mapper.go

/*
Copyright 2020 The Kubermatic Kubernetes Platform contributors.

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

    http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
*/

package rbac

import (
	"fmt"
	"strings"

	kubermaticv1 "github.com/kubermatic/kubermatic/api/pkg/crd/kubermatic/v1"

	rbacv1 "k8s.io/api/rbac/v1"
	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
)

const (
	// OwnerGroupNamePrefix represents owners group prefix
	OwnerGroupNamePrefix = "owners"

	// EditorGroupNamePrefix represents editors group prefix
	EditorGroupNamePrefix = "editors"

	// ViewerGroupNamePrefix represents viewers group prefix
	ViewerGroupNamePrefix = "viewers"

	// RBACResourcesNamePrefix represents kubermatic group prefix
	RBACResourcesNamePrefix = "kubermatic"
)

const (
	saSecretsNamespaceName = "kubermatic"
)

// AllGroupsPrefixes holds a list of groups with prefixes that we will generate RBAC Roles/Binding for.
//
// Note:
// adding a new group also requires updating generateVerbsForNamedResource method.
// the actual names of groups are different see generateActualGroupNameFor function
var AllGroupsPrefixes = []string{
	OwnerGroupNamePrefix,
	EditorGroupNamePrefix,
	ViewerGroupNamePrefix,
}

// GenerateActualGroupNameFor generates a group name for the given project and group prefix.
func GenerateActualGroupNameFor(projectName, groupName string) string {
	return fmt.Sprintf("%s-%s", groupName, projectName)
}

// ExtractGroupPrefix extracts only group prefix from the given group name
func ExtractGroupPrefix(groupName string) string {
	ret := strings.Split(groupName, "-")
	if len(ret) > 0 {
		return ret[0]
	}
	return groupName
}

func generateRBACRoleNameForNamedResource(kind, resourceName, groupName string) string {
	return fmt.Sprintf("%s:%s-%s:%s", RBACResourcesNamePrefix, strings.ToLower(kind), resourceName, groupName)
}

func generateRBACRoleNameForResources(resourceName, groupName string) string {
	groupPrefix := ExtractGroupPrefix(groupName)
	return fmt.Sprintf("%s:%s:%s", RBACResourcesNamePrefix, resourceName, groupPrefix)
}

func generateRBACRoleNameForClusterNamespaceResource(kind, groupName string) string {
	return fmt.Sprintf("%s:%s:%s", RBACResourcesNamePrefix, strings.ToLower(kind), ExtractGroupPrefix(groupName))
}

// generateClusterRBACRoleNamedResource generates ClusterRole for a named resource.
// named resources have its rules set to a resource with the given name for example:
// the following rule allows reading a ConfigMap named “my-config”
//  rules:
//   - apiGroups: [""]
//   resources: ["configmaps"]
//   resourceNames: ["my-config"]
//   verbs: ["get"]
//
// Note that for some kinds we don't want to generate ClusterRole in that case a nil cluster resource will be returned without an error
func generateClusterRBACRoleNamedResource(kind, groupName, policyResource, policyAPIGroups, policyResourceName string, oRef metav1.OwnerReference) (*rbacv1.ClusterRole, error) {
	verbs, err := generateVerbsForNamedResource(groupName, kind)
	if err != nil {
		return nil, err
	}
	if len(verbs) == 0 {
		return nil, nil
	}
	role := &rbacv1.ClusterRole{
		ObjectMeta: metav1.ObjectMeta{
			Name:            generateRBACRoleNameForNamedResource(kind, policyResourceName, groupName),
			OwnerReferences: []metav1.OwnerReference{oRef},
		},
		Rules: []rbacv1.PolicyRule{
			{
				APIGroups:     []string{policyAPIGroups},
				Resources:     []string{policyResource},
				ResourceNames: []string{policyResourceName},
				Verbs:         verbs,
			},
		},
	}
	return role, nil
}

// generateClusterRBACRoleBindingNamedResource generates ClusterRoleBiding for the given group
// that will be bound to the corresponding ClusterRole
func generateClusterRBACRoleBindingNamedResource(kind, resourceName, groupName string, oRef metav1.OwnerReference) *rbacv1.ClusterRoleBinding {
	binding := &rbacv1.ClusterRoleBinding{
		ObjectMeta: metav1.ObjectMeta{
			Name:            generateRBACRoleNameForNamedResource(kind, resourceName, groupName),
			OwnerReferences: []metav1.OwnerReference{oRef},
		},
		Subjects: []rbacv1.Subject{
			{
				APIGroup: rbacv1.GroupName,
				Kind:     "Group",
				Name:     groupName,
			},
		},
		RoleRef: rbacv1.RoleRef{
			APIGroup: rbacv1.GroupName,
			Kind:     "ClusterRole",
			Name:     generateRBACRoleNameForNamedResource(kind, resourceName, groupName),
		},
	}
	return binding
}

