fix: retry Experiment ReplicaSet scaling conflict errors

Signed-off-by: Jesse Suen <[email protected]>

experiments/replicaset.go

@@ -6,12 +6,10 @@ import (
 	"fmt"
 	"time"
 
-	"github.com/argoproj/argo-rollouts/utils/defaults"
-	timeutil "github.com/argoproj/argo-rollouts/utils/time"
-
 	log "github.com/sirupsen/logrus"
 	appsv1 "k8s.io/api/apps/v1"
 	"k8s.io/apimachinery/pkg/api/errors"
+	k8serrors "k8s.io/apimachinery/pkg/api/errors"
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 	"k8s.io/apimachinery/pkg/labels"
 	patchtypes "k8s.io/apimachinery/pkg/types"
@@ -20,10 +18,12 @@ import (
 
 	"github.com/argoproj/argo-rollouts/pkg/apis/rollouts/v1alpha1"
 	"github.com/argoproj/argo-rollouts/utils/conditions"
+	"github.com/argoproj/argo-rollouts/utils/defaults"
 	experimentutil "github.com/argoproj/argo-rollouts/utils/experiment"
 	logutil "github.com/argoproj/argo-rollouts/utils/log"
 	"github.com/argoproj/argo-rollouts/utils/record"
 	replicasetutil "github.com/argoproj/argo-rollouts/utils/replicaset"
+	timeutil "github.com/argoproj/argo-rollouts/utils/time"
 )
 
 const (
@@ -268,7 +268,11 @@ func (ec *experimentContext) scaleReplicaSetAndRecordEvent(rs *appsv1.ReplicaSet
 	}
 	scaled, newRS, err := ec.scaleReplicaSet(rs, newScale, scalingOperation)
 	if err != nil {
-		// TODO(jessesuen): gracefully handle conflict issues
+		if !k8serrors.IsConflict(err) {
+			ec.log.Warnf("Retrying ReplicaSet '%s' scaling: %s", rs.Name, err)
+			ec.enqueueExperimentAfter(ec.ex, time.Second)
+			return false, nil, nil
+		}
 		msg := fmt.Sprintf("Failed to scale %s %s: %v", rs.Name, scalingOperation, err)
 		ec.recorder.Warnf(ec.ex, record.EventOptions{EventReason: "ReplicaSetUpdateError"}, msg)
 	} else {