feat: add generic kubernetest resource management api (#42)

Author: reshnm

README.md

@@ -339,6 +339,82 @@ env := testing.NewEnvironmentBuilder().
 env.ShouldReconcile(testing.RequestFromStrings("testresource"))
 ```
 
+### Kubernetes resource management
+
+The `pkg/resource` package contains some useful functions for working with Kubernetes resources. The `Mutator` interface can be used to modify resources in a generic way. It is used by the `Mutate` function, which takes a resource and a mutator and applies the mutator to the resource.
+The package also contains convenience types for the most common resource types, e.g. `ConfigMap`, `Secret`, `ClusterRole`, `ClusterRoleBinding`, etc. These types implement the `Mutator` interface and can be used to modify the corresponding resources.
+
+#### Examples
+
+Create or update a `ConfigMap`, a `ServiceAccount` and a `Deployment` using the `Mutator` interface:
+
+```go
+type myDeploymentMutator struct {
+}
+
+var _ resource.Mutator[*appsv1.Deployment] = &myDeploymentMutator{}
+
+func newDeploymentMutator() resources.Mutator[*appsv1.Deployment] {
+	return &MyDeploymentMutator{}
+}
+
+func (m *MyDeploymentMutator) String() string {
+	return "deployment default/test"
+}
+
+func (m *MyDeploymentMutator) Empty() *appsv1.Deployment {
+	return &appsv1.Deployment{
+		ObjectMeta: metav1.ObjectMeta{	
+			Name:      "test",
+			Namespace: "default",
+		},
+	}
+}
+
+func (m *MyDeploymentMutator) Mutate(deployment *appsv1.Deployment) error {
+	// create one container with an image
+	deployment.Spec.Template.Spec.Containers = []corev1.Container{
+		{
+			Name:  "test",
+			Image: "test-image:latest",
+		},
+	}
+	return nil
+}
+
+
+func ReconcileResources(ctx context.Context, client client.Client) error {
+	configMapResource := resource.NewConfigMap("my-configmap", "my-namespace", map[string]string{)
+		"label1": "value1",
+		"label2": "value2",
+	}, nil)
+
+	serviceAccountResource := resource.NewServiceAccount("my-serviceaccount", "my-namespace", nil, nil)
+	
+	myDeploymentMutator := newDeploymentMutator()
+	
+	var err error
+	
+	err = resources.CreateOrUpdateResource(ctx, client, configMapResource)
+	if err != nil {
+		return err
+	}
+	
+	resources.CreateOrUpdateResource(ctx, client, serviceAccountResource)
+	if err != nil {
+		return err
+	}
+	
+	err = resources.CreateOrUpdateResource(ctx, client, myDeploymentMutator)
+	if err != nil {
+		return err
+	}
+	
+	return nil
+}
+
+```
+
 ## Support, Feedback, Contributing
 
 This project is open to feature requests/suggestions, bug reports etc. via [GitHub issues](https://github.com/openmcp-project/controller-utils/issues). Contribution and feedback are encouraged and always welcome. For more information about how to contribute, the project structure, as well as additional contribution information, see our [Contribution Guidelines](CONTRIBUTING.md).

pkg/resources/clusterrole.go

@@ -0,0 +1,47 @@
+package resources
+
+import (
+	"fmt"
+
+	"sigs.k8s.io/controller-runtime/pkg/client"
+
+	v1 "k8s.io/api/rbac/v1"
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+)
+
+type ClusterRoleMutator struct {
+	Name  string
+	Rules []v1.PolicyRule
+	meta  Mutator[client.Object]
+}
+
+var _ Mutator[*v1.ClusterRole] = &ClusterRoleMutator{}
+
+func NewClusterRoleMutator(name string, rules []v1.PolicyRule, labels map[string]string, annotations map[string]string) Mutator[*v1.ClusterRole] {
+	return &ClusterRoleMutator{
+		Name:  name,
+		Rules: rules,
+		meta:  NewMetadataMutator(labels, annotations),
+	}
+}
+
+func (m *ClusterRoleMutator) String() string {
+	return fmt.Sprintf("clusterrole %s", m.Name)
+}
+
+func (m *ClusterRoleMutator) Empty() *v1.ClusterRole {
+	return &v1.ClusterRole{
