Versioning objects

Archiving and expiring versioned objects

Lifecycle configurations are permitted in a version-enabled bucket. However, unlike Amazon S3, new versions are subject to the archive rule in the same manner as regular objects. Objects are given a transition date when they are created, and are archived on their individual transition date, regardless of whether they are current or non-current versions. Overwriting an object does not affect the transition date of the previous version, and the new (current) version will be assigned a transition date.

It is not possible to use NoncurrentVersionTransition rules to archive only non-current versions of objects in a lifecycle configuration.

Immutable Object Storage (WORM)

The IBM COS implementation of Immutable Object Storage (that is, retention policies) is not permitted in buckets with versioning enabled. Attempts to create a retention policy will fail, as will attempts to enable versioning on a bucket with an retention policy.

Enable versioning on a bucket

curl -X "PUT" "https://$BUCKET.s3.$REGION.cloud-object-storage.appdomain.cloud/?versioning" \
     -H 'Authorization: bearer $TOKEN' \
     -H 'Content-MD5: 8qj8HSeDu3APPMQZVG06WQ==' \
     -H 'Content-Type: text/plain; charset=utf-8' \
     -d $'<VersioningConfiguration>
            <Status>Enabled</Status>
          </VersioningConfiguration>'

A successful request returns a 200 response.

Suspend versioning on a bucket

curl -X "PUT" "https://$BUCKET.s3.$REGION.cloud-object-storage.appdomain.cloud/?versioning" \
     -H 'Authorization: bearer $TOKEN' \
     -H 'Content-MD5: hxXDWuCDWB72Be0LG4XniQ==' \
     -H 'Content-Type: text/plain; charset=utf-8' \
     -d $'<VersioningConfiguration>
            <Status>Suspended</Status>
          </VersioningConfiguration>'

A successful request returns a 200 response.

List versions of objects in a bucket

curl -X "GET" "https://$BUCKET.s3.$REGION.cloud-object-storage.appdomain.cloud/?versions" \
     -H 'Authorization: bearer $TOKEN'

This returns an XML response body:

<ListVersionsResult>
   <IsTruncated>boolean</IsTruncated>
   <KeyMarker>string</KeyMarker>
   <VersionIdMarker>string</VersionIdMarker>
   <NextKeyMarker>string</NextKeyMarker>
   <NextVersionIdMarker>string</NextVersionIdMarker>
   <Version>
      <ETag>string</ETag>
      <IsLatest>boolean</IsLatest>
      <Key>string</Key>
      <LastModified>timestamp</LastModified>
      <Owner>
         <DisplayName>string</DisplayName>
         <ID>string</ID>
      </Owner>
      <Size>integer</Size>
      <StorageClass>string</StorageClass>
      <VersionId>string</VersionId>
   </Version>
   ...
   <DeleteMarker>
      <IsLatest>boolean</IsLatest>
      <Key>string</Key>
      <LastModified>timestamp</LastModified>
      <Owner>
         <DisplayName>string</DisplayName>
         <ID>string</ID>
      </Owner>
      <VersionId>string</VersionId>
   </DeleteMarker>
   ...
   <Name>string</Name>
   <Prefix>string</Prefix>
   <Delimiter>string</Delimiter>
   <MaxKeys>integer</MaxKeys>
   <CommonPrefixes>
      <Prefix>string</Prefix>
   </CommonPrefixes>
   ...
   <EncodingType>string</EncodingType>
</ListVersionsResult>

delimiter: A delimiter is a character that you specify to group keys. All keys that contain the same string between the prefix and the first occurrence of the delimiter are grouped under a single result element in CommonPrefixes. These groups are counted as one result against the max-keys limitation. These keys are not returned elsewhere in the response.

encoding-type: Requests COS to url-encode the object keys in the response. Object keys may contain any Unicode character; however, XML 1.0 parser cannot parse some characters, such as characters with an ASCII value from 0 to 10. For characters that are not supported in XML 1.0, you can add this parameter to request that COS encodes the keys in the response. Valid value: url.

key-marker: Specifies the key to start with when listing objects in a bucket.

max-keys: Sets the maximum number of keys returned in the response. By default the API returns up to 1,000 key names. The response might contain fewer keys but will never contain more.

prefix: Use this parameter to select only those keys that begin with the specified prefix.

version-id-marker: Specifies the object version you want to start listing from.

