.com/argoproj/argo-rollouts/pkg/apis/rollouts/v1alpha1"
+)
+
+// GetActiveReplicaSet finds the replicaset that is serving traffic from the active service or returns nil
+func GetActiveReplicaSet(allRS []*appsv1.ReplicaSet, activeSelector string) *appsv1.ReplicaSet {
+	if activeSelector == "" {
+		return nil
+	}
+	for _, rs := range allRS {
+		if rs == nil {
+			continue
+		}
+		if podHash, ok := rs.Labels[v1alpha1.DefaultRolloutUniqueLabelKey]; ok {
+			if podHash == activeSelector {
+				return rs
+			}
+		}
+	}
+	return nil
+}
+
+func ReadyForPreview(rollout *v1alpha1.Rollout, newRS *appsv1.ReplicaSet, allRSs []*appsv1.ReplicaSet) bool {
+	newRSReplicaCount, err := NewRSNewReplicas(rollout, allRSs, newRS)
+	if err != nil {
+		return false
+	}
+	return *(newRS.Spec.Replicas) == newRSReplicaCount &&
+		newRS.Status.AvailableReplicas == newRSReplicaCount
+}

utils/replicaset/bluegreen_test.go

@@ -0,0 +1,66 @@
+package replicaset
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	appsv1 "k8s.io/api/apps/v1"
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+	"k8s.io/utils/pointer"
+
+	"github.com/argoproj/argo-rollouts/pkg/apis/rollouts/v1alpha1"
+)
+
+func TestGetActiveReplicaSet(t *testing.T) {
+	assert.Nil(t, GetActiveReplicaSet(nil, ""))
+	rs1 := &appsv1.ReplicaSet{
+		ObjectMeta: metav1.ObjectMeta{
+			Labels: map[string]string{v1alpha1.DefaultRolloutUniqueLabelKey: "abcd"},
+		},
+	}
+	assert.Nil(t, GetActiveReplicaSet([]*appsv1.ReplicaSet{rs1}, "1234"))
+
+	rs2 := &appsv1.ReplicaSet{
+		ObjectMeta: metav1.ObjectMeta{
+			Labels: map[string]string{v1alpha1.DefaultRolloutUniqueLabelKey: "1234"},
+		},
+	}
+	assert.Equal(t, rs2, GetActiveReplicaSet([]*appsv1.ReplicaSet{nil, rs1, rs2}, "1234"))
+}
+
+func TestReadyForPreview(t *testing.T) {
+	rollout := &v1alpha1.Rollout{
+		Spec: v1alpha1.RolloutSpec{
+			Strategy: v1alpha1.RolloutStrategy{
+				BlueGreenStrategy: &v1alpha1.BlueGreenStrategy{},
+			},
+		},
+	}
+
+	readyRS := &appsv1.ReplicaSet{
+		ObjectMeta: metav1.ObjectMeta{
+			Labels: map[string]string{v1alpha1.DefaultRolloutUniqueLabelKey: "abcd"},
+		},
+		Spec: appsv1.ReplicaSetSpec{
+			Replicas: pointer.Int32Ptr(1),
+		},
+		Status: appsv1.ReplicaSetStatus{
+			AvailableReplicas: 1,
+		},
+	}
+
+	notReadyRS := &appsv1.ReplicaSet{
+		ObjectMeta: metav1.ObjectMeta{
+			Labels: map[string]string{v1alpha1.DefaultRolloutUniqueLabelKey: "abcd"},
+		},
+		Spec: appsv1.ReplicaSetSpec{
+			Replicas: pointer.Int32Ptr(1),
+		},
+		Status: appsv1.ReplicaSetStatus{
+			AvailableReplicas: 0,
+		},
+	}
+	assert.False(t, ReadyForPreview(&v1alpha1.Rollout{}, nil, nil))
+	assert.True(t, ReadyForPreview(rollout, readyRS, []*appsv1.ReplicaSet{readyRS}))
+	assert.False(t, ReadyForPreview(rollout, notReadyRS, []*appsv1.ReplicaSet{readyRS}))
+}