Repository: yonahd/kor (go)

Issue:
feature: Discover unused RoleBindings
**Is your feature request related to a problem?**
RoleBindings can be created while referencing **non-existing** users/groups/ServiceAccounts on one hand or Roles/ClusterRoles on the other hand.

Go through all existing RoleBindings and verify if they are applied to existing subjects and roles.
Utilize `ShowReason` flag to indicate that the reason the RoleBinding was considered unused was because it referenced an unused subject or role.

__**NOTE:**__ Since a RoleBinding can include multiple subject references, discovering a single non-existing subject (one of several existing ones) might indicate the RoleBinding as unused while it actually is, in that case, it shouldn't be considered as unused.

<details>
<summary>Examples</summary>

In the attached example, we could see a RoleBinding with references to both users: `alice` & `bob`.
1. Assuming both users `alice` & `bob` does not exist, the Role is not applied to them, hence the RoleBinding will be considered as **UNUSED**.
2. Assuming both users `alice` & `bob` exist, but the Role does not exist, it is not applied to them, hence the RoleBinding will be considered as **UNUSED**.
3. Assuming user `alice` does exist and the Role is applied to it, even while `bob` does not exist - the RoleBinding will be considered as **USED**.

```
apiVersion: rbac.authorization.k8s.io/v1
kind: RoleBinding
metadata:
  name: read-pods
  namespace: default
subjects:
- kind: User
  name: alice
  apiGroup: rbac.authorization.k8s.io
- kind: User
  name: bob
  apiGroup: rbac.authorization.k8s.io
roleRef:
  kind: Role 
  name: pod-reader 
  apiGroup: rbac.authorization.k8s.io
```

</details>


**Describe the solution you'd like**
```console
$ kor rolebindings
Unused RoleBindings:
+---+----------------+----------------------------------------------+-----------------------------+
| # | NAMESPACE      |   RESOURCE NAME    |                         REASON                        |
+---+----------------+----------------------------------------------+-----------------------------+
| 1 | example-ns-1   | example-rb-1       | RoleBinding references a non-existing ServiceAccount  |  
| 2 | example-ns-2   | example-rb-2       | RoleBinding references a non-existing ClusterRole     |
+---+----------------+----------------------------------------------+-----------------------------+
```
**Feature checklist**
- [ ] `pkg/kor/rolebindings.go`
- [ ] `pkg/kor/rolebindings_test.go`
- [ ] `pkg/kor/create_test_resources.go`
- [ ] `pkg/kor/all.go`
- [ ] `pkg/kor/delete.go`
- [ ] `pkg/kor/multi.go`
- [ ] `cmd/kor/rolebindings.go`
- [ ] `charts/kor/templates/role.yaml`
- [ ] `README.md`

Pull request description:
Feat: Discover unused RoleBindings
<!-- Please read [CONTRIBUTING.md](CONTRIBUTING.md) for additional information on contributing to this repository! -->

<!--
  !!!! README !!!! Please fill this out.

  Please follow conventional commit naming conventions:

  https://www.conventionalcommits.org/en/v1.0.0/#summary
-->

<!-- A short description of what your PR does and what it solves. -->

## What this PR does / why we need it?
This is a partial PR as I ran into challenges validating whether User or Group subjects exist. As you likely know, Kubernetes doesn’t store user or group information in its resources. I could use your input—am I missing something? How can we reliably verify the existence of a user or group?

Currently, a RoleBinding is considered unused if it references a non-existent Role, ClusterRole, or if none of its ServiceAccount subjects are valid.

