chore: add KeptnApp migration script

docs/docs/migrate/keptnapp/index.md

@@ -36,6 +36,20 @@ introduced in the `v1beta1` API version:
 3. Add the `app.kubernetes.io/managed-by: keptn` annotation
    to the `KeptnApp` resource if it is not already there.
 
+You can migrate your KeptnApp manually or, if you have go installed
+on your machine, use the script provided
+[here](https://github.com/keptn/lifecycle-toolkit/tree/main/lifecycle-operator/converter).
+
+```bash
+    go run convert_app.go path_to_keptnapp_to_convert path_to_desired_output_file
+```
+
+For instance, to run the example file conversion, you can do:
+
+```bash
+    go run convert_app.go example_keptnapp.yaml example_output.yaml
+```
+
 > **Note**
 Be sure that all of your application resources
 (such as

lifecycle-operator/converter/convert_app.go

@@ -0,0 +1,92 @@
+package main
+
+import (
+	"fmt"
+	"log"
+	"os"
+
+	klcv1alpha3 "github.com/keptn/lifecycle-toolkit/lifecycle-operator/apis/lifecycle/v1alpha3"
+	klcv1beta1 "github.com/keptn/lifecycle-toolkit/lifecycle-operator/apis/lifecycle/v1beta1"
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+	"sigs.k8s.io/yaml"
+)
+
+const keptnAnnotation = "app.kubernetes.io/managed-by"
+const keptn = "keptn"
+
+func main() {
+	if len(os.Args) != 3 {
+		fmt.Println("Usage: go run main.go app_cr_input_file.yaml output_file.yaml")
+		os.Exit(1)
+	}
+
+	inputFile := os.Args[1]
+	outputFile := os.Args[2]
+
+	inputContent, err := os.ReadFile(inputFile)
+	if err != nil {
+		log.Fatalf("Error reading input file: %v", err)
+	}
+
+	var keptnApp klcv1alpha3.KeptnApp
+	if err := yaml.Unmarshal(inputContent, &keptnApp); err != nil {
+		log.Fatalf("Error unmarshalling YAML: %v", err)
+	}
+
+	var keptnAppV1beta1 klcv1beta1.KeptnApp
+	if err := yaml.Unmarshal(inputContent, &keptnAppV1beta1); err != nil {
+		log.Fatalf("Error unmarshalling YAML: %v", err)
+	}
+
+	addKeptnAnnotation(&keptnAppV1beta1.ObjectMeta)
+	keptnAppV1beta1.TypeMeta.APIVersion = "lifecycle.keptn.sh/v1beta1"
+
+	// Transform KeptnAppContext
+	keptnAppContext := klcv1beta1.KeptnAppContext{
+		TypeMeta: metav1.TypeMeta{
+			Kind:       "KeptnAppContext",
+			APIVersion: "lifecycle.keptn.sh/v1beta1",
+		},
+
+		ObjectMeta: metav1.ObjectMeta{
+			Name:      keptnApp.Name,
+			Namespace: keptnApp.Namespace,
+		},
+		Spec: klcv1beta1.KeptnAppContextSpec{
+			DeploymentTaskSpec: klcv1beta1.DeploymentTaskSpec{
+
+				PreDeploymentTasks:        keptnApp.Spec.PreDeploymentTasks,
+				PreDeploymentEvaluations:  keptnApp.Spec.PreDeploymentEvaluations,
+				PostDeploymentTasks:       keptnApp.Spec.PostDeploymentTasks,
+				PostDeploymentEvaluations: keptnApp.Spec.PostDeploymentEvaluations,
+			},
+		},
+	}
+
+	// Convert to YAML and write to output file
+	keptnAppV1beta1YAML, err := yaml.Marshal(keptnAppV1beta1)
+	if err != nil {
+		log.Fatalf("Error marshalling to YAML: %v", err)
+	}
+
+	keptnAppContextYAML, err := yaml.Marshal(keptnAppContext)
+	if err != nil {
+		log.Fatalf("Error marshalling to YAML: %v", err)
+	}
+
+	// Combine and write to output file
+	outputContent := fmt.Sprintf("%s\n---\n%s", string(keptnAppV1beta1YAML), string(keptnAppContextYAML))
+	if err := os.WriteFile(outputFile, []byte(outputContent), 0644); err != nil {
+		log.Fatalf("Error writing to output file: %v", err)
+	}
+
+	fmt.Println("Transformation completed. Output written to", outputFile)
+}
+
+func addKeptnAnnotation(resource *metav1.ObjectMeta) {
+	annotations := resource.GetAnnotations()
+	if annotations == nil {
+		resource.Annotations = make(map[string]string, 1)
+	}
+	resource.Annotations[keptnAnnotation] = keptn
+}

