Documentation

    PLEASE NOTE: This document applies to v1.2 version and not to the latest stable release v1.3

    Documentation for other releases can be found by using the version selector in the left bottom of any doc page.

    Object Storage

    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.

    Create an 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 bluestore 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
        erasureCoded:
          dataChunks: 2
          codingChunks: 1
      preservePoolsOnDelete: true
      gateway:
        type: s3
        sslCertificateRef:
        port: 80
        securePort:
        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 the object store
    kubectl create -f object.yaml
    
    # To confirm the object store is configured, wait for the rgw pod to start
    kubectl -n rook-ceph get pod -l app=rook-ceph-rgw
    

    Create a Bucket

    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
    provisioner: ceph.rook.io/bucket
    reclaimPolicy: Delete
    parameters:
      objectStoreName: my-store
      objectStoreNamespace: rook-ceph
      region: us-east-1
    
    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-Ceph 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 yaml | grep BUCKET_HOST | awk '{print $2}')
    export AWS_ACCESS_KEY_ID=$(kubectl -n default get secret ceph-bucket -o yaml | grep AWS_ACCESS_KEY_ID | awk '{print $2}' | base64 --decode)
    export AWS_SECRET_ACCESS_KEY=$(kubectl -n default get secret ceph-bucket -o yaml | grep AWS_SECRET_ACCESS_KEY | awk '{print $2}' | base64 --decode)
    

    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 AWS_ENDPOINT=<endpoint>
    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.
    • Endpoint: The endpoint where the rgw service is listening. Run kubectl -n rook-ceph get svc rook-ceph-rgw-my-store, then combine the clusterIP and 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
    export AWS_ENDPOINT=10.104.35.31:80
    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.

    Install s3cmd

    To test the CephObjectStore we will install the s3cmd tool into the toolbox pod.

    yum --assumeyes install s3cmd
    

    PUT or GET an object

    Upload a file to the newly created bucket

    echo "Hello Rook" > /tmp/rookObj
    s3cmd put /tmp/rookObj --no-ssl --host=${AWS_HOST} --host-bucket=  s3://rookbucket
    

    Download and verify the file from the bucket

    s3cmd get s3://rookbucket/rookObj /tmp/rookObj-download --no-ssl --host=${AWS_HOST} --host-bucket=
    cat /tmp/rookObj-download
    

    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 yaml | grep AccessKey | awk '{print $2}' | base64 --decode
    kubectl -n rook-ceph get secret rook-ceph-object-user-my-store-my-user -o yaml | grep SecretKey | awk '{print $2}' | base64 --decode