Approach summary: build a controller using client-go informers + workqueue that watches ExternalBucket CRD; reconcile ensures an S3 bucket exists/has desired policy and updates CR status. Make it idempotent, scale-safe, and robust to transient failures.Key components:- Informer for ExternalBucket (SharedIndexInformer)- Rate-limiting workqueue (workqueue.RateLimitingInterface)- Reconcile worker loop (pop key, sync, handle errors)- S3 client wrapper with idempotent operations (CreateBucketIfNotExists, PutBucketPolicy, HeadBucket)- Status updates on CR (conditions: Ready, Error)- RBAC rules: allow get/list/watch/update/status on ExternalBucket, secrets, and core resourcesPseudo-code critical paths:go
// onAdd/onUpdate/onDelete -> enqueue(key)
func worker() {
for processNext() {}
}
func processNext() bool {
key, quit := queue.Get()
if quit { return false }
defer queue.Done(key)
if err := syncHandler(key.(string)); err != nil {
queue.AddRateLimited(key)
logger.Error(err)
} else {
queue.Forget(key)
}
return true
}
func syncHandler(key string) error {
ns, name := splitKey(key)
eb := lister.ExternalBuckets(ns).Get(name) // may return notFound -> cleanup
if eb == nil { return nil } // resource deleted -> ensure S3 bucket removed if finalizer present
// idempotent reconcile:
desired := eb.Spec.BucketName
// safe read: HeadBucket
exists, err := s3.HeadBucket(desired)
if err != nil && !IsNotFound(err) { return transientErr(err) }
if !exists {
if err := s3.CreateBucketIfNotExists(desired, eb.Spec.Region); err != nil { setStatusError(...); return err }
}
if err := s3.EnsureBucketPolicy(desired, eb.Spec.Policy); err != nil { setStatusError(...); return err }
// update status to Ready
if !statusReady(eb) { updateStatusReady(eb) }
return nil
}
