Container Operations¶

A container is a mechanism for storing data objects. An account may have many containers, but container names must be unique. This API enables a client to create a container, set access controls and metadata, retrieve a container’s contents, and delete a container. Since this API makes requests related to information in a particular user’s account, all requests in this API must be authenticated unless a container’s access control is deliberately made publicly accessible (i.e., allows anonymous requests).

Note

The Amazon S3 API uses the term ‘bucket’ to describe a data container. When you hear someone refer to a ‘bucket’ within the Swift API, the term ‘bucket’ may be construed as the equivalent of the term ‘container.’

One facet of object storage is that it does not support hierarchical paths or directories. Instead, it supports one level consisting of one or more containers, where each container may have objects. The RADOS Gateway’s Swift-compatible API supports the notion of ‘pseudo-hierarchical containers,’ which is a means of using object naming to emulate a container (or directory) hierarchy without actually implementing one in the storage system. You may name objects with pseudo-hierarchical names (e.g., photos/buildings/empire-state.jpg), but container names cannot contain a forward slash (/) character.

Create a Container¶

To create a new container, make a PUT request with the API version, account, and the name of the new container. The container name must be unique, must not contain a forward-slash (/) character, and should be less than 256 bytes. You may include access control headers and metadata headers in the request. The operation is idempotent; that is, if you make a request to create a container that already exists, it will return with a HTTP 202 return code, but will not create another container.

Syntax¶

PUT /{api version}/{account}/{container} HTTP/1.1
Host: {fqdn}
X-Auth-Token: {auth-token}
X-Container-Read: {comma-separated-uids}
X-Container-Write: {comma-separated-uids}
X-Container-Meta-{key}: {value}

Headers¶

X-Container-Read

Description: The user IDs with read permissions for the container.
Type: Comma-separated string values of user IDs.
Required: No

X-Container-Write

Description: The user IDs with write permissions for the container.
Type: Comma-separated string values of user IDs.
Required: No

X-Container-Meta-{key}

Description: A user-defined meta data key that takes an arbitrary string value.
Type: String
Required: No

HTTP Response¶

If a container with the same name already exists, and the user is the container owner then the operation will succeed. Otherwise the operation will fail.

409

Description: The container already exists under a different user’s ownership.
Status Code: BucketAlreadyExists

List a Container’s Objects¶

To list the objects within a container, make a GET request with the with the API version, account, and the name of the container. You can specify query parameters to filter the full list, or leave out the parameters to return a list of the first 10,000 object names stored in the container.

Syntax¶

GET /{api version}/{container} HTTP/1.1
     Host: {fqdn}
     X-Auth-Token: {auth-token}

Parameters¶

format

Description: Defines the format of the result.
Type: String
Valid Values: json | xml
Required: No

prefix

Description: Limits the result set to objects beginning with the specified prefix.
Type: String
Required: No

marker

Description: Returns a list of results greater than the marker value.
Type: String
Required: No

limit

Description: Limits the number of results to the specified value.
Type: Integer
Valid Range: 0 - 10,000
Required: No

delimiter

Description: The delimiter between the prefix and the rest of the object name.
Type: String
Required: No

path

Description: The pseudo-hierarchical path of the objects.
Type: String
Required: No

allow_unordered

Description: Allows the results to be returned unordered to reduce computation overhead. Cannot be used with delimiter.
Type: Boolean
Required: No
Non-Standard Extension: Yes

Response Entities¶

container

Description: The container.
Type: Container

object

Description: An object within the container.
Type: Container

name

Description: The name of an object within the container.
Type: String

hash

Description: A hash code of the object’s contents.
Type: String

last_modified

Description: The last time the object’s contents were modified.
Type: Date

content_type

Description: The type of content within the object.
Type: String

Update a Container’s ACLs¶

When a user creates a container, the user has read and write access to the container by default. To allow other users to read a container’s contents or write to a container, you must specifically enable the user. You may also specify * in the X-Container-Read or X-Container-Write settings, which effectively enables all users to either read from or write to the container. Setting * makes the container public. That is it enables anonymous users to either read from or write to the container.

Note

If you are planning to expose public read ACL functionality for the Swift API, it is strongly recommended to include the Swift account name in the endpoint definition, so as to most closely emulate the behavior of native OpenStack Swift. To do so, set the ceph.conf configuration option rgw swift account in url = true, and update your Keystone endpoint to the URL suffix /v1/AUTH_%(tenant_id)s (instead of just /v1).

Syntax¶

POST /{api version}/{account}/{container} HTTP/1.1
Host: {fqdn}
     X-Auth-Token: {auth-token}
     X-Container-Read: *
     X-Container-Write: {uid1}, {uid2}, {uid3}

Request Headers¶

X-Container-Read

Description: The user IDs with read permissions for the container.
Type: Comma-separated string values of user IDs.
Required: No

X-Container-Write

Description: The user IDs with write permissions for the container.
Type: Comma-separated string values of user IDs.
Required: No

Add/Update Container Metadata¶

To add metadata to a container, make a POST request with the API version, account, and container name. You must have write permissions on the container to add or update metadata.

Syntax¶

POST /{api version}/{account}/{container} HTTP/1.1
Host: {fqdn}
     X-Auth-Token: {auth-token}
     X-Container-Meta-Color: red
     X-Container-Meta-Taste: salty

Request Headers¶

X-Container-Meta-{key}

Description: A user-defined meta data key that takes an arbitrary string value.
Type: String
Required: No

Enable Object Versioning for a Container¶

To enable object versioning a container, make a POST request with the API version, account, and container name. You must have write permissions on the container to add or update metadata.

Note

Object versioning support is not enabled in radosgw by default; you must set rgw swift versioning enabled = true in ceph.conf to enable this feature.

Syntax¶

POST /{api version}/{account}/{container} HTTP/1.1
Host: {fqdn}
     X-Auth-Token: {auth-token}
     X-Versions-Location: {archive-container}

Request Headers¶

X-Versions-Location

Description: The name of a container (the “archive container”) that will be used to store versions of the objects in the container that the POST request is made on (the “current container”). The archive container need not exist at the time it is being referenced, but once X-Versions-Location is set on the current container, and object versioning is thus enabled, the archive container must exist before any further objects are updated or deleted in the current container.

Note

X-Versions-Location is the only versioning-related header that radosgw interprets. X-History-Location, supported by native OpenStack Swift, is currently not supported by radosgw.
Type: String
Required: No (if this header is passed with an empty value, object versioning on the current container is disabled, but the archive container continues to exist.)

Delete a Container¶

To delete a container, make a DELETE request with the API version, account, and the name of the container. The container must be empty. If you’d like to check if the container is empty, execute a HEAD request against the container. Once you have successfully removed the container, you will be able to reuse the container name.

Syntax¶

DELETE /{api version}/{account}/{container} HTTP/1.1
Host: {fqdn}
X-Auth-Token: {auth-token}

HTTP Response¶

204

Description: The container was removed.
Status Code: NoContent