Operations on specific versions of objects

Several APIs make use of a new query parameter (?versionId=<VersionId>) that indicates which version of the object you are requesting. This parameter is used in the same manner for reading, deleting, checking metadata and tags, and restoring archived objects. For example, to read a version of an object foo with a version ID of L4kqtJlcpXroDVBH40Nr8X8gdRQBpUMLUo, the request might look like the following:

curl -X "GET" "https://$BUCKET.s3.$REGION.cloud-object-storage.appdomain.cloud/foo?versionId=L4kqtJlcpXroDVBH40Nr8X8gdRQBpUMLUo" \
     -H 'Authorization: bearer $TOKEN'

Deleting that object is done in the same manner.

curl -X "DELETE" "https://$BUCKET.s3.$REGION.cloud-object-storage.appdomain.cloud/foo?versionId=L4kqtJlcpXroDVBH40Nr8X8gdRQBpUMLUo" \
     -H 'Authorization: bearer $TOKEN'

For requests that already make use of a query parameter, the versionId parameter can be added to the end.

curl -X "GET" "https://$BUCKET.s3.$REGION.cloud-object-storage.appdomain.cloud/foo?tagging&versionId=L4kqtJlcpXroDVBH40Nr8X8gdRQBpUMLUo" \
     -H 'Authorization: bearer $TOKEN'

Server-side copying of object versions is supported, but uses a slightly different syntax. The query parameter is not added to the URL itself, but instead is appended to the x-amz-copy-source header. This is the same syntax as creating a part for a multipart part from a source object.

curl -X "PUT" "https://$BUCKET.s3.$REGION.cloud-object-storage.appdomain.cloud/<new-object-key>"
 -H "Authorization: bearer $TOKEN"
 -H "x-amz-copy-source: /<source-bucket>/<object-key>?versionId=L4kqtJlcpXroDVBH40Nr8X8gdRQBpUMLUo"

Python

Enabling versioning using the IBM COS SDK for Python can be done using either the high-level resource or low-level client syntax.

Using a resource:

#!/usr/bin/env python3

import ibm_boto3
from ibm_botocore.config import Config
from ibm_botocore.exceptions import ClientError

#Define constants
API_KEY = os.environ.get('IBMCLOUD_API_KEY')
SERVICE_INSTANCE = os.environ.get('SERVICE_INSTANCE_ID')
ENDPOINT = os.environ.get('ENDPOINT')

BUCKET = "my-versioning-bucket" # The bucket that will enable versioning.

#Create resource client with configuration info pulled from environment variables.
cos = ibm_boto3.resource("s3",
                         ibm_api_key_id=API_KEY,
                         ibm_service_instance_id=SERVICE_INSTANCE,
                         config=Config(signature_version="oauth"),
                         endpoint_url=ENDPOINT
                         )

versioning = cos.BucketVersioning(BUCKET)

versioning.enable()

Versioning for the bucket can then be suspended using versioning.suspend()

Using that same cos resource, all versions of objects could be listed using the following:

versions = s3.Bucket(BUCKET).object_versions.filter(Prefix=key)

for version in versions:
    obj = version.get()
    print(obj.get('VersionId'), obj.get('ContentLength'), obj.get('LastModified'))

Using a client:

#!/usr/bin/env python3

import ibm_boto3
from ibm_botocore.config import Config
from ibm_botocore.exceptions import ClientError

#Define constants
API_KEY = os.environ.get('IBMCLOUD_API_KEY')
SERVICE_INSTANCE = os.environ.get('SERVICE_INSTANCE_ID')
ENDPOINT = os.environ.get('ENDPOINT')

BUCKET = "my-versioning-bucket" # The bucket that will enable versioning.

#Create resource client with configuration info pulled from environment variables.
cosClient = ibm_boto3.client("s3",
                         ibm_api_key_id=API_KEY,
                         ibm_service_instance_id=SERVICE_INSTANCE,
                         config=Config(signature_version="oauth"),
                         endpoint_url=ENDPOINT
                         )

response = cosClient.put_bucket_versioning(
    Bucket=BUCKET,
    VersioningConfiguration={
        'Status': 'Enabled'
    }
)

Listing the versions of an object using the same client:

resp = cosClient.list_object_versions(Prefix='some-prefix', Bucket=BUCKET)

Note that the Python APIs are very flexible, and there are many different ways to accomplish the same task.

Node.js

Enabling versioning using the IBM COS SDK for Node.js:

const IBM = require('ibm-cos-sdk');

var config = {
    endpoint: '<endpoint>',
    apiKeyId: '<api-key>',
    serviceInstanceId: '<resource-instance-id>',
};

var cos = new IBM.S3(config);

var params = {
    Bucket: 'my-versioning-bucket', /* required */
    VersioningConfiguration: { /* required */
    Status: 'Enabled'
   },
};

s3.putBucketVersioning(params, function(err, data) {
   if (err) console.log(err, err.stack); // an error occurred
   else     console.log(data);           // successful response
});