This change adds a new cloud remote based on Azure Blob Storage [1] and
the azure-storage-blob SDK [2].
The implementation closely follows the patterns laid out by the existing
cloud remotes (AWS and GCP). Notable differences include:
- No use of a lock in the progress-bar callback and no requirement to
look up total transfer size ahead of time: the Azure Storage SDK
provides the total transfer bytes and current transfer offset in its
progress callback.
- When `exists` is called, check the existence of every blob instead of
listing the entire container. Container list operations can be
expensive so unless the number of checked files is very large, making
separate requests is likely going to be more efficient.
- For increased flexibility, access credentials for the Azure Storage
backend can be provided either connection-string style via the remote
URL or via environment variables. The Azure Storage backend can be
emulated via Azurite [3].
[1] https://azure.microsoft.com/en-us/services/storage/blobs/
[2] https://github.com/Azure/azure-storage-python
[3] https://github.com/Azure/azurite
This change was created together with @EricSchles.
Clemens Wolff
Ivan Shcheklein
Ruslan Kuprieiev