We might consider merging this PR as is and opening a separate issue to address User and Group validation—I'll leave that decision to you.
## PR Checklist

- [ ] This PR adds K8s exceptions (false positives)
- [x] This PR adds new code
- [x] This PR includes tests for new/existing code
- [ ] This PR adds docs
<!-- - [ ] This PR does something else -->

## GitHub Issue

Closes #334

<!-- Notes that may be helpful for anyone reviewing this PR -->

## Notes for your reviewers
![rolebinding-feature](https://github.com/user-attachments/assets/2cb59d21-5235-487c-93a2-d867ac6f6366)

Patch:
diff --git a/README.md b/README.md
index 46e1412..31aec8e 100644
--- a/README.md
+++ b/README.md
@@ -31,6 +31,7 @@ Kor is a tool to discover unused Kubernetes resources. Currently, Kor can identi
 - DaemonSets
 - StorageClasses
 - NetworkPolicies
+- RoleBindings
 
 ![Kor Screenshot](/images/show_reason_screenshot.png)
 
@@ -110,6 +111,7 @@ Kor provides various subcommands to identify and list unused resources. The avai
 - `statefulset` - Gets unused StatefulSets for the specified namespace or all namespaces.
 - `role` - Gets unused Roles for the specified namespace or all namespaces.
 - `clusterrole` - Gets unused ClusterRoles for the specified namespace or all namespaces (namespace refers to RoleBinding).
+- `rolebinding` - Gets unused RoleBindings for the specified namespace or all namespaces.
 - `hpa` - Gets unused HPAs for the specified namespace or all namespaces.
 - `pod` - Gets unused Pods for the specified namespace or all namespaces.
 - `pvc` - Gets unused PVCs for the specified namespace or all namespaces.
@@ -172,6 +174,7 @@ kor [subcommand] --help
 | StatefulSets    | Statefulsets with no Replicas                                                                                                                                                                                                     |                                                                                                                                                                       |
 | Roles           | Roles not used in roleBinding                                                                                                                                                                                                     |                                                                                                                                                                       |
 | ClusterRoles    | ClusterRoles not used in roleBinding or clusterRoleBinding<br/>ClusterRoles not used in ClusterRole aggregation                                                                                                                                                                        |                                                                                                                                                                       |
+| RoleBindings    | RoleBindings referencing invalid Role, ClusterRole, or ServiceAccounts                                                                                                                                           |                                                                                                                                                                       |
 | PVCs            | PVCs not used in Pods                                                                                                                                                                                                             |                                                                                                                                                                       |
 | Ingresses       | Ingresses not pointing at any Service                                                                                                                                                                                             |                                                                                                                                                                       |
 | Hpas            | HPAs not used in Deployments<br/> HPAs not used in StatefulSets                                                                                                                                                                   |                                                                                                                                                                       |
diff --git a/cmd/kor/rolebindings.go b/cmd/kor/rolebindings.go
new file mode 100644
index 0000000..5b47145
--- /dev/null
+++ b/cmd/kor/rolebindings.go
@@ -0,0 +1,31 @@
+package kor
+
+import (
+	"fmt"
+
+	"github.com/spf13/cobra"
+
+	"github.com/yonahd/kor/pkg/kor"
+	"github.com/yonahd/kor/pkg/utils"
+)
+
+var roleBindingCmd = &cobra.Command{
+	Use:     "rolebinding",
+	Aliases: []string{"rolebindings"},
+	Short:   "Gets unused role bindings",
+	Args:    cobra.ExactArgs(0),
+	Run: func(cmd *cobra.Command, args []string) {
+		clientset := kor.GetKubeClient(kubeconfig)
+
+		if response, err := kor.GetUnusedRoleBindings(filterOptions, clientset, outputFormat, opts); err != nil {
+			fmt.Println(err)
+		} else {
+			utils.PrintLogo(outputFormat)
+			fmt.Println(response)
+		}
+	},
+}
+
+func init() {
+	rootCmd.AddCommand(roleBindingCmd)
+}
diff --git a/pkg/kor/all.go b/pkg/kor/all.go
index 37af741..ffaad22 100644
--- a/pkg/kor/all.go
+++ b/pkg/kor/all.go
@@ -264,6 +264,19 @@ func getUnusedNetworkPolicies(clientset kubernetes.Interface, namespace string,
 	return namespaceNetpolDiff
 }
 
