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cephrgw-operator/README.md
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Support adopting existing radosgw buckets and users
The operator previously assumed it created every user and bucket it managed:
reconciling an existing resource could overwrite its user attributes or wipe its
bucket policy, and deleting a CRD always deleted the underlying RGW object (only
Bucket had retainOnDelete). That made taking over pre-existing radosgw state
unsafe. Make adoption first-class.

- add retainOnDelete to ObjectStoreUser and BucketAccess (dedicated users), so
  deleting the CRD orphans the RGW user instead of deleting it (symmetric with
  Bucket)
- merge bucket policy instead of replacing it: the operator marks its own
  statements with a cephrgwop* Sid and preserves any statement it does not own,
  so adopting a bucket with a hand-written policy keeps it; add Bucket
  managePolicy (default true) to opt out of policy management entirely
- only reconcile user attributes the spec sets: DisplayName when non-empty and
  Suspended is now an optional *bool, so adopting a user does not reset them
- record adoption: ObjectStoreUser/Bucket status.adopted (+ printcolumn) is true
  when the RGW object already existed on first reconcile
- add GetBucketPolicy + MergeBucketPolicy; keyed adoption detection off the
  status identity field so a Pending owner wait does not mislabel it
- regenerate CRDs/deepcopy; add docs/adoption.md and
  config/samples/05-adoption.yaml; cover the merge in policy_test.go

Claude-Session: https://claude.ai/code/session_016CEncETbf8cvy1PhsHfFHM
2026-07-25 00:15:10 +10:00

