Files
capsule/controllers/tenant/resourcequotas.go
2021-08-07 21:37:48 +02:00

252 lines
9.5 KiB
Go

package tenant
import (
"context"
"fmt"
"strconv"
"golang.org/x/sync/errgroup"
corev1 "k8s.io/api/core/v1"
"k8s.io/apimachinery/pkg/api/resource"
metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
"k8s.io/apimachinery/pkg/labels"
"k8s.io/apimachinery/pkg/selection"
"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/controllerutil"
capsulev1beta1 "github.com/clastix/capsule/api/v1beta1"
)
// When the Resource Budget assigned to a Tenant is Tenant-scoped we have to rely on the ResourceQuota resources to
// represent the resource quota for the single Tenant rather than the single Namespace,
// so abusing of this API although its Namespaced scope.
//
// Since a Namespace could take-up all the available resource quota, the Namespace ResourceQuota will be a 1:1 mapping
// to the Tenant one: in first time Capsule is going to sum all the analogous ResourceQuota resources on other Tenant
// namespaces to check if the Tenant quota has been exceeded or not, reusing the native Kubernetes policy putting the
// .Status.Used value as the .Hard value.
// This will trigger following reconciliations but that's ok: the mutateFn will re-use the same business logic, letting
// the mutateFn along with the CreateOrUpdate to don't perform the update since resources are identical.
//
// In case of Namespace-scoped Resource Budget, we're just replicating the resources across all registered Namespaces.
func (r *Manager) syncResourceQuotas(tenant *capsulev1beta1.Tenant) (err error) {
// getting ResourceQuota labels for the mutateFn
var tenantLabel, typeLabel string
if tenantLabel, err = capsulev1beta1.GetTypeLabel(&capsulev1beta1.Tenant{}); err != nil {
return err
}
if typeLabel, err = capsulev1beta1.GetTypeLabel(&corev1.ResourceQuota{}); err != nil {
return err
}
if tenant.Spec.ResourceQuota.Scope == capsulev1beta1.ResourceQuotaScopeTenant {
group := new(errgroup.Group)
for i, q := range tenant.Spec.ResourceQuota.Items {
index := i
resourceQuota := q
group.Go(func() (scopeErr error) {
// Calculating the Resource Budget at Tenant scope just if this is put in place.
// Requirement to list ResourceQuota of the current Tenant
var tntRequirement *labels.Requirement
if tntRequirement, scopeErr = labels.NewRequirement(tenantLabel, selection.Equals, []string{tenant.Name}); scopeErr != nil {
r.Log.Error(scopeErr, "Cannot build ResourceQuota Tenant requirement")
}
// Requirement to list ResourceQuota for the current index
var indexRequirement *labels.Requirement
if indexRequirement, scopeErr = labels.NewRequirement(typeLabel, selection.Equals, []string{strconv.Itoa(index)}); scopeErr != nil {
r.Log.Error(scopeErr, "Cannot build ResourceQuota index requirement")
}
// Listing all the ResourceQuota according to the said requirements.
// These are required since Capsule is going to sum all the used quota to
// sum them and get the Tenant one.
list := &corev1.ResourceQuotaList{}
if scopeErr = r.List(context.TODO(), list, &client.ListOptions{LabelSelector: labels.NewSelector().Add(*tntRequirement).Add(*indexRequirement)}); scopeErr != nil {
r.Log.Error(scopeErr, "Cannot list ResourceQuota", "tenantFilter", tntRequirement.String(), "indexFilter", indexRequirement.String())
return
}
// Iterating over all the options declared for the ResourceQuota,
// summing all the used quota across different Namespaces to determinate
// if we're hitting a Hard quota at Tenant level.
// For this case, we're going to block the Quota setting the Hard as the
// used one.
for name, hardQuota := range resourceQuota.Hard {
r.Log.Info("Desired hard " + name.String() + " quota is " + hardQuota.String())
// Getting the whole usage across all the Tenant Namespaces
var quantity resource.Quantity
for _, item := range list.Items {
quantity.Add(item.Status.Used[name])
}
r.Log.Info("Computed " + name.String() + " quota for the whole Tenant is " + quantity.String())
switch quantity.Cmp(resourceQuota.Hard[name]) {
case 0:
// The Tenant is matching exactly the Quota:
// falling through next case since we have to block further
// resource allocations.
fallthrough
case 1:
// The Tenant is OverQuota:
// updating all the related ResourceQuota with the current
// used Quota to block further creations.
for item := range list.Items {
if _, ok := list.Items[item].Status.Used[name]; ok {
list.Items[item].Spec.Hard[name] = list.Items[item].Status.Used[name]
} else {
um := make(map[corev1.ResourceName]resource.Quantity)
um[name] = resource.Quantity{}
list.Items[item].Spec.Hard = um
}
}
default:
// The Tenant is respecting the Hard quota:
// restoring the default one for all the elements,
// also for the reconciled one.