+		TypeMeta: metav1.TypeMeta{
+			APIVersion: "rbac.authorization.k8s.io/v1",
+			Kind:       "ClusterRole",
+		},
+		ObjectMeta: metav1.ObjectMeta{
+			Name: m.Name,
+		},
+	}
+}
+
+func (m *ClusterRoleMutator) Mutate(r *v1.ClusterRole) error {
+	r.Rules = m.Rules
+	return m.meta.Mutate(r)
+}

pkg/resources/clusterrole_test.go

@@ -0,0 +1,84 @@
+package resources_test
+
+import (
+	"context"
+
+	. "github.com/onsi/ginkgo/v2"
+	. "github.com/onsi/gomega"
+	v1 "k8s.io/api/rbac/v1"
+	"k8s.io/apimachinery/pkg/runtime"
+	"sigs.k8s.io/controller-runtime/pkg/client"
+
+	"github.com/openmcp-project/controller-utils/pkg/resources"
+	"github.com/openmcp-project/controller-utils/pkg/testing"
+)
+
+var _ = Describe("ClusterRoleMutator", func() {
+	var (
+		ctx         context.Context
+		fakeClient  client.WithWatch
+		scheme      *runtime.Scheme
+		rules       []v1.PolicyRule
+		labels      map[string]string
+		annotations map[string]string
+		mutator     resources.Mutator[*v1.ClusterRole]
+	)
+
+	BeforeEach(func() {
+		ctx = context.TODO()
+
+		// Create a scheme and register the rbac/v1 API
+		scheme = runtime.NewScheme()
+		Expect(v1.AddToScheme(scheme)).To(Succeed())
+
+		// Initialize the fake client
+		var err error
+		fakeClient, err = testing.GetFakeClient(scheme)
+		Expect(err).ToNot(HaveOccurred())
+
+		// Define rules, labels, and annotations
+		rules = []v1.PolicyRule{
+			{
+				APIGroups: []string{""},
+				Resources: []string{"pods"},
+				Verbs:     []string{"get", "list"},
+			},
+		}
+		labels = map[string]string{"key1": "value1"}
+		annotations = map[string]string{"annotation1": "value1"}
+
+		// Create a cluster role mutator
+		mutator = resources.NewClusterRoleMutator("test-clusterrole", rules, labels, annotations)
+	})
+
+	It("should create an empty cluster role with correct metadata", func() {
+		clusterRole := mutator.Empty()
+
+		Expect(clusterRole.Name).To(Equal("test-clusterrole"))
+		Expect(clusterRole.APIVersion).To(Equal("rbac.authorization.k8s.io/v1"))
+		Expect(clusterRole.Kind).To(Equal("ClusterRole"))
+	})
+
+	It("should apply rules using Mutate", func() {
+		clusterRole := mutator.Empty()
+
+		// Apply the mutator's Mutate method
+		Expect(mutator.Mutate(clusterRole)).To(Succeed())
+
+		// Verify that the rules are applied
+		Expect(clusterRole.Rules).To(Equal(rules))
+	})
+
+	It("should create and retrieve the cluster role using the fake client", func() {
+		clusterRole := mutator.Empty()
+		Expect(mutator.Mutate(clusterRole)).To(Succeed())
+
+		// Create the cluster role in the fake client
+		Expect(fakeClient.Create(ctx, clusterRole)).To(Succeed())
+
+		// Retrieve the cluster role from the fake client and verify it
+		retrievedClusterRole := &v1.ClusterRole{}
+		Expect(fakeClient.Get(ctx, client.ObjectKey{Name: "test-clusterrole"}, retrievedClusterRole)).To(Succeed())
+		Expect(retrievedClusterRole).To(Equal(clusterRole))
+	})
+})

pkg/resources/clusterrolebinding.go

@@ -0,0 +1,50 @@
+package resources
+
+import (
+	"fmt"
+
+	"sigs.k8s.io/controller-runtime/pkg/client"
+
+	v1 "k8s.io/api/rbac/v1"
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+)
+
+type ClusterRoleBindingMutator struct {
+	ClusterRoleBindingName string
+	RoleRef                v1.RoleRef
+	Subjects               []v1.Subject
+	meta                   Mutator[client.Object]
+}
+
+var _ Mutator[*v1.ClusterRoleBinding] = &ClusterRoleBindingMutator{}
+
+func NewClusterRoleBindingMutator(clusterRoleBindingName string, subjects []v1.Subject, roleRef v1.RoleRef, labels map[string]string, annotations map[string]string) Mutator[*v1.ClusterRoleBinding] {
+	return &ClusterRoleBindingMutator{
+		ClusterRoleBindingName: clusterRoleBindingName,
+		RoleRef:                roleRef,
