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

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.

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

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’ve successfully removed the container, you’ll 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