+func getUnusedRoleBindings(clientset kubernetes.Interface, namespace string, filterOpts *filters.Options) ResourceDiff {
+	roleBindingDiff, err := processNamespaceRoleBindings(clientset, namespace, filterOpts)
+	if err != nil {
+		fmt.Fprintf(os.Stderr, "Failed to get %s namespace %s: %v\n", "RoleBindings", namespace, err)
+	}
+
+	namespaceRoleBindingDiff := ResourceDiff{
+		"RoleBinding",
+		roleBindingDiff,
+	}
+	return namespaceRoleBindingDiff
+}
+
 func GetUnusedAllNamespaced(filterOpts *filters.Options, clientset kubernetes.Interface, outputFormat string, opts common.Opts) (string, error) {
 	resources := make(map[string]map[string][]ResourceInfo)
 	for _, namespace := range filterOpts.Namespaces(clientset) {
@@ -286,6 +299,7 @@ func GetUnusedAllNamespaced(filterOpts *filters.Options, clientset kubernetes.In
 			resources[namespace]["ReplicaSet"] = getUnusedReplicaSets(clientset, namespace, filterOpts).diff
 			resources[namespace]["DaemonSet"] = getUnusedDaemonSets(clientset, namespace, filterOpts).diff
 			resources[namespace]["NetworkPolicy"] = getUnusedNetworkPolicies(clientset, namespace, filterOpts).diff
+			resources[namespace]["RoleBinding"] = getUnusedRoleBindings(clientset, namespace, filterOpts).diff
 		case "resource":
 			appendResources(resources, "ConfigMap", namespace, getUnusedCMs(clientset, namespace, filterOpts).diff)
 			appendResources(resources, "Service", namespace, getUnusedSVCs(clientset, namespace, filterOpts).diff)
@@ -303,6 +317,7 @@ func GetUnusedAllNamespaced(filterOpts *filters.Options, clientset kubernetes.In
 			appendResources(resources, "ReplicaSet", namespace, getUnusedReplicaSets(clientset, namespace, filterOpts).diff)
 			appendResources(resources, "DaemonSet", namespace, getUnusedDaemonSets(clientset, namespace, filterOpts).diff)
 			appendResources(resources, "NetworkPolicy", namespace, getUnusedNetworkPolicies(clientset, namespace, filterOpts).diff)
+			appendResources(resources, "RoleBinding", namespace, getUnusedRoleBindings(clientset, namespace, filterOpts).diff)
 		}
 	}
 
diff --git a/pkg/kor/delete.go b/pkg/kor/delete.go
index a1e6f68..7efcec3 100644
--- a/pkg/kor/delete.go
+++ b/pkg/kor/delete.go
@@ -81,6 +81,9 @@ func DeleteResourceCmd() map[string]func(clientset kubernetes.Interface, namespa
 		"NetworkPolicy": func(clientset kubernetes.Interface, namespace, name string) error {
 			return clientset.NetworkingV1().NetworkPolicies(namespace).Delete(context.TODO(), name, metav1.DeleteOptions{})
 		},
+		"RoleBinding": func(clientset kubernetes.Interface, namespace, name string) error {
+			return clientset.RbacV1().RoleBindings(namespace).Delete(context.TODO(), name, metav1.DeleteOptions{})
+		},
 	}
 
