refactor: remove use of k8s hpa (#2542)

## Description

This change removes the k8s hpa code and replaces it with direct use of
the client set instead.

## Related Issue

Relates to #2512 

## Checklist before merging

- [ ] Test, docs, adr added or updated as needed
- [ ] [Contributor Guide
Steps](https://github.com/defenseunicorns/zarf/blob/main/.github/CONTRIBUTING.md#developer-workflow)
followed

Co-authored-by: schristoff <167717759+schristoff-du@users.noreply.github.com>
Co-authored-by: razzle <razzle@defenseunicorns.com>

src/pkg/cluster/zarf.go

@@ -222,39 +222,31 @@ func (c *Cluster) RecordPackageDeployment(ctx context.Context, pkg types.ZarfPac
 
 // EnableRegHPAScaleDown enables the HPA scale down for the Zarf Registry.
 func (c *Cluster) EnableRegHPAScaleDown(ctx context.Context) error {
-	hpa, err := c.GetHPA(ctx, ZarfNamespaceName, "zarf-docker-registry")
+	hpa, err := c.Clientset.AutoscalingV2().HorizontalPodAutoscalers(ZarfNamespaceName).Get(ctx, "zarf-docker-registry", metav1.GetOptions{})
 	if err != nil {
 		return err
 	}
-
-	// Enable HPA scale down.
 	policy := autoscalingV2.MinChangePolicySelect
 	hpa.Spec.Behavior.ScaleDown.SelectPolicy = &policy
-
-	// Save the HPA changes.
-	if _, err = c.UpdateHPA(ctx, hpa); err != nil {
+	_, err = c.Clientset.AutoscalingV2().HorizontalPodAutoscalers(hpa.Namespace).Update(ctx, hpa, metav1.UpdateOptions{})
+	if err != nil {
 		return err
 	}
-
 	return nil
 }
 
 // DisableRegHPAScaleDown disables the HPA scale down for the Zarf Registry.
 func (c *Cluster) DisableRegHPAScaleDown(ctx context.Context) error {
-	hpa, err := c.GetHPA(ctx, ZarfNamespaceName, "zarf-docker-registry")
+	hpa, err := c.Clientset.AutoscalingV2().HorizontalPodAutoscalers(ZarfNamespaceName).Get(ctx, "zarf-docker-registry", metav1.GetOptions{})
 	if err != nil {
 		return err
 	}
-
-	// Disable HPA scale down.
 	policy := autoscalingV2.DisabledPolicySelect
 	hpa.Spec.Behavior.ScaleDown.SelectPolicy = &policy
-
-	// Save the HPA changes.
-	if _, err = c.UpdateHPA(ctx, hpa); err != nil {
+	_, err = c.Clientset.AutoscalingV2().HorizontalPodAutoscalers(hpa.Namespace).Update(ctx, hpa, metav1.UpdateOptions{})
+	if err != nil {
 		return err
 	}
-
 	return nil
 }
 

src/pkg/cluster/zarf_test.go

@@ -10,13 +10,15 @@ import (
 	"strings"
 	"testing"
 
-	"github.com/defenseunicorns/zarf/src/config"
-	"github.com/defenseunicorns/zarf/src/pkg/k8s"
-	"github.com/defenseunicorns/zarf/src/types"
 	"github.com/stretchr/testify/require"
+	autoscalingv2 "k8s.io/api/autoscaling/v2"
 	corev1 "k8s.io/api/core/v1"
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 	"k8s.io/client-go/kubernetes/fake"
+
+	"github.com/defenseunicorns/zarf/src/config"
+	"github.com/defenseunicorns/zarf/src/pkg/k8s"
+	"github.com/defenseunicorns/zarf/src/types"
 )
 
 // TestPackageSecretNeedsWait verifies that Zarf waits for webhooks to complete correctly.
@@ -246,3 +248,38 @@ func TestGetDeployedPackage(t *testing.T) {
 	require.NoError(t, err)
 	require.ElementsMatch(t, packages, actualList)
 }
+
+func TestRegistryHPA(t *testing.T) {
+	ctx := context.Background()
+	cs := fake.NewSimpleClientset()
+	hpa := autoscalingv2.HorizontalPodAutoscaler{
+		ObjectMeta: metav1.ObjectMeta{
+			Name:      "zarf-docker-registry",
+			Namespace: ZarfNamespaceName,
+		},
+		Spec: autoscalingv2.HorizontalPodAutoscalerSpec{
+			Behavior: &autoscalingv2.HorizontalPodAutoscalerBehavior{
+				ScaleDown: &autoscalingv2.HPAScalingRules{},
+			},
+		},
+	}
+	_, err := cs.AutoscalingV2().HorizontalPodAutoscalers(hpa.Namespace).Create(ctx, &hpa, metav1.CreateOptions{})
+	require.NoError(t, err)
+	c := &Cluster{
+		&k8s.K8s{
+			Clientset: cs,
+		},
+	}
+
+	err = c.EnableRegHPAScaleDown(ctx)
+	require.NoError(t, err)
+	enableHpa, err := cs.AutoscalingV2().HorizontalPodAutoscalers(hpa.Namespace).Get(ctx, hpa.Name, metav1.GetOptions{})
+	require.NoError(t, err)
+	require.Equal(t, autoscalingv2.MinChangePolicySelect, *enableHpa.Spec.Behavior.ScaleDown.SelectPolicy)
+
+	err = c.DisableRegHPAScaleDown(ctx)
+	require.NoError(t, err)
+	disableHpa, err := cs.AutoscalingV2().HorizontalPodAutoscalers(hpa.Namespace).Get(ctx, hpa.Name, metav1.GetOptions{})
+	require.NoError(t, err)
+	require.Equal(t, autoscalingv2.DisabledPolicySelect, *disableHpa.Spec.Behavior.ScaleDown.SelectPolicy)
+}