forked from kubernetes-retired/multi-tenancy
/
tenantnamespace_controller.go
341 lines (310 loc) · 11.1 KB
/
tenantnamespace_controller.go
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/*
Copyright 2019 The Kubernetes Authors.
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 tenantnamespace
import (
"context"
"fmt"
tenancyv1alpha1 "github.com/kubernetes-sigs/multi-tenancy/tenant/pkg/apis/tenancy/v1alpha1"
tenantutil "github.com/kubernetes-sigs/multi-tenancy/tenant/pkg/util"
corev1 "k8s.io/api/core/v1"
rbacv1 "k8s.io/api/rbac/v1"
"k8s.io/apimachinery/pkg/api/errors"
metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
"k8s.io/apimachinery/pkg/runtime"
"k8s.io/apimachinery/pkg/types"
"k8s.io/client-go/util/retry"
"sigs.k8s.io/controller-runtime/pkg/client"
"sigs.k8s.io/controller-runtime/pkg/controller"
"sigs.k8s.io/controller-runtime/pkg/handler"
"sigs.k8s.io/controller-runtime/pkg/manager"
"sigs.k8s.io/controller-runtime/pkg/reconcile"
logf "sigs.k8s.io/controller-runtime/pkg/runtime/log"
"sigs.k8s.io/controller-runtime/pkg/source"
)
var log = logf.Log.WithName("controller")
const (
// TenantAdminNamespaceAnnotation is the key for tenantAdminNamespace annotation
TenantAdminNamespaceAnnotation = "x-k8s.io/tenantAdminNamespace"
TenantNamespaceFinalizer = "tenantnamespace.finalizer.x-k8s.io"
)
// Add creates a new TenantNamespace Controller and adds it to the Manager with default RBAC. The Manager will set fields on the Controller
// and Start it when the Manager is Started.
func Add(mgr manager.Manager) error {
return AddManager(mgr, NewReconciler(mgr))
}
// NewReconciler returns a new reconcile.Reconciler
func NewReconciler(mgr manager.Manager) reconcile.Reconciler {
return &ReconcileTenantNamespace{Client: mgr.GetClient(), scheme: mgr.GetScheme()}
}
// AddManager adds a new Controller to mgr with r as the reconcile.Reconciler
func AddManager(mgr manager.Manager, r reconcile.Reconciler) error {
// Create a new controller
c, err := controller.New("tenantnamespace-controller", mgr, controller.Options{Reconciler: r})
if err != nil {
return err
}
// Watch for changes to TenantNamespace
err = c.Watch(&source.Kind{Type: &tenancyv1alpha1.TenantNamespace{}}, &handler.EnqueueRequestForObject{})
if err != nil {
return err
}
// Watch for changes to namespaces
err = c.Watch(&source.Kind{Type: &corev1.Namespace{}}, &enqueueTenantNamespace{})
if err != nil {
return err
}
return nil
}
var _ reconcile.Reconciler = &ReconcileTenantNamespace{}
// ReconcileTenantNamespace reconciles a TenantNamespace object
type ReconcileTenantNamespace struct {
client.Client
scheme *runtime.Scheme
}
// Add a ownerReference and tenant admin namespace annotation to input namespace
func (r *ReconcileTenantNamespace) updateNamespace(ns *corev1.Namespace, tenantAdminNamespaceName *string, ownerRef *metav1.OwnerReference) error {
nsClone := ns.DeepCopy()
err := retry.RetryOnConflict(retry.DefaultBackoff, func() error {
nsClone.OwnerReferences = append(nsClone.OwnerReferences, *ownerRef)
if nsClone.Annotations == nil {
nsClone.Annotations = make(map[string]string)
}
nsClone.Annotations[TenantAdminNamespaceAnnotation] = *tenantAdminNamespaceName
updateErr := r.Update(context.TODO(), nsClone)
if updateErr == nil {
return nil
}
key := types.NamespacedName{
Name: nsClone.Name,
}
if err := r.Get(context.TODO(), key, nsClone); err != nil {
log.Info("Fail to fetch namespace on update failure", "namespace", nsClone.Name)
}
return updateErr
})
return err
}