// generateClusterRBACRoleForResource generates ClusterRole for the given resource
// Note that for some groups we don't want to generate ClusterRole in that case a nil will be returned
func generateClusterRBACRoleForResource(groupName, policyResource, policyAPIGroups, kind string) (*rbacv1.ClusterRole, error) {
	verbs, err := generateVerbsForResource(groupName, kind)
	if err != nil {
		return nil, err
	}
	if len(verbs) == 0 {
		return nil, nil
	}
	role := &rbacv1.ClusterRole{
		ObjectMeta: metav1.ObjectMeta{
			Name: generateRBACRoleNameForResources(policyResource, groupName),
		},
		Rules: []rbacv1.PolicyRule{
			{
				APIGroups: []string{policyAPIGroups},
				Resources: []string{policyResource},
				Verbs:     verbs,
			},
		},
	}
	return role, nil
}

func generateClusterRBACRoleBindingForResource(resourceName, groupName string) *rbacv1.ClusterRoleBinding {
	binding := &rbacv1.ClusterRoleBinding{
		ObjectMeta: metav1.ObjectMeta{
			Name: generateRBACRoleNameForResources(resourceName, groupName),
		},
		Subjects: []rbacv1.Subject{
			{
				APIGroup: rbacv1.GroupName,
				Kind:     "Group",
				Name:     groupName,
			},
		},
		RoleRef: rbacv1.RoleRef{
			APIGroup: rbacv1.GroupName,
			Kind:     "ClusterRole",
			Name:     generateRBACRoleNameForResources(resourceName, groupName),
		},
	}
	return binding
}

func generateRBACRoleBindingForResource(resourceName, groupName, namespace string) *rbacv1.RoleBinding {
	binding := &rbacv1.RoleBinding{
		ObjectMeta: metav1.ObjectMeta{
			Name:      generateRBACRoleNameForResources(resourceName, groupName),
			Namespace: namespace,
		},
		Subjects: []rbacv1.Subject{
			{
				APIGroup: rbacv1.GroupName,
				Kind:     "Group",
				Name:     groupName,
			},
		},
		RoleRef: rbacv1.RoleRef{
			APIGroup: rbacv1.GroupName,
			Kind:     "Role",
			Name:     generateRBACRoleNameForResources(resourceName, groupName),
		},
	}
	return binding
}

// generateRBACRoleForResource generates Role for the given resource in the given namespace
// Note that for some groups we don't want to generate Role in that case a nil will be returned
func generateRBACRoleForResource(groupName, policyResource, policyAPIGroups, kind string, namespace string) (*rbacv1.Role, error) {
	verbs, err := generateVerbsForNamespacedResource(groupName, kind, namespace)
	if err != nil {
		return nil, err
	}
	if len(verbs) == 0 {
		return nil, nil
	}
	role := &rbacv1.Role{
		ObjectMeta: metav1.ObjectMeta{
			Name:      generateRBACRoleNameForResources(policyResource, groupName),
			Namespace: namespace,
		},
		Rules: []rbacv1.PolicyRule{
			{
				APIGroups: []string{policyAPIGroups},
				Resources: []string{policyResource},
				Verbs:     verbs,
			},
		},
	}
	return role, nil
}

// generateRBACRoleNamedResource generates Role for a named resource.
// named resources have its rules set to a resource with the given name for example:
// the following rule allows reading a ConfigMap named “my-config”
//  rules:
//   - apiGroups: [""]
//   resources: ["configmaps"]
//   resourceNames: ["my-config"]
//   verbs: ["get"]
//
// Note that for some kinds we don't want to generate Role in that case a nil cluster resource will be returned without an error
func generateRBACRoleNamedResource(kind, groupName, policyResource, policyAPIGroups, policyResourceName string, namespace string, oRef metav1.OwnerReference) (*rbacv1.Role, error) {
	verbs, err := generateVerbsForNamedResourceInNamespace(groupName, kind, namespace)
	if err != nil {
		return nil, err
	}
	if len(verbs) == 0 {
		return nil, nil
	}
	role := &rbacv1.Role{
		ObjectMeta: metav1.ObjectMeta{
			Name:            generateRBACRoleNameForNamedResource(kind, policyResourceName, groupName),
			OwnerReferences: []metav1.OwnerReference{oRef},
			Namespace:       namespace,
		},
		Rules: []rbacv1.PolicyRule{
			{
				APIGroups:     []string{policyAPIGroups},
				Resources:     []string{policyResource},
				ResourceNames: []string{policyResourceName},
				Verbs:         verbs,
			},
		},
	}
	return role, nil
}