+		Subjects:               subjects,
+		meta:                   NewMetadataMutator(labels, annotations),
+	}
+}
+
+func (m *ClusterRoleBindingMutator) String() string {
+	return fmt.Sprintf("clusterrolebinding %s", m.ClusterRoleBindingName)
+}
+
+func (m *ClusterRoleBindingMutator) Empty() *v1.ClusterRoleBinding {
+	return &v1.ClusterRoleBinding{
+		TypeMeta: metav1.TypeMeta{
+			APIVersion: "rbac.authorization.k8s.io/v1",
+			Kind:       "ClusterRoleBinding",
+		},
+		ObjectMeta: metav1.ObjectMeta{
+			Name: m.ClusterRoleBindingName,
+		},
+	}
+}
+
+func (m *ClusterRoleBindingMutator) Mutate(r *v1.ClusterRoleBinding) error {
+	r.RoleRef = m.RoleRef
+	r.Subjects = m.Subjects
+	return m.meta.Mutate(r)
+}

pkg/resources/clusterrolebinding_test.go

@@ -0,0 +1,87 @@
+package resources_test
+
+import (
+	"context"
+
+	. "github.com/onsi/ginkgo/v2"
+	. "github.com/onsi/gomega"
+	v1 "k8s.io/api/rbac/v1"
+	"k8s.io/apimachinery/pkg/runtime"
+	"sigs.k8s.io/controller-runtime/pkg/client"
+
+	"github.com/openmcp-project/controller-utils/pkg/resources"
+	"github.com/openmcp-project/controller-utils/pkg/testing"
+)
+
+var _ = Describe("ClusterRoleBindingMutator", func() {
+	var (
+		ctx         context.Context
+		fakeClient  client.WithWatch
+		scheme      *runtime.Scheme
+		subjects    []v1.Subject
+		roleRef     v1.RoleRef
+		labels      map[string]string
+		annotations map[string]string
+		mutator     resources.Mutator[*v1.ClusterRoleBinding]
+	)
+
+	BeforeEach(func() {
+		ctx = context.TODO()
+
+		// Create a scheme and register the rbac/v1 API
+		scheme = runtime.NewScheme()
+		Expect(v1.AddToScheme(scheme)).To(Succeed())
+
+		// Initialize the fake client
+		var err error
+		fakeClient, err = testing.GetFakeClient(scheme)
+		Expect(err).ToNot(HaveOccurred())
+
+		// Define subjects, roleRef, labels, and annotations
+		subjects = []v1.Subject{
+			{
+				Kind:      "User",
+				Name:      "test-user",
+				Namespace: "test-namespace",
+			},
+		}
+		roleRef = resources.NewClusterRoleRef("test-role")
+		labels = map[string]string{"key1": "value1"}
+		annotations = map[string]string{"annotation1": "value1"}
+
+		// Create a cluster role binding mutator
+		mutator = resources.NewClusterRoleBindingMutator("test-clusterrolebinding", subjects, roleRef, labels, annotations)
+	})
+
+	It("should create an empty cluster role binding with correct metadata", func() {
+		clusterRoleBinding := mutator.Empty()
+
+		Expect(clusterRoleBinding.Name).To(Equal("test-clusterrolebinding"))
+		Expect(clusterRoleBinding.APIVersion).To(Equal("rbac.authorization.k8s.io/v1"))
+		Expect(clusterRoleBinding.Kind).To(Equal("ClusterRoleBinding"))
+	})
+
+	It("should apply subjects and roleRef using Mutate", func() {
+		clusterRoleBinding := mutator.Empty()
+
+		// Apply the mutator's Mutate method
+		Expect(mutator.Mutate(clusterRoleBinding)).To(Succeed())
+
+		// Verify that the subjects and roleRef are applied
+		Expect(clusterRoleBinding.Subjects).To(Equal(subjects))
+		Expect(clusterRoleBinding.RoleRef).To(Equal(roleRef))
+	})
+
+	It("should create and retrieve the cluster role binding using the fake client", func() {
+		clusterRoleBinding := mutator.Empty()
+		Expect(mutator.Mutate(clusterRoleBinding)).To(Succeed())
+
+		// Create the cluster role binding in the fake client
+		Expect(fakeClient.Create(ctx, clusterRoleBinding)).To(Succeed())
+
+		// Retrieve the cluster role binding from the fake client and verify it
+		retrievedClusterRoleBinding := &v1.ClusterRoleBinding{}
+		Expect(fakeClient.Get(ctx, client.ObjectKey{Name: "test-clusterrolebinding"}, retrievedClusterRoleBinding)).To(Succeed())
+		Expect(retrievedClusterRoleBinding).To(Equal(clusterRoleBinding))
+	})
+})