 	return deleteResourceApiMap
@@ -170,6 +173,8 @@ func updateResource(clientset kubernetes.Interface, namespace, resourceType stri
 		return clientset.StorageV1().StorageClasses().Update(context.TODO(), resource.(*storagev1.StorageClass), metav1.UpdateOptions{})
 	case "NetworkPolicy":
 		return clientset.NetworkingV1().NetworkPolicies(namespace).Update(context.TODO(), resource.(*networkingv1.NetworkPolicy), metav1.UpdateOptions{})
+	case "RoleBinding":
+		return clientset.RbacV1().RoleBindings(namespace).Update(context.TODO(), resource.(*rbacv1.RoleBinding), metav1.UpdateOptions{})
 	}
 	return nil, fmt.Errorf("resource type '%s' is not supported", resourceType)
 }
@@ -214,6 +219,8 @@ func getResource(clientset kubernetes.Interface, namespace, resourceType, resour
 		return clientset.StorageV1().StorageClasses().Get(context.TODO(), resourceName, metav1.GetOptions{})
 	case "NetworkPolicy":
 		return clientset.NetworkingV1().NetworkPolicies(namespace).Get(context.TODO(), resourceName, metav1.GetOptions{})
+	case "RoleBinding":
+		return clientset.RbacV1().RoleBindings(namespace).Get(context.TODO(), resourceName, metav1.GetOptions{})
 	}
 	return nil, fmt.Errorf("resource type '%s' is not supported", resourceType)
 }
diff --git a/pkg/kor/exceptions/rolebindings/rolebindings.json b/pkg/kor/exceptions/rolebindings/rolebindings.json
new file mode 100644
index 0000000..df1b861
--- /dev/null
+++ b/pkg/kor/exceptions/rolebindings/rolebindings.json
@@ -0,0 +1,34 @@
+{
+    "exceptionRoleBindings": [
+        {
+            "Namespace": "kube-public",
+            "ResourceName": "kubeadm:bootstrap-signer-clusterinfo"
+        },
+        {
+            "Namespace": "kube-public",
+            "ResourceName": "system:controller:bootstrap-signer"
+        },
+        {
+            "Namespace": "kube-system",
+            "ResourceName": "kube-proxy"
+        },
+        {
+            "Namespace": "kube-system",
+            "ResourceName": "kubeadm:kubelet-config"
+        },
+        {
+            "Namespace": "kube-system",
+            "ResourceName": "kubeadm:nodes-kubeadm-config"
+        },
+        {
+            "Namespace": "kube-system",
+            "ResourceName": "system::*",
+            "MatchRegex": true
+        },
+        {
+            "Namespace": "kube-system",
+            "ResourceName": "system:controller:*",
+            "MatchRegex": true
+        }
+    ]
+}
diff --git a/pkg/kor/kor.go b/pkg/kor/kor.go
index 2be6a72..be6968c 100644
--- a/pkg/kor/kor.go
+++ b/pkg/kor/kor.go
@@ -38,6 +38,7 @@ type Config struct {
 	ExceptionStorageClasses  []ExceptionResource `json:"exceptionStorageClasses"`
 	ExceptionJobs            []ExceptionResource `json:"exceptionJobs"`
 	ExceptionPdbs            []ExceptionResource `json:"exceptionPdbs"`
+	ExceptionRoleBindings    []ExceptionResource `json:"exceptionRoleBindings"`
 	// Add other configurations if needed
 }
 
