Spectra S3 Python3 SDK

An SDK conforming to the Spectra S3 specification for Python 3.6

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Installing

To install the ds3_python3_sdk, either clone the latest code, or download a release bundle from Releases. Once the code has been download, cd into the bundle, and install it with sudo python3 setup.py install

Once setup.py completes the ds3_python3_sdk should be installed and available to be imported into python scripts.

Documentation

The documentation for the SDK can be found at http://spectralogic.github.io/ds3_python3_sdk/sphinx/v3.4.1/

SDK

The SDK provides an interface for a user to add Spectra S3 functionality to their existing or new python application. In order to take advantage of the SDK you need to import the ds3 python package and module. The following is an example that creates a Spectra S3 client from environment variables, creates a bucket, and lists all the buckets that are visible to the user.

from ds3 import ds3

client = ds3.createClientFromEnv()

client.put_bucket(ds3.PutBucketRequest("TestBucket"))

getServiceResponse = client.get_service(ds3.GetServiceRequest())

for bucket in getServiceResponse.result['BucketList']:
    print(bucket['Name'])

Client

In the ds3_python3_sdk there are two ways that you can create a Client instance: environment variables, or manually. ds3.createClientFromEnv will create a Client using the following environment variables:

• DS3_ENDPOINT - The URL to the DS3 Endpoint
• DS3_ACCESS_KEY - The DS3 access key
• DS3_SECRET_KEY - The DS3 secret key
• http_proxy - If set, the Client instance will proxy through this URL

The Client instance can also be created manually in code with:

from ds3 import ds3

client = ds3.Client("endpoint", ds3.Credentials("access_key", "secret_key"))

The proxy URL can be passed in as the named parameter proxy to Client().

Examples Communicating with the BP

An example of using getService and getBucket to list all accessible buckets and objects

HELPERS: Simple way of moving data to/from a file system

There are helper utilities for putting and getting data to a BP. These are designed to simplify the user workflow so that you don't have to worry about BP job management. The helpers will create BP jobs as necessary, and transfer data in parallel to improve performance.

How to move everything:

• An example of putting ALL files in a directory to a BP bucket
• An example of getting ALL objects in a bucket and landing them in a directory

How to move some things:

If you only want to move some items in a directory/bucket, you can specify them individually. These examples show how to put and get a specific file, but the principle can be expanded to transferring multiple items at once.

• An example of putting ONE file to a BP bucket
• An example of getting ONE object in a bucket

Moving data the old way

To put data to a Spectra S3 appliance you have to do it inside the context of what is called a Bulk Job. Bulk Jobs allow the Spectra S3 appliance to plan how data should land to cache, and subsequently get written/read to/from tape. The basic flow of every job is:

• Generate the list of objects that will either be sent to or retrieved from Spectra S3
• Send a bulk put/get to Spectra S3 to plan the job
• The job will be split into multiple chunks. An application must then get the available list of chunks that can be processed
• For each chunk that can be processed, sent the object (this step can be done in parallel)
• Repeat getting the list of available chunks until all chunks have been processed

An example of the above using the Python SDK for putting data

An example of getting data with the Python SDK

An example of how give objects on the server a different name than what is on the filesystem, and how to delete objects by folder

Creating a New Release

Update the version of the SDK before creating a new release. The format is <major>.<minor>.<patch>, where the <major>.<minor> numbers must match the version of BP. The <patch> is an incrementing number that increments with each SDK release for a given major/minor release.

The release number is specified in setup.py.