for item := range list.Items {
if list.Items[item].Spec.Hard == nil {
list.Items[item].Spec.Hard = map[corev1.ResourceName]resource.Quantity{}
}
list.Items[item].Spec.Hard[name] = resourceQuota.Hard[name]
}
}
if scopeErr = r.resourceQuotasUpdate(name, quantity, resourceQuota.Hard[name], list.Items...); scopeErr != nil {
r.Log.Error(scopeErr, "cannot proceed with outer ResourceQuota")
return
}
}
return
})
}
// Waiting the update of all ResourceQuotas
if err = group.Wait(); err != nil {
return
}
}
// getting requested ResourceQuota keys
keys := make([]string, 0, len(tenant.Spec.ResourceQuota.Items))
for i := range tenant.Spec.ResourceQuota.Items {
keys = append(keys, strconv.Itoa(i))
}
group := new(errgroup.Group)
for _, ns := range tenant.Status.Namespaces {
namespace := ns
group.Go(func() error {
return r.syncResourceQuota(tenant, namespace, keys)
})
}
return group.Wait()
}
func (r *Manager) syncResourceQuota(tenant *capsulev1beta1.Tenant, namespace string, keys []string) (err error) {
// getting ResourceQuota labels for the mutateFn
var tenantLabel, typeLabel string
if tenantLabel, err = capsulev1beta1.GetTypeLabel(&capsulev1beta1.Tenant{}); err != nil {
return err
}
if typeLabel, err = capsulev1beta1.GetTypeLabel(&corev1.ResourceQuota{}); err != nil {
return err
}
// Pruning resource of non-requested resources
if err = r.pruningResources(namespace, keys, &corev1.ResourceQuota{}); err != nil {
return err
}
for index, resQuota := range tenant.Spec.ResourceQuota.Items {
target := &corev1.ResourceQuota{
ObjectMeta: metav1.ObjectMeta{
Name: fmt.Sprintf("capsule-%s-%d", tenant.Name, index),
Namespace: namespace,
},
}
var res controllerutil.OperationResult
err = retry.RetryOnConflict(retry.DefaultBackoff, func() (retryErr error) {
res, retryErr = controllerutil.CreateOrUpdate(context.TODO(), r.Client, target, func() (err error) {
target.SetLabels(map[string]string{
tenantLabel: tenant.Name,
typeLabel: strconv.Itoa(index),
})
target.Spec.Scopes = resQuota.Scopes
target.Spec.ScopeSelector = resQuota.ScopeSelector
// In case of Namespace scope for the ResourceQuota we can easily apply the bare specification
if tenant.Spec.ResourceQuota.Scope == capsulev1beta1.ResourceQuotaScopeNamespace {
target.Spec.Hard = resQuota.Hard
}
return controllerutil.SetControllerReference(tenant, target, r.Scheme)
})
return retryErr
})
r.emitEvent(tenant, target.GetNamespace(), res, fmt.Sprintf("Ensuring ResourceQuota %s", target.GetName()), err)
r.Log.Info("Resource Quota sync result: "+string(res), "name", target.Name, "namespace", target.Namespace)
if err != nil {
return
}
}
return nil
}
// Serial ResourceQuota processing is expensive: using Go routines we can speed it up.
// In case of multiple errors these are logged properly, returning a generic error since we have to repush back the
// reconciliation loop.
func (r *Manager) resourceQuotasUpdate(resourceName corev1.ResourceName, actual, limit resource.Quantity, list ...corev1.ResourceQuota) (err error) {
group := new(errgroup.Group)
for _, item := range list {
rq := item
group.Go(func() (err error) {
found := &corev1.ResourceQuota{}
if err = r.Get(context.TODO(), types.NamespacedName{Namespace: rq.Namespace, Name: rq.Name}, found); err != nil {
return
}
return retry.RetryOnConflict(retry.DefaultBackoff, func() (retryErr error) {
_, retryErr = controllerutil.CreateOrUpdate(context.TODO(), r.Client, found, func() error {
// Ensuring annotation map is there to avoid uninitialized map error and
// assigning the overall usage
if found.Annotations == nil {
found.Annotations = make(map[string]string)
}
found.Labels = rq.Labels
found.Annotations[capsulev1beta1.UsedQuotaFor(resourceName)] = actual.String()
found.Annotations[capsulev1beta1.HardQuotaFor(resourceName)] = limit.String()
// Updating the Resource according to the actual.Cmp result
found.Spec.Hard = rq.Spec.Hard
return nil
})
return retryErr
})
})
}
if err = group.Wait(); err != nil {
// We had an error and we mark the whole transaction as failed
// to process it another time according to the Tenant controller back-off factor.
r.Log.Error(err, "Cannot update outer ResourceQuotas", "resourceName", resourceName.String())
err = fmt.Errorf("update of outer ResourceQuota items has failed: %s", err.Error())
}
return err
}