@@ -190,3 +191,17 @@ func resourceInfoContains(slice []ResourceInfo, item string) bool {
 	}
 	return false
 }
+
+// Convert a slice of names into a map for fast lookup
+func convertNamesToPresenseMap(names []string, _ []string, err error) (map[string]bool, error) {
+	if err != nil {
+		return nil, err
+	}
+
+	namesMap := make(map[string]bool)
+	for _, n := range names {
+		namesMap[n] = true
+	}
+
+	return namesMap, nil
+}
diff --git a/pkg/kor/multi.go b/pkg/kor/multi.go
index 914ca6d..ef2dfd9 100644
--- a/pkg/kor/multi.go
+++ b/pkg/kor/multi.go
@@ -89,6 +89,8 @@ func retrieveNamespaceDiffs(clientset kubernetes.Interface, namespace string, re
 			diffResult = getUnusedDaemonSets(clientset, namespace, filterOpts)
 		case "netpol", "networkpolicy", "networkpolicies":
 			diffResult = getUnusedNetworkPolicies(clientset, namespace, filterOpts)
+		case "rolebinding", "rolebindings":
+			diffResult = getUnusedNetworkPolicies(clientset, namespace, filterOpts)
 		default:
 			fmt.Printf("resource type %q is not supported\n", resource)
 		}
diff --git a/pkg/kor/rolebindings.go b/pkg/kor/rolebindings.go
new file mode 100644
index 0000000..a9b1329
--- /dev/null
+++ b/pkg/kor/rolebindings.go
@@ -0,0 +1,158 @@
+package kor
+
+import (
+	"bytes"
+	"context"
+	_ "embed"
+	"encoding/json"
+	"fmt"
+	"os"
+
+	v1 "k8s.io/api/rbac/v1"
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+	"k8s.io/client-go/kubernetes"
+
+	"github.com/yonahd/kor/pkg/common"
+	"github.com/yonahd/kor/pkg/filters"
+)
+
+//go:embed exceptions/rolebindings/rolebindings.json
+var roleBindingsConfig []byte
+
+// Filter out subjects base on Kind, can be later used for User and Group
+func filterSubjects(subjects []v1.Subject, kind string) []v1.Subject {
+	var serviceAccountSubjects []v1.Subject
+	for _, subject := range subjects {
+		if subject.Kind == kind {
+			serviceAccountSubjects = append(serviceAccountSubjects, subject)
+		}
+	}
+	return serviceAccountSubjects
+}
+
+// Check if any valid service accounts exist in the RoleBinding
+func isUsingValidServiceAccount(serviceAccounts []v1.Subject, serviceAccountNames map[string]bool) bool {
+	for _, sa := range serviceAccounts {
+		if serviceAccountNames[sa.Name] {
+			return true
+		}
+	}
+	return false
+}
+
+func validateRoleReference(rb v1.RoleBinding, roleNames, clusterRoleNames map[string]bool) *ResourceInfo {
+	if rb.RoleRef.Kind == "Role" && !roleNames[rb.RoleRef.Name] {
+		return &ResourceInfo{Name: rb.Name, Reason: "RoleBinding references a non-existing Role"}
+	}
+
+	if rb.RoleRef.Kind == "ClusterRole" && !clusterRoleNames[rb.RoleRef.Name] {
+		return &ResourceInfo{Name: rb.Name, Reason: "RoleBinding references a non-existing ClusterRole"}
+	}
+
+	return nil
+}
+
+func processNamespaceRoleBindings(clientset kubernetes.Interface, namespace string, filterOpts *filters.Options) ([]ResourceInfo, error) {
+	roleBindingsList, err := clientset.RbacV1().RoleBindings(namespace).List(context.TODO(), metav1.ListOptions{LabelSelector: filterOpts.IncludeLabels})
+	if err != nil {
+		return nil, err
+	}
+
