Append upload files using the Ruby SDK - Object Storage Service

Append upload adds content to the end of an appendable object using the AppendObject API. Use it for scenarios such as writing log entries from a running process or sequentially appending chunks of streaming data.

Usage notes

The examples in this topic use the public endpoint of the China (Hangzhou) region. To access OSS from other Alibaba Cloud services in the same region, use the internal endpoint instead. For a list of supported regions and endpoints, see Regions and endpoints.
The examples create an OSSClient instance using an OSS endpoint. To create an OSSClient instance using a custom domain name or Security Token Service (STS), see Configuration examples for common scenarios.

Bucket#append_object behaves differently depending on whether the target object exists and its type:

Condition	Result
Object does not exist	Creates a new appendable object and appends the content
Object is appendable and the position matches its current size	Appends content to the end of the object
Object is appendable but the position does not match its current size	Throws `PositionNotEqualToLength`
Object exists but is not appendable (for example, uploaded via simple upload)	Throws `ObjectNotAppendable`

Permissions

By default, an Alibaba Cloud account has full permissions. RAM users and RAM roles have no permissions by default. Grant the required permissions through RAM Policy or Bucket policies.

API	Required action	Description
AppendObject	`oss:PutObject`	Upload an object by appending to an existing object
AppendObject	`oss:PutObjectTagging`	Required when specifying object tags via `x-oss-tagging`

Sample code

Initialize the client

require 'aliyun/oss'

client = Aliyun::OSS::Client.new(
  # Replace with your actual region endpoint.
  endpoint: 'https://oss-cn-hangzhou.aliyuncs.com',
  # Read credentials from environment variables. Set OSS_ACCESS_KEY_ID and
  # OSS_ACCESS_KEY_SECRET before running this code.
  access_key_id: ENV['OSS_ACCESS_KEY_ID'],
  access_key_secret: ENV['OSS_ACCESS_KEY_SECRET']
)

bucket = client.get_bucket('examplebucket')

Append content to an object

Use a block to stream content into the object. Pass 0 as the position for the first append. Each call returns the position to use for the next append.

# First append: position must be 0 for a new appendable object.
next_pos = bucket.append_object('my-object', 0) do |stream|
  100.times { |i| stream << i.to_s }
end

# Subsequent appends: use next_pos from the previous call.
next_pos = bucket.append_object('my-object', next_pos) do |stream|
  stream << 'additional content'
end

Append a local file

To append the contents of a local file, pass the :file option instead of a block.

# First append from a local file.
next_pos = bucket.append_object('my-object', 0, :file => 'local-file-1')

# Chain multiple files using the returned position.
next_pos = bucket.append_object('my-object', next_pos, :file => 'local-file-2')

References

For the full AppendObject API reference, see AppendObject.