my-rook-config/Documentation/Storage-Configuration/Object-Storage-RGW/object-storage.md

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Object Storage Overview

Object storage exposes an S3 API to the storage cluster for applications to put and get data.

Prerequisites

This guide assumes a Rook cluster as explained in the Quickstart.

Configure an Object Store

Rook can configure the Ceph Object Store for several different scenarios. See each linked section for the configuration details.

1. Create a local object store with dedicated Ceph pools. This option is recommended if a single object store is required, and is the simplest to get started.
2. Create one or more object stores with shared Ceph pools. This option is recommended when multiple object stores are required.
3. Connect to an RGW service in an external Ceph cluster, rather than create a local object store.
4. Configure RGW Multisite to synchronize buckets between object stores in different clusters.

!!! note Updating the configuration of an object store between these types is not supported.

Create a Local Object Store

The below sample will create a CephObjectStore that starts the RGW service in the cluster with an S3 API.

!!! note This sample requires at least 3 OSDs, with each OSD located on a different node.

The OSDs must be located on different nodes, because the failureDomain is set to host and the erasureCoded chunk settings require at least 3 different OSDs (2 dataChunks + 1 codingChunks).

See the Object Store CRD, for more detail on the settings available for a CephObjectStore.

apiVersion: ceph.rook.io/v1
kind: CephObjectStore
metadata:
  name: my-store
  namespace: rook-ceph
spec:
  metadataPool:
    failureDomain: host
    replicated:
      size: 3
  dataPool:
    failureDomain: host
    # For production it is recommended to use more chunks, such as 4+2 or 8+4
    erasureCoded:
      dataChunks: 2
      codingChunks: 1
  preservePoolsOnDelete: true
  gateway:
    # sslCertificateRef:
    port: 80
    # securePort: 443
    instances: 1

After the CephObjectStore is created, the Rook operator will then create all the pools and other resources necessary to start the service. This may take a minute to complete.

Create an object store:

kubectl create -f object.yaml

To confirm the object store is configured, wait for the RGW pod(s) to start:

kubectl -n rook-ceph get pod -l app=rook-ceph-rgw

To consume the object store, continue below in the section to Create a bucket.

Create Local Object Store(s) with Shared Pools

The below sample will create one or more object stores. Shared Ceph pools will be created, which reduces the overhead of additional Ceph pools for each additional object store.

Data isolation is enforced between the object stores with the use of Ceph RADOS namespaces. The separate RADOS namespaces do not allow access of the data across object stores.

!!! note This sample requires at least 3 OSDs, with each OSD located on a different node.

The OSDs must be located on different nodes, because the failureDomain is set to host and the erasureCoded chunk settings require at least 3 different OSDs (2 dataChunks + 1 codingChunks).

Shared Pools

Create the shared pools that will be used by each of the object stores.

!!! note If object stores have been previously created, the first pool below (.rgw.root) does not need to be defined again as it would have already been created with an existing object store. There is only one .rgw.root pool existing to store metadata for all object stores.

apiVersion: ceph.rook.io/v1
kind: CephBlockPool
metadata:
  name: rgw-root
  namespace: rook-ceph # namespace:cluster
spec:
  name: .rgw.root
  failureDomain: host
  replicated:
    size: 3
    requireSafeReplicaSize: false
  parameters:
    pg_num: "8"
  application: rgw
---
apiVersion: ceph.rook.io/v1
kind: CephBlockPool
metadata:
  name: rgw-meta-pool
  namespace: rook-ceph # namespace:cluster
spec:
  failureDomain: host
  replicated:
    size: 3
    requireSafeReplicaSize: false
  parameters:
    pg_num: "8"
  application: rgw
---
apiVersion: ceph.rook.io/v1
kind: CephBlockPool
metadata:
  name: rgw-data-pool
  namespace: rook-ceph # namespace:cluster
spec:
  failureDomain: osd
  erasureCoded:
    # For production it is recommended to use more chunks, such as 4+2 or 8+4
    dataChunks: 2
    codingChunks: 1
  application: rgw

