Files
unkin-agent 9da206dc7c Implement autobackup-operator controllers, tests, CI and packaging
PVCs and CloudNativePG Clusters need S3 buckets and backup schedules
provisioned consistently. This operator watches the
backups.unkin.net/{schedule,destination} annotations on those objects and
provisions everything needed to back them up, with no new CRDs.

- Add a PVC controller that provisions cephrgw ObjectStoreUser/Bucket/BucketAccess,
  auto-generates a restic repo-password Secret and creates a k8up Schedule scoped
  to the PVC via spec.backup.volumes[].persistentVolumeClaim.claimName.
- Add a CNPG Cluster controller that provisions the same bucket stack, idempotently
  patches spec.backup.barmanObjectStore (leaving a user-set destinationPath alone
  with a Warning event) and creates a ScheduledBackup.
- Resolve destinations through a ConfigMap lookup table; requeue until the
  BucketAccess is Ready before creating schedule resources; own-reference created
  resources and retain bucket data by default.
- Add schedule-mapping helpers (k8up 5-field/shortcut pass-through, CNPG 6-field
  seconds-first) and deterministic, length-bounded name derivation.
- Add unit tests (schedule mapping, name derivation, destination resolution) and
  envtest controller tests for both paths, wiring the external CRDs into envtest.
- Add kubebuilder-generated RBAC, a Dockerfile (distroless/nonroot), Woodpecker
  lint/test/build pipelines and a tag-triggered image push to the artifactapi
  docker-internal registry, plus a version-bump Makefile and deploy manifests.
2026-08-14 00:08:37 +10:00

84 lines
2.2 KiB
Go

/*
Copyright 2023 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 synctrack
import (
"sync"
"sync/atomic"
)
// Lazy defers the computation of `Evaluate` to when it is necessary. It is
// possible that Evaluate will be called in parallel from multiple goroutines.
type Lazy[T any] struct {
Evaluate func() (T, error)
cache atomic.Pointer[cacheEntry[T]]
}
type cacheEntry[T any] struct {
eval func() (T, error)
lock sync.RWMutex
result *T
}
func (e *cacheEntry[T]) get() (T, error) {
if cur := func() *T {
e.lock.RLock()
defer e.lock.RUnlock()
return e.result
}(); cur != nil {
return *cur, nil
}
e.lock.Lock()
defer e.lock.Unlock()
if e.result != nil {
return *e.result, nil
}
r, err := e.eval()
if err == nil {
e.result = &r
}
return r, err
}
func (z *Lazy[T]) newCacheEntry() *cacheEntry[T] {
return &cacheEntry[T]{eval: z.Evaluate}
}
// Notify should be called when something has changed necessitating a new call
// to Evaluate.
func (z *Lazy[T]) Notify() { z.cache.Swap(z.newCacheEntry()) }
// Get should be called to get the current result of a call to Evaluate. If the
// current cached value is stale (due to a call to Notify), then Evaluate will
// be called synchronously. If subsequent calls to Get happen (without another
// Notify), they will all wait for the same return value.
//
// Error returns are not cached and will cause multiple calls to evaluate!
func (z *Lazy[T]) Get() (T, error) {
e := z.cache.Load()
if e == nil {
// Since we don't force a constructor, nil is a possible value.
// If multiple Gets race to set this, the swap makes sure only
// one wins.
z.cache.CompareAndSwap(nil, z.newCacheEntry())
e = z.cache.Load()
}
return e.get()
}