Azure

Note

Install with pip install labox[azure]

Blob Storage

The BlobStorage provides a storage implementation backed by Azure Blob Storage using the BlobServiceClient client.

A minimal setup for the BlobStorage requires a blob service client and a "router" function that tells the storage in what container and under what path each piece of content should be saved:

from azure.storage.blob.aio import BlobServiceClient

from labox.extra.azure import BlobStorage
from labox.extra.azure import simple_blob_router

blob_storage = BlobStorage(
    service_client=BlobServiceClient(
        account_url="https://myaccount.blob.core.windows.net", credential="<your-credential>"
    ),
    blob_router=simple_blob_router("my-container"),
)

The simple_blob_router requires a container name and an optional prefix that blobs should be added under. If no blob_router is provided the storage becomes read-only and attempts to write to it will produce a NotImplementedError.

Blob Router

A BlobRouter is a function that returns a BlobPointer dict given:

• a digest
• a tag map
• and a temp flag indicating whether the content being written will be deleted after use (this happens for streaming uploads).

The simple_blob_router creates paths of the form:

{prefix}/{content_hash}{ext}

Where:

• prefix is the optionally provided path prefix
• content_hash comes from the Digest passed to the router function
• ext is the file extension inferred from the content_type within the Digest

In the case the temp flag is true simple_blob_router creates a path of the form:

temp/{uuid}{ext}

Where uuid is a uuid4 hex string.

Blob Streamed Uploads

When data is being streamed to a BlobStorage, the content is first uploaded to a temporary location within the container. Since the hash of the content is not known upfront, a temporary location is requested from the storage's router by passing it temp=True. When the upload is complete a final location is requested from the router without the temp flag. The data is then copied from the temporary location to the final location using Azure's server-side copy operation, and the temporary blob is deleted.