Create the shared pools:

kubectl create -f object-shared-pools.yaml

Create Each Object Store

After the pools have been created above, create each object store to consume the shared pools.

apiVersion: ceph.rook.io/v1
kind: CephObjectStore
metadata:
  name: store-a
  namespace: rook-ceph # namespace:cluster
spec:
  sharedPools:
    metadataPoolName: rgw-meta-pool
    dataPoolName: rgw-data-pool
    preserveRadosNamespaceDataOnDelete: true
  gateway:
    # sslCertificateRef:
    port: 80
    instances: 1

Create the object store:

kubectl create -f object-a.yaml

To confirm the object store is configured, wait for the RGW pod(s) to start:

kubectl -n rook-ceph get pod -l rgw=store-a

Additional object stores can be created based on the same shared pools by simply changing the name of the CephObjectStore. In the example manifests folder, two object store examples are provided: object-a.yaml and object-b.yaml.

To consume the object store, continue below in the section to Create a bucket. Modify the default example object store name from my-store to the alternate name of the object store such as store-a in this example.

Connect to an External Object Store

Rook can connect to existing RGW gateways to work in conjunction with the external mode of the CephCluster CRD. First, create a rgw-admin-ops-user user in the Ceph cluster with the necessary caps:

radosgw-admin user create --uid=rgw-admin-ops-user --display-name="RGW Admin Ops User" --caps="buckets=*;users=*;usage=read;metadata=read;zone=read" --rgw-realm=<realm-name> --rgw-zonegroup=<zonegroup-name> --rgw-zone=<zone-name>

The rgw-admin-ops-user user is required by the Rook operator to manage buckets and users via the admin ops and s3 api. The multisite configuration needs to be specified only if the admin sets up multisite for RGW.

Then create a secret with the user credentials:

kubectl -n rook-ceph create secret generic --type="kubernetes.io/rook" rgw-admin-ops-user --from-literal=accessKey=<access key of the user> --from-literal=secretKey=<secret key of the user>

For an external CephCluster, configure Rook to consume external RGW servers with the following:

apiVersion: ceph.rook.io/v1
kind: CephObjectStore
metadata:
  name: external-store
  namespace: rook-ceph
spec:
  gateway:
    port: 8080
    externalRgwEndpoints:
      - ip: 192.168.39.182
        # hostname: example.com

See object-external.yaml for a more detailed example.

Even though multiple externalRgwEndpoints can be specified, it is best to use a single endpoint. Only the first endpoint in the list will be advertised to any consuming resources like CephObjectStoreUsers, ObjectBucketClaims, or COSI resources. If there are multiple external RGW endpoints, add load balancer in front of them, then use the single load balancer endpoint in the externalRgwEndpoints list.

Object store endpoint

The CephObjectStore resource status.info contains endpoint (and secureEndpoint) fields, which report the endpoint that can be used to access the object store as a client. This endpoint is also advertised as the default endpoint for CephObjectStoreUsers, ObjectBucketClaims, and Container Object Store Interface (COSI) resources.

Each object store also creates a Kubernetes service that can be used as a client endpoint from within the Kubernetes cluster. The DNS name of the service is rook-ceph-rgw-<objectStoreName>.<objectStoreNamespace>.svc. This service DNS name is the default endpoint (and secureEndpoint).

For external clusters, the default endpoint is the first spec.gateway.externalRgwEndpoint instead of the service DNS name.

The advertised endpoint can be overridden using advertiseEndpoint in the spec.hosting config.

Rook always uses the advertised endpoint to perform management operations against the object store. When TLS is enabled, the TLS certificate must always specify the endpoint DNS name to allow secure management operations.

Create a Bucket

!!! info This document is a guide for creating bucket with an Object Bucket Claim (OBC). To create a bucket with the experimental COSI Driver, see the COSI documentation.