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6.7 KiB
Markdown

# cephrgw-operator
A Kubernetes operator that provisions Ceph RGW (S3) **buckets** and **access
keys** declaratively, talking **directly to radosgw** the way the CLI does. You
describe a bucket, its owner, and who may read or write it as custom resources;
the operator creates the RGW users and bucket, delivers the access/secret keys
into Kubernetes Secrets, and maintains the bucket's S3 policy.
It uses native Go libraries against radosgw (e.g.
`https://radosgw.service.consul:443`) — no manager dashboard, no RADOS access,
no admin socket, no in-cluster Ceph required:
- **[go-ceph](https://github.com/ceph/go-ceph) `rgw/admin`** drives the RGW
**Admin Ops API** (`/admin/...`) for users, keys, quotas and bucket
info/removal — pure Go, no cgo.
- **[aws-sdk-go-v2](https://github.com/aws/aws-sdk-go-v2)** drives the **S3 API**
for bucket creation, versioning, policy, tagging and object lock — the
operations the Admin Ops API does not expose. These are signed as the bucket
**owner**, so the owner owns the bucket directly.
## Custom resources
| Kind | Short | Purpose |
|------|-------|---------|
| `ObjectStoreUser` | `osu` | An RGW S3 user. The operator creates it and writes its key pair into a Secret. |
| `Bucket` | `bkt` | An S3 bucket owned by an `ObjectStoreUser`. Owns the bucket's aggregate S3 policy. |
| `BucketAccess` | `ba` | Grants a user `read-only`, `read-write` or `full` access to a `Bucket`, delivering RW/RO keys. |
### How access levels work
The bucket **owner** (`Bucket.spec.ownerRef`) always has full control. Each
`BucketAccess` adds a principal to the bucket's S3 policy:
- `read-only``s3:GetObject`, `s3:ListBucket` and friends.
- `read-write` → read plus `s3:PutObject` / `s3:DeleteObject` / multipart.
- `full``s3:*` on the bucket and its objects.
If a `BucketAccess` omits `userRef`, the operator provisions a **dedicated** RGW
user for that grant and writes its keys into `spec.secretName` (default
`<name>-rgw`). If `userRef` names an existing `ObjectStoreUser`, that user's own
credential Secret is reused and only the policy is extended.
#### Fine-grained grants
The level is the ergonomic default; four optional fields on `BucketAccess`
refine it (see `config/samples/04-access-fine-grained.yaml`):
- `spec.paths` — scope object access to key prefixes; each becomes the resource
`<bucket>/<prefix>*`. The bucket-level `ListBucket` still spans the whole
bucket.
- `spec.actions` — grant exactly these S3 actions instead of the level's set (on
the bucket and its, optionally prefixed, objects).
- `spec.conditions``sourceIPs` (an `aws:SourceIp` CIDR allowlist) and
`secureTransportOnly` (require TLS).
- `spec.rawStatements` — an escape hatch of raw S3 policy statements
(`effect`/`actions`/`resources`/`conditions`) merged for this grant's
principal. When set, `level`, `actions`, `paths` and `conditions` are ignored;
resources without an `arn:` prefix are treated as bucket-relative key prefixes.
RGW honours S3 bucket policy on **Reef 18.2+ / Squid**; condition-key support is
a subset of AWS, so validate exotic conditions against your cluster.
### Adopting existing buckets and users
The operator can take over buckets/users that already exist in radosgw and hand
them back without deleting them. In short: matching CRDs manage the resource in
place (no recreation, keys reused, `status.adopted: true`), the bucket policy is
**merged** so an existing hand-written policy is preserved (`spec.managePolicy:
false` opts out entirely), and `spec.retainOnDelete` on `ObjectStoreUser` /
`Bucket` / `BucketAccess` orphans the RGW object instead of deleting it. See
**[docs/adoption.md](docs/adoption.md)** and
`config/samples/05-adoption.yaml`.
The `Bucket` controller renders the policy as the **union of every ready
`BucketAccess`** that targets it, so the result is convergent regardless of the
order objects are created or deleted. It watches `BucketAccess` and
`ObjectStoreUser`, re-reconciling the bucket whenever a grant or user changes.
```
ObjectStoreUser ──admin PUT /admin/user──────▶ Secret (AK/SK)
Bucket ──S3 CreateBucket (as owner)─▶ owns S3 policy
BucketAccess ──admin PUT /admin/user──────▶ Secret (AK/SK, RW or RO)
└────── enqueues Bucket ──▶ S3 PutBucketPolicy (aggregate)
```
## Credential Secrets
Every credential Secret carries the conventional keys, ready to mount straight
into a workload:
- `AWS_ACCESS_KEY_ID`, `AWS_SECRET_ACCESS_KEY`
- `RGW_UID`
- `S3_ENDPOINT`, `BUCKET_HOST` (when `CEPH_RGW_ENDPOINT` is set)
- `BUCKET_NAME` (on `BucketAccess` Secrets)
Secrets are owner-referenced by the resource that produced them, so they are
garbage-collected when the resource is deleted.
## Prerequisites
The operator needs an RGW user with admin caps (`users=*;buckets=*`) and its
access/secret key, the radosgw endpoint, and (for `read-only`/non-owner
`read-write` grants) Ceph **Reef 18.2+ / Squid**. See
**[docs/ceph-setup.md](docs/ceph-setup.md)** for the exact commands and the
`cephrgw-credentials` Secret schema.
## Quickstart
```sh
kubectl apply -f config/samples/00-owner-user.yaml
kubectl apply -f config/samples/01-bucket.yaml
kubectl apply -f config/samples/02-access-readonly.yaml
kubectl apply -f config/samples/03-access-readwrite.yaml
kubectl get osu,bkt,ba
kubectl get secret app-data-ro-rgw -o jsonpath='{.data.AWS_ACCESS_KEY_ID}' | base64 -d
```
## Development
```sh
make generate # regenerate deepcopy, CRDs and RBAC from kubebuilder markers
make build # build the operator binary
make test # go test -race
make lint fmt # go vet / gofmt
```
### Local (kind)
```sh
kind create cluster --name cephrgw
docker build -t cephrgw-operator:dev -f Dockerfile.operator .
kind load docker-image cephrgw-operator:dev --name cephrgw
kubectl apply -f config/crd/bases/
kubectl apply -f hack/kind/manifests/ # edit the Secret first
```
## CI
Woodpecker runs `pre-commit` (gofmt + vet), `test`, and a dry-run image `build`
on pull requests; pushing a `v*` tag builds and pushes
`git.unkin.net/unkin/cephrgw-operator` to the Gitea registry. Bump a release
with `make patch|minor|major`.
## Notes & caveats
- **Policy clearing.** Removing the last `BucketAccess` issues an S3
`DeleteBucketPolicy`. A `NoSuchBucketPolicy` response is treated as already
clear. Adding/replacing grants always works.
- **Per-bucket quota.** `Bucket.spec.quota` is applied as the owner's default
bucket quota via the Admin Ops API, which is per-owner rather than strictly
per-bucket. Use distinct owners if you need independent bucket quotas.
- **Immutability.** `bucketName`, an `ObjectStoreUser`'s `uid`, and object lock
are fixed at creation; changing them on an existing object has no effect.