feat: [SKU-modularization] Get SKU Handler (kaito-project#518)

**Reason for Change**:
- Reading the CLOUD_PROVIDER environment variable and initializing the
respective SKUHandler to access the correct list of gpu skus

**Requirements**

- [ ] added unit tests and e2e tests (if applicable).

**Issue Fixed**:
<!-- If this PR fixes GitHub issue 4321, add "Fixes #4321" to the next
line. -->

**Notes for Reviewers**:
This PR does not change anything in the current implementation to keep
things clean. The next PR will get rid of sku_config from v1alpha1 and
carry out necessary refactoring and test updates.

pkg/sku/cloud_sku_handler.go

@@ -3,6 +3,10 @@
 
 package sku
 
+import (
+	"github.com/azure/kaito/pkg/utils/consts"
+)
+
 type CloudSKUHandler interface {
 	GetSupportedSKUs() []string
 	GetGPUConfigs() map[string]GPUConfig
@@ -14,3 +18,14 @@ type GPUConfig struct {
 	GPUMem   int
 	GPUModel string
 }
+
+func GetCloudSKUHandler(cloud string) CloudSKUHandler {
+	switch cloud {
+	case consts.AzureCloudName:
+		return NewAzureSKUHandler()
+	case consts.AWSCloudName:
+		return NewAwsSKUHandler()
+	default:
+		return nil
+	}
+}

pkg/utils/common.go

@@ -10,7 +10,9 @@ import (
 
 	"gopkg.in/yaml.v2"
 	"k8s.io/apimachinery/pkg/runtime"
+	"knative.dev/pkg/apis"
 
+	"github.com/azure/kaito/pkg/sku"
 	"github.com/azure/kaito/pkg/utils/consts"
 )
 
@@ -101,3 +103,19 @@ func GetReleaseNamespace() (string, error) {
 	}
 	return "", fmt.Errorf("failed to determine release namespace from file %s and env var %s", namespaceFilePath, consts.DefaultReleaseNamespaceEnvVar)
 }
+
+func GetSKUHandler() (sku.CloudSKUHandler, error) {
+	// Get the cloud provider from the environment
+	provider := os.Getenv("CLOUD_PROVIDER")
+
+	if provider == "" {
+		return nil, apis.ErrMissingField("CLOUD_PROVIDER environment variable must be set")
+	}
+	// Select the correct SKU handler based on the cloud provider
+	skuHandler := sku.GetCloudSKUHandler(provider)
+	if skuHandler == nil {
+		return nil, apis.ErrInvalidValue(fmt.Sprintf("Unsupported cloud provider %s", provider), "CLOUD_PROVIDER")
+	}
+
+	return skuHandler, nil
+}

pkg/utils/consts/consts.go

@@ -8,4 +8,6 @@ const (
 	WorkspaceFinalizer            = "workspace.finalizer.kaito.sh"
 	DefaultReleaseNamespaceEnvVar = "RELEASE_NAMESPACE"
 	FeatureFlagKarpenter          = "Karpenter"
+	AzureCloudName                = "azure"
+	AWSCloudName                  = "aws"
 )