Now that the object store is configured, next we need to create a bucket where a client can read and write objects. A bucket can be created by defining a storage class, similar to the pattern used by block and file storage. First, define the storage class that will allow object clients to create a bucket. The storage class defines the object storage system, the bucket retention policy, and other properties required by the administrator. Save the following as storageclass-bucket-delete.yaml (the example is named as such due to the Delete reclaim policy).

apiVersion: storage.k8s.io/v1
kind: StorageClass
metadata:
   name: rook-ceph-bucket
# Change "rook-ceph" provisioner prefix to match the operator namespace if needed
provisioner: rook-ceph.ceph.rook.io/bucket
reclaimPolicy: Delete
parameters:
  objectStoreName: my-store
  objectStoreNamespace: rook-ceph

If you’ve deployed the Rook operator in a namespace other than rook-ceph, change the prefix in the provisioner to match the namespace you used. For example, if the Rook operator is running in the namespace my-namespace the provisioner value should be my-namespace.ceph.rook.io/bucket.

kubectl create -f storageclass-bucket-delete.yaml

Based on this storage class, an object client can now request a bucket by creating an Object Bucket Claim (OBC). When the OBC is created, the Rook bucket provisioner will create a new bucket. Notice that the OBC references the storage class that was created above. Save the following as object-bucket-claim-delete.yaml (the example is named as such due to the Delete reclaim policy):

apiVersion: objectbucket.io/v1alpha1
kind: ObjectBucketClaim
metadata:
  name: ceph-bucket
spec:
  generateBucketName: ceph-bkt
  storageClassName: rook-ceph-bucket

kubectl create -f object-bucket-claim-delete.yaml

Now that the claim is created, the operator will create the bucket as well as generate other artifacts to enable access to the bucket. A secret and ConfigMap are created with the same name as the OBC and in the same namespace. The secret contains credentials used by the application pod to access the bucket. The ConfigMap contains bucket endpoint information and is also consumed by the pod. See the Object Bucket Claim Documentation for more details on the CephObjectBucketClaims.

Client Connections

The following commands extract key pieces of information from the secret and configmap:"

#config-map, secret, OBC will part of default if no specific name space mentioned
export AWS_HOST=$(kubectl -n default get cm ceph-bucket -o jsonpath='{.data.BUCKET_HOST}')
export PORT=$(kubectl -n default get cm ceph-bucket -o jsonpath='{.data.BUCKET_PORT}')
export BUCKET_NAME=$(kubectl -n default get cm ceph-bucket -o jsonpath='{.data.BUCKET_NAME}')
export AWS_ACCESS_KEY_ID=$(kubectl -n default get secret ceph-bucket -o jsonpath='{.data.AWS_ACCESS_KEY_ID}' | base64 --decode)
export AWS_SECRET_ACCESS_KEY=$(kubectl -n default get secret ceph-bucket -o jsonpath='{.data.AWS_SECRET_ACCESS_KEY}' | base64 --decode)

If any hosting.dnsNames are set in the CephObjectStore CRD, S3 clients can access buckets in virtual-host-style. Otherwise, S3 clients must be configured to use path-style access.

Consume the Object Storage

Now that you have the object store configured and a bucket created, you can consume the object storage from an S3 client.

This section will guide you through testing the connection to the CephObjectStore and uploading and downloading from it. Run the following commands after you have connected to the Rook toolbox.

Connection Environment Variables

To simplify the s3 client commands, you will want to set the four environment variables for use by your client (ie. inside the toolbox). See above for retrieving the variables for a bucket created by an ObjectBucketClaim.

export AWS_HOST=<host>
export PORT=<port>
export AWS_ACCESS_KEY_ID=<accessKey>
export AWS_SECRET_ACCESS_KEY=<secretKey>

• Host: The DNS host name where the rgw service is found in the cluster. Assuming you are using the default rook-ceph cluster, it will be rook-ceph-rgw-my-store.rook-ceph.svc.
• Port: The endpoint where the rgw service is listening. Run kubectl -n rook-ceph get svc rook-ceph-rgw-my-store, to get the port.
• Access key: The user's access_key as printed above
• Secret key: The user's secret_key as printed above

The variables for the user generated in this example might be:

export AWS_HOST=rook-ceph-rgw-my-store.rook-ceph.svc
export PORT=80
export AWS_ACCESS_KEY_ID=XEZDB3UJ6X7HVBE7X7MA
export AWS_SECRET_ACCESS_KEY=7yGIZON7EhFORz0I40BFniML36D2rl8CQQ5kXU6l

The access key and secret key can be retrieved as described in the section above on client connections or below in the section creating a user if you are not creating the buckets with an ObjectBucketClaim.