func findTenant(adminNsName string, tList *tenancyv1alpha1.TenantList) (string, bool) {
// Find the tenant that owns the adminNs
requireNamespacePrefix := false
var tenantName string
for _, each := range tList.Items {
if each.Spec.TenantAdminNamespaceName == adminNsName {
requireNamespacePrefix = each.Spec.RequireNamespacePrefix
tenantName = each.Name
break
}
}
return tenantName, requireNamespacePrefix
}
// Reconcile reads that state of the cluster for a TenantNamespace object and makes changes based on the state read
// and what is in the TenantNamespace.Spec
// Automatically generate RBAC rules to allow the Controller to read and write Deployments
// +kubebuilder:rbac:groups=core,resources=namespaces,verbs=get;list;watch;create
// +kubebuilder:rbac:groups=tenancy.x-k8s.io,resources=tenantnamespaces,verbs=get;list;watch;create;update;patch;delete
// +kubebuilder:rbac:groups=tenancy.x-k8s.io,resources=tenantnamespaces/status,verbs=get;update;patch
func (r *ReconcileTenantNamespace) Reconcile(request reconcile.Request) (reconcile.Result, error) {
// Fetch the TenantNamespace instance
instance := &tenancyv1alpha1.TenantNamespace{}
err := r.Get(context.TODO(), request.NamespacedName, instance)
if err != nil {
if errors.IsNotFound(err) {
// Object not found, return. Created objects are automatically garbage collected.
// For additional cleanup logic use finalizers.
return reconcile.Result{}, nil
}
// Error reading the object - requeue the request.
return reconcile.Result{}, err
}
// Fetch namespace list
nsList := &corev1.NamespaceList{}
err = r.List(context.TODO(), nsList, &client.ListOptions{})
if err != nil {
return reconcile.Result{}, err
}
// Fetch tenant list
tenantList := &tenancyv1alpha1.TenantList{}
err = r.List(context.TODO(), tenantList, &client.ListOptions{})
if err != nil {
return reconcile.Result{}, err
}
tenantName, requireNamespacePrefix := findTenant(instance.Namespace, tenantList)
// Handle tenantNamespace CR deletion
if instance.DeletionTimestamp != nil {
if tenantName != "" {
// Remove namespace from tenant clusterrole
if err = r.updateTenantClusterRole(tenantName, instance.Status.OwnedNamespace, false); err != nil {
return reconcile.Result{}, err
}
}
instanceClone := instance.DeepCopy()
if containsString(instanceClone.Finalizers, TenantNamespaceFinalizer) {
instanceClone.Finalizers = removeString(instanceClone.Finalizers, TenantNamespaceFinalizer)
}
err = r.Update(context.TODO(), instanceClone)
return reconcile.Result{}, err
} else if tenantName == "" {
return reconcile.Result{}, fmt.Errorf("TenantNamespace CR %v does not belong to any tenant", instance)
}
// In case namespace already exists
tenantNsName := tenantutil.GetTenantNamespaceName(requireNamespacePrefix, instance)
expectedOwnerRef := metav1.OwnerReference{
APIVersion: tenancyv1alpha1.SchemeGroupVersion.String(),
Kind: "TenantNamespace",
Name: instance.Name,
UID: instance.UID,
}
found := false
for _, each := range nsList.Items {
if each.Name == tenantNsName {
found = true
// Check OwnerReference
isOwner := false
for _, ownerRef := range each.OwnerReferences {
if ownerRef == expectedOwnerRef {
isOwner = true
break
} else if ownerRef.APIVersion == expectedOwnerRef.APIVersion && ownerRef.Kind == expectedOwnerRef.Kind {
// The namespace is owned by another TenantNamespace CR, fail the reconcile
err = fmt.Errorf("Namespace %v is owned by another %v TenantNamespace CR", each.Name, ownerRef)
return reconcile.Result{}, err
}
}
if !isOwner {
log.Info("Namespace has been created without TenantNamespace owner", "namespace", each.Name)