+	roleNames, err := convertNamesToPresenseMap(retrieveRoleNames(clientset, namespace, filterOpts))
+	if err != nil {
+		return nil, err
+	}
+
+	clusterRoleNames, err := convertNamesToPresenseMap(retrieveClusterRoleNames(clientset, filterOpts))
+	if err != nil {
+		return nil, err
+	}
+
+	serviceAccountNames, err := convertNamesToPresenseMap(retrieveServiceAccountNames(clientset, namespace, filterOpts))
+	if err != nil {
+		return nil, err
+	}
+
+	config, err := unmarshalConfig(roleBindingsConfig)
+	if err != nil {
+		return nil, err
+	}
+
+	var unusedRoleBindingNames []ResourceInfo
+
+	for _, rb := range roleBindingsList.Items {
+		if pass, _ := filter.SetObject(&rb).Run(filterOpts); pass {
+			continue
+		}
+
+		if exceptionFound, err := isResourceException(rb.Name, rb.Namespace, config.ExceptionRoleBindings); err != nil {
+			return nil, err
+		} else if exceptionFound {
+			continue
+		}
+
+		roleReferenceIssue := validateRoleReference(rb, roleNames, clusterRoleNames)
+		if roleReferenceIssue != nil {
+			unusedRoleBindingNames = append(unusedRoleBindingNames, *roleReferenceIssue)
+			continue
+		}
+
+		serviceAccountSubjects := filterSubjects(rb.Subjects, "ServiceAccount")
+
+		// If other kinds (Users/Groups) are used, we assume they exists for now
+		if len(serviceAccountSubjects) != len(rb.Subjects) {
+			continue
+		}
+
+		// Check if RoleBinding uses a valid service account
+		if !isUsingValidServiceAccount(serviceAccountSubjects, serviceAccountNames) {
+			unusedRoleBindingNames = append(unusedRoleBindingNames, ResourceInfo{Name: rb.Name, Reason: "RoleBinding references a non-existing ServiceAccount"})
+		}
+	}
+
+	return unusedRoleBindingNames, nil
+}
+
+func GetUnusedRoleBindings(filterOpts *filters.Options, clientset kubernetes.Interface, outputFormat string, opts common.Opts) (string, error) {
+	resources := make(map[string]map[string][]ResourceInfo)
+	for _, namespace := range filterOpts.Namespaces(clientset) {
+		diff, err := processNamespaceRoleBindings(clientset, namespace, filterOpts)
+		if err != nil {
+			fmt.Fprintf(os.Stderr, "Failed to process namespace %s: %v\n", namespace, err)
+			continue
+		}
+
+		if opts.DeleteFlag {
+			if diff, err = DeleteResource(diff, clientset, namespace, "RoleBinding", opts.NoInteractive); err != nil {
+				fmt.Fprintf(os.Stderr, "Failed to delete RoleBinding %s in namespace %s: %v\n", diff, namespace, err)
+			}
+		}
+
+		switch opts.GroupBy {
+		case "namespace":
+			resources[namespace] = make(map[string][]ResourceInfo)
+			resources[namespace]["RoleBinding"] = diff
+		case "resource":
+			appendResources(resources, "RoleBinding", namespace, diff)
+		}
+	}
+
+	var outputBuffer bytes.Buffer
+	var jsonResponse []byte
+	switch outputFormat {
+	case "table":
+		outputBuffer = FormatOutput(resources, opts)
+	case "json", "yaml":
+		var err error
+		if jsonResponse, err = json.MarshalIndent(resources, "", " "); err != nil {
+			return "", err
+		}
+	}
+
+	unusedRoleBindings, err := unusedResourceFormatter(outputFormat, outputBuffer, opts, jsonResponse)
+	if err != nil {
+		fmt.Printf("err: %v\n", err)
+	}
+
+	return unusedRoleBindings, nil
+}


