From 3ba77087e5fd48a38e7ed6cd9eef44b5a854cf25 Mon Sep 17 00:00:00 2001
From: Alex Collins <alex_collins@intuit.com>
Date: Thu, 12 Aug 2021 15:21:35 -0700
Subject: [PATCH] fix: Prevent scaling from deleting pods

---
 api/v1alpha1/step_spec.go              |  6 ++++++
 api/v1alpha1/step_spec_test.go         | 13 +++++++++++++
 manager/controllers/step_controller.go |  7 +++----
 3 files changed, 22 insertions(+), 4 deletions(-)
 create mode 100644 api/v1alpha1/step_spec_test.go

diff --git a/api/v1alpha1/step_spec.go b/api/v1alpha1/step_spec.go
index 751e4fc7..497938a0 100644
--- a/api/v1alpha1/step_spec.go
+++ b/api/v1alpha1/step_spec.go
@@ -90,3 +90,9 @@ func (in StepSpec) CalculateReplicas(pending int) int {
 	}
 	return in.Scale.Calculate(pending)
 }
+
+func (in StepSpec) WithOutReplicas() StepSpec {
+	x := *in.DeepCopy()
+	x.Replicas = 0
+	return x
+}
diff --git a/api/v1alpha1/step_spec_test.go b/api/v1alpha1/step_spec_test.go
new file mode 100644
index 00000000..076286c5
--- /dev/null
+++ b/api/v1alpha1/step_spec_test.go
@@ -0,0 +1,13 @@
+package v1alpha1
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestStepSpec_WithOutReplicas(t *testing.T) {
+	in := StepSpec{Replicas: 1, Name: "foo"}.WithOutReplicas()
+	assert.Zero(t, in.Replicas)
+	assert.Equal(t, "foo", in.Name)
+}
diff --git a/manager/controllers/step_controller.go b/manager/controllers/step_controller.go
index 448c2dda..f097925f 100644
--- a/manager/controllers/step_controller.go
+++ b/manager/controllers/step_controller.go
@@ -61,10 +61,9 @@ type hash struct {
 
 var (
 	clusterName = os.Getenv(dfv1.EnvClusterName)
-	debug = os.Getenv(dfv1.EnvDebug) == "true"
+	debug       = os.Getenv(dfv1.EnvDebug) == "true"
 )
 
-
 func init() {
 	logger.Info("config", "clusterName", clusterName, "debug", debug)
 }
@@ -129,7 +128,7 @@ func (r *StepReconciler) Reconcile(ctx context.Context, req ctrl.Request) (ctrl.
 	}
 
 	selector, _ := labels.Parse(dfv1.KeyPipelineName + "=" + pipelineName + "," + dfv1.KeyStepName + "=" + stepName)
-	hash := util.MustHash(hash{runnerImage, step.Spec})
+	hash := util.MustHash(hash{runnerImage, step.Spec.WithOutReplicas()}) // we must remove data (e.g. replicas) which does not change the pod, otherwise it would cause the pod to be re-created all the time
 	oldStatus := step.Status.DeepCopy()
 	step.Status.Phase, step.Status.Reason, step.Status.Message = dfv1.StepUnknown, "", ""
 	step.Status.Selector = selector.String()
@@ -179,7 +178,7 @@ func (r *StepReconciler) Reconcile(ctx context.Context, req ctrl.Request) (ctrl.
 				Spec: step.GetPodSpec(
 					dfv1.GetPodSpecReq{
 						ClusterName:      clusterName,
-						Debug: debug,
+						Debug:            debug,
 						PipelineName:     pipelineName,
 						Namespace:        step.Namespace,
 						Replica:          int32(replica),