// generateRBACRoleBindingNamedResource generates RoleBiding for the given group
// that will be bound to the corresponding Role
func generateRBACRoleBindingNamedResource(kind, resourceName, groupName, namespace string, oRef metav1.OwnerReference) *rbacv1.RoleBinding {
	binding := &rbacv1.RoleBinding{
		ObjectMeta: metav1.ObjectMeta{
			Name:            generateRBACRoleNameForNamedResource(kind, resourceName, groupName),
			OwnerReferences: []metav1.OwnerReference{oRef},
			Namespace:       namespace,
		},
		Subjects: []rbacv1.Subject{
			{
				APIGroup: rbacv1.GroupName,
				Kind:     "Group",
				Name:     groupName,
			},
		},
		RoleRef: rbacv1.RoleRef{
			APIGroup: rbacv1.GroupName,
			Kind:     "Role",
			Name:     generateRBACRoleNameForNamedResource(kind, resourceName, groupName),
		},
	}
	return binding
}

// generateRBACRoleForClusterNamespaceResource generates per-cluster Role for the given cluster in the cluster namespace
// Note that for some groups we don't want to generate Role in that case a nil will be returned
func generateRBACRoleForClusterNamespaceResource(cluster *kubermaticv1.Cluster, groupName, policyResource, policyAPIGroups, kind string) (*rbacv1.Role, error) {
	verbs, err := generateVerbsForClusterNamespaceResource(cluster, groupName, kind)
	if err != nil {
		return nil, err
	}
	if len(verbs) == 0 {
		return nil, nil
	}
	role := &rbacv1.Role{
		ObjectMeta: metav1.ObjectMeta{
			Name:      generateRBACRoleNameForClusterNamespaceResource(kind, groupName),
			Namespace: cluster.Status.NamespaceName,
		},
		Rules: []rbacv1.PolicyRule{
			{
				APIGroups: []string{policyAPIGroups},
				Resources: []string{policyResource},
				Verbs:     verbs,
			},
		},
	}
	return role, nil
}

// generateRBACRoleBindingForClusterNamespaceResource generates per-cluster RoleBinding for the given cluster in the cluster namespace
// Note that for some groups we don't want to generate RoleBinding in that case a nil will be returned
func generateRBACRoleBindingForClusterNamespaceResource(cluster *kubermaticv1.Cluster, groupName, kind string) *rbacv1.RoleBinding {
	binding := &rbacv1.RoleBinding{
		ObjectMeta: metav1.ObjectMeta{
			Name:      generateRBACRoleNameForClusterNamespaceResource(kind, groupName),
			Namespace: cluster.Status.NamespaceName,
		},
		Subjects: []rbacv1.Subject{
			{
				APIGroup: rbacv1.GroupName,
				Kind:     "Group",
				Name:     groupName,
			},
		},
		RoleRef: rbacv1.RoleRef{
			APIGroup: rbacv1.GroupName,
			Kind:     "Role",
			Name:     generateRBACRoleNameForClusterNamespaceResource(kind, groupName),
		},
	}
	return binding
}

// generateVerbsForNamedResource generates a set of verbs for a named resource
// for example a "cluster" named "beefy-john"
func generateVerbsForNamedResource(groupName, resourceKind string) ([]string, error) {
	// verbs for owners
	//
	// owners of a named resource
	if strings.HasPrefix(groupName, OwnerGroupNamePrefix) {
		return []string{"get", "update", "delete"}, nil
	}

	// verbs for editors
	//
	// editors of a project
	// special case - editors are not allowed to delete a project
	if strings.HasPrefix(groupName, EditorGroupNamePrefix) && resourceKind == kubermaticv1.ProjectKindName {
		return []string{"get", "update"}, nil
	}
	// special case - editors are not allowed to interact with members of a project (UserProjectBinding)
	if strings.HasPrefix(groupName, EditorGroupNamePrefix) && resourceKind == kubermaticv1.UserProjectBindingKind {
		return nil, nil
	}
	// special case - editors are not allowed to interact with service accounts (User)
	if strings.HasPrefix(groupName, EditorGroupNamePrefix) && resourceKind == kubermaticv1.UserKindName {
		return nil, nil
	}