Configure s5cmd

To test the CephObjectStore, set the object store credentials in the toolbox pod that contains the s5cmd tool.

!!! important The default toolbox.yaml does not contain the s5cmd. The toolbox must be started with the rook operator image (toolbox-operator-image), which does contain s5cmd.

kubectl create -f deploy/examples/toolbox-operator-image.yaml
mkdir ~/.aws
cat > ~/.aws/credentials << EOF
[default]
aws_access_key_id = ${AWS_ACCESS_KEY_ID}
aws_secret_access_key = ${AWS_SECRET_ACCESS_KEY}
EOF

PUT or GET an object

Upload a file to the newly created bucket

echo "Hello Rook" > /tmp/rookObj
s5cmd --endpoint-url http://$AWS_HOST:$PORT cp /tmp/rookObj s3://$BUCKET_NAME

Download and verify the file from the bucket

s5cmd --endpoint-url http://$AWS_HOST:$PORT cp s3://$BUCKET_NAME/rookObj /tmp/rookObj-download
cat /tmp/rookObj-download

Monitoring health

Rook configures health probes on the deployment created for CephObjectStore gateways. Refer to the CRD document for information about configuring the probes and monitoring the deployment status.

Access External to the Cluster

Rook sets up the object storage so pods will have access internal to the cluster. If your applications are running outside the cluster, you will need to setup an external service through a NodePort.

First, note the service that exposes RGW internal to the cluster. We will leave this service intact and create a new service for external access.

$ kubectl -n rook-ceph get service rook-ceph-rgw-my-store
NAME                     CLUSTER-IP   EXTERNAL-IP   PORT(S)     AGE
rook-ceph-rgw-my-store   10.3.0.177   <none>        80/TCP      2m

Save the external service as rgw-external.yaml:

apiVersion: v1
kind: Service
metadata:
  name: rook-ceph-rgw-my-store-external
  namespace: rook-ceph
  labels:
    app: rook-ceph-rgw
    rook_cluster: rook-ceph
    rook_object_store: my-store
spec:
  ports:
  - name: rgw
    port: 80
    protocol: TCP
    targetPort: 80
  selector:
    app: rook-ceph-rgw
    rook_cluster: rook-ceph
    rook_object_store: my-store
  sessionAffinity: None
  type: NodePort

Now create the external service.

kubectl create -f rgw-external.yaml

See both rgw services running and notice what port the external service is running on:

$ kubectl -n rook-ceph get service rook-ceph-rgw-my-store rook-ceph-rgw-my-store-external
NAME                              TYPE        CLUSTER-IP       EXTERNAL-IP   PORT(S)        AGE
rook-ceph-rgw-my-store            ClusterIP   10.104.82.228    <none>        80/TCP         4m
rook-ceph-rgw-my-store-external   NodePort    10.111.113.237   <none>        80:31536/TCP   39s

Internally the rgw service is running on port 80. The external port in this case is 31536. Now you can access the CephObjectStore from anywhere! All you need is the hostname for any machine in the cluster, the external port, and the user credentials.

Create a User

If you need to create an independent set of user credentials to access the S3 endpoint, create a CephObjectStoreUser. The user will be used to connect to the RGW service in the cluster using the S3 API. The user will be independent of any object bucket claims that you might have created in the earlier instructions in this document.

See the Object Store User CRD for more detail on the settings available for a CephObjectStoreUser.

apiVersion: ceph.rook.io/v1
kind: CephObjectStoreUser
metadata:
  name: my-user
  namespace: rook-ceph
spec:
  store: my-store
  displayName: "my display name"

When the CephObjectStoreUser is created, the Rook operator will then create the RGW user on the specified CephObjectStore and store the Access Key and Secret Key in a kubernetes secret in the same namespace as the CephObjectStoreUser.

