refactor(k8s): namespace core logic (#12142)

Co-authored-by: testA113 <aliharriss1995@gmail.com>
Co-authored-by: Anthony Lapenna <anthony.lapenna@portainer.io>
Co-authored-by: James Carppe <85850129+jamescarppe@users.noreply.github.com>
Co-authored-by: Ali <83188384+testA113@users.noreply.github.com>

api/kubernetes/cli/cluster_role.go

@@ -0,0 +1,43 @@
+package cli
+
+import (
+	"context"
+	"fmt"
+
+	models "github.com/portainer/portainer/api/http/models/kubernetes"
+	rbacv1 "k8s.io/api/rbac/v1"
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+)
+
+// GetClusterRoles gets all the clusterRoles for at the cluster level in a k8s endpoint.
+// It returns a list of K8sClusterRole objects.
+func (kcl *KubeClient) GetClusterRoles() ([]models.K8sClusterRole, error) {
+	if kcl.IsKubeAdmin {
+		return kcl.fetchClusterRoles()
+	}
+
+	return []models.K8sClusterRole{}, fmt.Errorf("non-admin users are not allowed to access cluster roles")
+}
+
+// fetchClusterRoles returns a list of all Roles in the specified namespace.
+func (kcl *KubeClient) fetchClusterRoles() ([]models.K8sClusterRole, error) {
+	clusterRoles, err := kcl.cli.RbacV1().ClusterRoles().List(context.TODO(), metav1.ListOptions{})
+	if err != nil {
+		return nil, err
+	}
+
+	results := make([]models.K8sClusterRole, 0)
+	for _, clusterRole := range clusterRoles.Items {
+		results = append(results, parseClusterRole(clusterRole))
+	}
+
+	return results, nil
+}
+
+// parseClusterRole converts a rbacv1.ClusterRole object to a models.K8sClusterRole object.
+func parseClusterRole(clusterRole rbacv1.ClusterRole) models.K8sClusterRole {
+	return models.K8sClusterRole{
+		Name:         clusterRole.Name,
+		CreationDate: clusterRole.CreationTimestamp.Time,
+	}
+}