	// editors of a named resource
	if strings.HasPrefix(groupName, EditorGroupNamePrefix) {
		return []string{"get", "update", "delete"}, nil
	}

	// verbs for editors
	//
	// viewers of a named resource
	// special case - viewers are not allowed to interact with members of a project (UserProjectBinding)
	if strings.HasPrefix(groupName, ViewerGroupNamePrefix) && resourceKind == kubermaticv1.UserProjectBindingKind {
		return nil, nil
	}
	// special case - viewers are not allowed to interact with service accounts (User)
	if strings.HasPrefix(groupName, ViewerGroupNamePrefix) && resourceKind == kubermaticv1.UserKindName {
		return nil, nil
	}
	if strings.HasPrefix(groupName, ViewerGroupNamePrefix) {
		return []string{"get"}, nil
	}

	// unknown group passed
	return nil, fmt.Errorf("unable to generate verbs, unknown group name passed in = %s", groupName)
}

// generateVerbsForResource generates verbs for a resource for example "cluster"
// to make it even more concrete, if there is "create" verb returned for owners group, that means that the owners can create "cluster" resources.
func generateVerbsForResource(groupName, resourceKind string) ([]string, error) {
	// special case - only the owners of a project can manipulate members
	//
	if strings.HasPrefix(groupName, OwnerGroupNamePrefix) && resourceKind == kubermaticv1.UserProjectBindingKind {
		return []string{"create"}, nil
	} else if resourceKind == kubermaticv1.UserProjectBindingKind {
		return nil, nil
	}

	// special case - only the owners of a project can create service account (aka. users)
	//
	if strings.HasPrefix(groupName, OwnerGroupNamePrefix) && resourceKind == kubermaticv1.UserKindName {
		return []string{"create"}, nil
	} else if resourceKind == kubermaticv1.UserKindName {
		return nil, nil
	}

	// verbs for owners and editors
	//
	// owners and editors can create resources
	if strings.HasPrefix(groupName, OwnerGroupNamePrefix) || strings.HasPrefix(groupName, EditorGroupNamePrefix) {
		return []string{"create"}, nil
	}

	// verbs for readers
	//
	// viewers cannot create resources
	if strings.HasPrefix(groupName, ViewerGroupNamePrefix) {
		return nil, nil
	}

	// unknown group passed
	return nil, fmt.Errorf("unable to generate verbs, unknown group name passed in = %s", groupName)
}

func generateVerbsForNamespacedResource(groupName, resourceKind, namespace string) ([]string, error) {
	// special case - only the owners of a project can create secrets in "saSecretsNamespaceName" namespace
	//
	if namespace == saSecretsNamespaceName {
		secretV1Kind := "Secret"
		if strings.HasPrefix(groupName, OwnerGroupNamePrefix) && resourceKind == secretV1Kind {
			return []string{"create"}, nil
		} else if resourceKind == secretV1Kind {
			return nil, nil
		}
	}

	// unknown group passed
	return nil, fmt.Errorf("unable to generate verbs, unknown group name passed in = %s, namespace = %s", groupName, namespace)
}

// generateVerbsForNamedResourceInNamespace generates a set of verbs for a named resource in a given namespace
// for example a "cluster" named "beefy-john"
func generateVerbsForNamedResourceInNamespace(groupName, resourceKind, namespace string) ([]string, error) {
	// special case - only the owners of a project can manipulate secrets in "ssaSecretsNamespaceNam" namespace
	//
	if namespace == saSecretsNamespaceName {
		secretV1Kind := "Secret"
		if strings.HasPrefix(groupName, OwnerGroupNamePrefix) && resourceKind == secretV1Kind {
			return []string{"get", "update", "delete"}, nil
		} else if resourceKind == secretV1Kind {
			return nil, nil
		}
	}

	// unknown group passed
	return nil, fmt.Errorf("unable to generate verbs for group = %s, kind = %s, namespace = %s", groupName, resourceKind, namespace)
}

func generateVerbsForClusterNamespaceResource(cluster *kubermaticv1.Cluster, groupName, kind string) ([]string, error) {
	if strings.HasPrefix(groupName, ViewerGroupNamePrefix) && kind == kubermaticv1.AddonKindName {
		return []string{"get", "list"}, nil
	}

	if strings.HasPrefix(groupName, OwnerGroupNamePrefix) || strings.HasPrefix(groupName, EditorGroupNamePrefix) {
		return []string{"get", "list", "create", "update", "delete"}, nil
	}

	// unknown group passed
	return nil, fmt.Errorf("unable to generate verbs for cluster namespace resource cluster = %s, group = %s, kind = %s", cluster.Name, groupName, kind)
}