# Create the object store user
kubectl create -f object-user.yaml

# To confirm the object store user is configured, describe the secret
$ kubectl -n rook-ceph describe secret rook-ceph-object-user-my-store-my-user
Name:    rook-ceph-object-user-my-store-my-user
Namespace:  rook-ceph
Labels:     app=rook-ceph-rgw
            rook_cluster=rook-ceph
            rook_object_store=my-store
Annotations:  <none>

Type: kubernetes.io/rook

Data
====
AccessKey:  20 bytes
SecretKey:  40 bytes

The AccessKey and SecretKey data fields can be mounted in a pod as an environment variable. More information on consuming kubernetes secrets can be found in the K8s secret documentation

To directly retrieve the secrets:

kubectl -n rook-ceph get secret rook-ceph-object-user-my-store-my-user -o jsonpath='{.data.AccessKey}' | base64 --decode
kubectl -n rook-ceph get secret rook-ceph-object-user-my-store-my-user -o jsonpath='{.data.SecretKey}' | base64 --decode

Enable TLS

TLS is critical for securing object storage data access, and it is assumed as a default by many S3 clients. TLS is enabled for CephObjectStores by configuring gateway options. Set securePort, and give Rook access to a TLS certificate using sslCertificateRef. caBundleRef may be necessary as well to give the deployed gateway (RGW) access to the TLS certificate's CA signing bundle.

Ceph RGW only supports a single TLS certificate. If the given TLS certificate is a concatenation of multiple certificates, only the first certificate will be used by the RGW as the server certificate. Therefore, the TLS certificate given must include all endpoints that clients will use for access as subject alternate names (SANs).

The CephObjectStore service endpoint must be added as a SAN on the TLS certificate. If it is not possible to add the service DNS name as a SAN on the TLS certificate, set hosting.advertiseEndpoint to a TLS-approved endpoint to help ensure Rook and clients use secure data access.

!!! note OpenShift users can use add service.beta.openshift.io/serving-cert-secret-name as a service annotation instead of using sslCertificateRef.

Virtual host-style Bucket Access

The Ceph Object Gateway supports accessing buckets using virtual host-style addressing, which allows addressing buckets using the bucket name as a subdomain in the endpoint.

AWS has deprecated the the alternative path-style addressing mode which is Rook and Ceph's default. As a result, many end-user applications have begun to remove path-style support entirely. Many production clusters will have to enable virtual host-style address.

Virtual host-style addressing requires 2 things:

1. An endpoint that supports wildcard addressing
2. CephObjectStore hosting configuration.

Wildcard addressing can be configured in myriad ways. Some options:

• Kubernetes ingress loadbalancer
• Openshift DNS operator

The minimum recommended hosting configuration is exemplified below. It is important to ensure that Rook advertises the wildcard-addressable endpoint as a priority over the default. TLS is also recommended for security, and the configured TLS certificate should specify the advertise endpoint.

spec:
  ...
  hosting:
    advertiseEndpoint:
      dnsName: my.wildcard.addressable.endpoint.com
      port: 443
      useTls: true

A more complex hosting configuration is exemplified below. In this example, two wildcard-addressable endpoints are available. One is a wildcard-addressable ingress service that is accessible to clients outside of the Kubernetes cluster (s3.ingress.domain.com). The other is a wildcard-addressable Kubernetes cluster service (s3.rook-ceph.svc). The cluster service is the preferred advertise endpoint because the internal service avoids the possibility of the ingress service's router being a bottleneck for S3 client operations.

spec:
  ...
  hosting:
    advertiseEndpoint:
      dnsName: s3.rook-ceph.svc
      port: 443
      useTls: true
  dnsNames:
    - s3.ingress.domain.com

Object Multisite

Multisite is a feature of Ceph that allows object stores to replicate its data over multiple Ceph clusters.

Multisite also allows object stores to be independent and isolated from other object stores in a cluster.

For more information on multisite please read the ceph multisite overview for how to run it.