lifecycle-operator/converter/convert_app_test.go

@@ -0,0 +1,76 @@
+package main
+
+import (
+	"os"
+	"testing"
+
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+)
+
+const inputFileName = "example_keptnapp.yaml"
+const outputFileName = "example_output.yaml"
+
+func TestMigration(t *testing.T) {
+	// Set up a temporary directory for test files
+	// Run the main function with test arguments
+	inputFile := inputFileName
+	outputFile := outputFileName
+	os.Args = []string{"main", inputFile, outputFile}
+	main()
+
+	// Read the expected output file content
+	expectedOutput, err := os.ReadFile(outputFile)
+	if err != nil {
+		t.Fatalf("Error reading expected output file: %v", err)
+	}
+
+	// Read the actual output file content
+	actualOutput, err := os.ReadFile(outputFile)
+	if err != nil {
+		t.Fatalf("Error reading actual output file: %v", err)
+	}
+
+	// Assert that the actual output file content matches the expected output
+	if string(actualOutput) != string(expectedOutput) {
+		t.Errorf("Unexpected output content. Expected:\n%s\n\nActual:\n%s", string(expectedOutput), string(actualOutput))
+	}
+}
+
+func TestAddKeptnAnnotation(t *testing.T) {
+	// Test case 1: Annotations map is nil
+	t.Run("AnnotationsMapIsNil", func(t *testing.T) {
+		resource := &metav1.ObjectMeta{}
+		addKeptnAnnotation(resource)
+
+		// Check if the annotation was added
+		if value, exists := resource.Annotations[keptnAnnotation]; !exists || value != keptn {
+			t.Errorf("Annotation not added correctly. Expected: %s=%s, Actual: %s=%s", keptnAnnotation, keptn, keptnAnnotation, value)
+		}
+	})
+
+	// Test case 2: Annotations map is not nil
+	t.Run("AnnotationsMapIsNotNil", func(t *testing.T) {
+		// Existing annotations
+		existingAnnotations := map[string]string{
+			"existing-key": "existing-value",
+		}
+
+		resource := &metav1.ObjectMeta{
+			Annotations: existingAnnotations,
+		}
+
+		addKeptnAnnotation(resource)
+
+		// Check if the annotation was added
+		if value, exists := resource.Annotations[keptnAnnotation]; !exists || value != keptn {
+			t.Errorf("Annotation not added correctly. Expected: %s=%s, Actual: %s=%s", keptnAnnotation, keptn, keptnAnnotation, value)
+		}
+
+		// Check if existing annotations are preserved
+		for key, value := range existingAnnotations {
+			if resource.Annotations[key] != value {
+				t.Errorf("Existing annotation %s=%s is not preserved", key, value)
+			}
+		}
+	})
+}

lifecycle-operator/converter/example_keptnapp.yaml

@@ -0,0 +1,18 @@
+apiVersion: lifecycle.keptn.sh/v1alpha3
+kind: KeptnApp
+metadata:
+  name: "some-keptn-app"
+  namespace: "my-app-ns"
+spec:
+  version: "1.2.3"
+  workloads:
+    - name: podtato-head-left-arm
+      version: 0.2.7
+  preDeploymentTasks:
+    - pre-deployment-task
+  preDeploymentEvaluations:
+    - pre-deployment-evaluation
+  postDeploymentTasks:
+    - post-deployment-task
+  postDeploymentEvaluations:
+    - post-deployment-evaluation

lifecycle-operator/converter/example_output.yaml

@@ -0,0 +1,32 @@
+apiVersion: lifecycle.keptn.sh/v1beta1
+kind: KeptnApp
+metadata:
+  annotations:
+    app.kubernetes.io/managed-by: keptn
+  creationTimestamp: null
+  name: some-keptn-app
+  namespace: my-app-ns
+spec:
+  version: 1.2.3
+  workloads:
+    - name: podtato-head-left-arm
+      version: 0.2.7
+status: {}
+
+---
+apiVersion: lifecycle.keptn.sh/v1beta1
+kind: KeptnAppContext
+metadata:
+  creationTimestamp: null
+  name: some-keptn-app
+  namespace: my-app-ns
+spec:
+  postDeploymentEvaluations:
+    - post-deployment-evaluation
+  postDeploymentTasks:
+    - post-deployment-task
+  preDeploymentEvaluations:
+    - pre-deployment-evaluation
+  preDeploymentTasks:
+    - pre-deployment-task
+status: {}