/
update.go
95 lines (81 loc) · 3.37 KB
/
update.go
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// Copyright (c) 2019 SAP SE or an SAP affiliate company. All rights reserved. This file is licensed under the Apache Software License, v. 2 except as noted otherwise in the LICENSE file
//
// 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 controller
import (
"context"
"reflect"
"time"
apierrors "k8s.io/apimachinery/pkg/api/errors"
"k8s.io/apimachinery/pkg/util/wait"
"sigs.k8s.io/controller-runtime/pkg/client"
)
// TryUpdate tries to apply the given transformation function onto the given object, and to update it afterwards.
// It retries the update with an exponential backoff.
func TryUpdate(ctx context.Context, backoff wait.Backoff, c client.Client, obj client.Object, transform func() error) error {
return tryUpdate(ctx, backoff, c, obj, c.Update, transform)
}
// TryUpdateStatus tries to apply the given transformation function onto the given object, and to update its
// status afterwards. It retries the status update with an exponential backoff.
func TryUpdateStatus(ctx context.Context, backoff wait.Backoff, c client.Client, obj client.Object, transform func() error) error {
return tryUpdate(ctx, backoff, c, obj, c.Status().Update, transform)
}
func tryUpdate(ctx context.Context, backoff wait.Backoff, c client.Client, obj client.Object, updateFunc func(context.Context, client.Object, ...client.UpdateOption) error, transform func() error) error {
resetCopy := obj.DeepCopyObject()
return exponentialBackoff(ctx, backoff, func() (bool, error) {
if err := c.Get(ctx, client.ObjectKeyFromObject(obj), obj); err != nil {
return false, err
}
beforeTransform := obj.DeepCopyObject()
if err := transform(); err != nil {
return false, err
}
if reflect.DeepEqual(obj, beforeTransform) {
return true, nil
}
if err := updateFunc(ctx, obj); err != nil {
if apierrors.IsConflict(err) {
// In case of a conflict we are resetting the obj to its original version, as it was
// passed to the function, to ensure that, on the next iteration the
// equality check of the obj recieved from the server and the object after
// its transformation would be valid. Otherwise the obj would be with mutated
// fields in result of the transform function from previous iteration.
reflect.ValueOf(obj).Elem().Set(reflect.ValueOf(resetCopy).Elem())
return false, nil
}
return false, err
}
return true, nil
})
}
func exponentialBackoff(ctx context.Context, backoff wait.Backoff, condition wait.ConditionFunc) error {
duration := backoff.Duration
for i := 0; i < backoff.Steps; i++ {
if ok, err := condition(); err != nil || ok {
return err
}
select {
case <-ctx.Done():
return ctx.Err()
default:
adjusted := duration
if backoff.Jitter > 0.0 {
adjusted = wait.Jitter(duration, backoff.Jitter)
}
time.Sleep(adjusted)
duration = time.Duration(float64(duration) * backoff.Factor)
}
i++
}
return wait.ErrWaitTimeout
}