// Obtain namespace ownership by setting ownerReference, and add annotation
if err = r.updateNamespace(&each, &instance.Namespace, &expectedOwnerRef); err != nil {
return reconcile.Result{}, err
}
}
break
}
}
// In case a new namespace needs to be created
if !found {
tenantNs := &corev1.Namespace{
TypeMeta: metav1.TypeMeta{
APIVersion: corev1.SchemeGroupVersion.String(),
Kind: "Namespace",
},
ObjectMeta: metav1.ObjectMeta{
Name: tenantNsName,
Annotations: map[string]string{
TenantAdminNamespaceAnnotation: instance.Namespace,
},
OwnerReferences: []metav1.OwnerReference{expectedOwnerRef},
},
}
if err = r.Client.Create(context.TODO(), tenantNs); err != nil {
return reconcile.Result{}, err
}
}
// Update status
instanceClone := instance.DeepCopy()
err = retry.RetryOnConflict(retry.DefaultBackoff, func() error {
if !containsString(instanceClone.Finalizers, TenantNamespaceFinalizer) {
instanceClone.Finalizers = append(instanceClone.Finalizers, TenantNamespaceFinalizer)
}
instanceClone.Status.OwnedNamespace = tenantNsName
updateErr := r.Update(context.TODO(), instanceClone)
if updateErr == nil {
return nil
}
if err := r.Get(context.TODO(), types.NamespacedName{Name: instance.Name, Namespace: instance.Namespace}, instanceClone); err != nil {
log.Info("Fail to fetch tenantNamespace CR on update", "tenantNamespace", instance.Name)
}
return updateErr
})
if err != nil {
return reconcile.Result{}, err
}
// Add namespace to tenant clusterrule to allow tenant admins to access it.
err = r.updateTenantClusterRole(tenantName, tenantNsName, true)
return reconcile.Result{}, err
}
// This method updates tenant clusterrule to add or remove the tenant namespace.
func (r *ReconcileTenantNamespace) updateTenantClusterRole(tenantName, tenantNsName string, add bool) error {
var err error
cr := &rbacv1.ClusterRole{}
if err = r.Get(context.TODO(), types.NamespacedName{Name: fmt.Sprintf("%s-tenant-admin-role", tenantName)}, cr); err != nil {
if errors.IsNotFound(err) {
return nil
} else {
return err
}
}
cr = cr.DeepCopy()
foundNsRule := false
needUpdate := add
for i, each := range cr.Rules {
for _, resource := range each.Resources {
if resource == "namespaces" {
foundNsRule = true
break
}
}
if foundNsRule {
idx := 0
for ; idx < len(each.ResourceNames); idx++ {
if each.ResourceNames[idx] == tenantNsName {
needUpdate = !add
break
}
}
if needUpdate {
if add {
cr.Rules[i].ResourceNames = append(cr.Rules[i].ResourceNames, tenantNsName)
} else {
cr.Rules[i].ResourceNames = append(cr.Rules[i].ResourceNames[:idx], cr.Rules[i].ResourceNames[idx+1:]...)
}
}
break
}
}
if !foundNsRule {
return fmt.Errorf("Cluster Role %s-tenant-admin-role does not have rules for namespaces.", tenantName)
}
if needUpdate {
crClone := cr.DeepCopy()
err = retry.RetryOnConflict(retry.DefaultBackoff, func() error {
crClone.Rules = cr.Rules
updateErr := r.Update(context.TODO(), crClone)
if updateErr == nil {
return nil
}
if err := r.Get(context.TODO(), types.NamespacedName{Name: crClone.Name}, crClone); err != nil {
log.Info("Fail to fetch clusterrole on update", "clusterrole", crClone.Name)
}
return updateErr
})
}
return err
}
// Helper functions to check and remove string from a slice of strings.
func containsString(slice []string, s string) bool {
for _, item := range slice {
if item == s {
return true
}
}
return false
}
func removeString(slice []string, s string) (result []string) {
for _, item := range slice {
if item == s {
continue
}
result = append(result, item)
}
return
}