Test patch:
diff --git a/pkg/kor/rolebindings_test.go b/pkg/kor/rolebindings_test.go
new file mode 100644
index 0000000..a865a7a
--- /dev/null
+++ b/pkg/kor/rolebindings_test.go
@@ -0,0 +1,163 @@
+package kor
+
+import (
+	"context"
+	"encoding/json"
+	"reflect"
+	"testing"
+
+	appsv1 "k8s.io/api/apps/v1"
+	corev1 "k8s.io/api/core/v1"
+	rbacv1 "k8s.io/api/rbac/v1"
+	v1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+	"k8s.io/apimachinery/pkg/runtime"
+	"k8s.io/client-go/kubernetes/fake"
+	"k8s.io/client-go/kubernetes/scheme"
+
+	"github.com/yonahd/kor/pkg/common"
+	"github.com/yonahd/kor/pkg/filters"
+)
+
+func createTestRoleBindings(t *testing.T) *fake.Clientset {
+	clientset := fake.NewSimpleClientset()
+
+	_, err := clientset.CoreV1().Namespaces().Create(context.TODO(), &corev1.Namespace{
+		ObjectMeta: v1.ObjectMeta{Name: testNamespace},
+	}, v1.CreateOptions{})
+
+	if err != nil {
+		t.Fatalf("Error creating namespace %s: %v", testNamespace, err)
+	}
+
+	rb1 := CreateTestRoleBinding(
+		testNamespace,
+		"test-rb1",
+		"sa1",
+		&rbacv1.RoleRef{
+			Kind: "Role",
+			Name: "non-exists-role",
+		})
+	_, err = clientset.RbacV1().RoleBindings(testNamespace).Create(context.TODO(), rb1, v1.CreateOptions{})
+	if err != nil {
+		t.Fatalf("Error creating fake %s: %v", "RoleBinding: rb1", err)
+	}
+
+	rb2 := CreateTestRoleBinding(
+		testNamespace,
+		"test-rb2",
+		"sa2",
+		&rbacv1.RoleRef{
+			Kind: "ClusterRole",
+			Name: "non-existing-cluster-rule",
+		})
+	_, err = clientset.RbacV1().RoleBindings(testNamespace).Create(context.TODO(), rb2, v1.CreateOptions{})
+	if err != nil {
+		t.Fatalf("Error creating fake %s: %v", "RoleBinding: rb2", err)
+	}
+
+	testRole := CreateTestRole(testNamespace, "existing-role", AppLabels)
+	_, err = clientset.RbacV1().Roles(testNamespace).Create(context.TODO(), testRole, v1.CreateOptions{})
+	if err != nil {
+		t.Fatalf("Error creating fake %s: %v", "Role", err)
+	}
+
+	rb3 := CreateTestRoleBinding(
+		testNamespace,
+		"test-rb3",
+		"non-existing-service-account",
+		&rbacv1.RoleRef{
+			Kind: "Role",
+			Name: "existing-role",
+		})
+	_, err = clientset.RbacV1().RoleBindings(testNamespace).Create(context.TODO(), rb3, v1.CreateOptions{})
+	if err != nil {
+		t.Fatalf("Error creating fake %s: %v", "RoleBinding: rb3", err)
+	}
+
+	rb4 := CreateTestRoleBinding(
+		testNamespace,
+		"test-rb4",
+		"non-existing-service-account",
+		&rbacv1.RoleRef{
+			Kind: "Role",
+			Name: "existing-role",
+		})
+
+	sa4 := CreateTestServiceAccount(testNamespace, "existing-service-account", AppLabels)
+	_, err = clientset.CoreV1().ServiceAccounts(testNamespace).Create(context.TODO(), sa4, v1.CreateOptions{})
+	if err != nil {
+		t.Fatalf("Error creating fake %s: %v", "ServiceAccount", err)
+	}
+
+	rbacSubject := CreateTestRbacSubject(testNamespace, "existing-service-account")
+	rb4.Subjects = append(rb4.Subjects, *rbacSubject)
+	_, err = clientset.RbacV1().RoleBindings(testNamespace).Create(context.TODO(), rb4, v1.CreateOptions{})
+	if err != nil {
+		t.Fatalf("Error creating fake %s: %v", "RoleBinding: rb4", err)
+	}
+	return clientset
+}
+
+func TestProcessNamespaceRoleBindings(t *testing.T) {
+	clientset := createTestRoleBindings(t)
+
+	unusedRoleBindings, err := processNamespaceRoleBindings(clientset, testNamespace, &filters.Options{})
+	if err != nil {
+		t.Errorf("Expected no error, got %v", err)
+	}
+
+	expectedRoleBindingNames := []string{"test-rb1", "test-rb2", "test-rb3"}
+
+	if len(unusedRoleBindings) != len(expectedRoleBindingNames) {
+		t.Errorf("Expected %d unused role bindings, got %d", len(expectedRoleBindingNames), len(unusedRoleBindings))
+	}
+
+	for i, rb := range unusedRoleBindings {
+		if rb.Name != expectedRoleBindingNames[i] {
+			t.Errorf("Expected %s, got %s", expectedRoleBindingNames[i], rb.Name)
+		}
+	}
+
+}
+
+func TestGetUnusedRoleBindingStructured(t *testing.T) {
+	clientset := createTestRoleBindings(t)
+
+	opts := common.Opts{
+		WebhookURL:    "",
+		Channel:       "",
+		Token:         "",
+		DeleteFlag:    false,
+		NoInteractive: true,
+		GroupBy:       "namespace",
+	}
+
+	output, err := GetUnusedRoleBindings(&filters.Options{}, clientset, "json", opts)
+	if err != nil {
+		t.Fatalf("Error calling GetUnusedRoleBindingStructured: %v", err)
+	}
+
+	expectedOutput := map[string]map[string][]string{
+		testNamespace: {
+			"RoleBinding": {
+				"test-rb1",
+				"test-rb2",
+				"test-rb3",
+			},
+		},
+	}
+
+	var actualOutput map[string]map[string][]string
+	if err := json.Unmarshal([]byte(output), &actualOutput); err != nil {
+		t.Fatalf("Error unmarshaling actual output: %v", err)
+	}
+
+	if !reflect.DeepEqual(expectedOutput, actualOutput) {
+		t.Errorf("Expected output does not match actual output")
+	}
+}
+
+func init() {
+	scheme.Scheme = runtime.NewScheme()
+	_ = appsv1.AddToScheme(scheme.Scheme)
+}