Mosaic & ABSBackend when tiles are public

[jsga]

Hello! ✋🏿

Problem description

Titiler fails to fetch a mosaic.json stored in Azure Blob storage when the mosaic.json and the underlying COG tiles are public. In this case one would not need a key. These are the logs:

(...)
File "/opt/bitnami/python/lib/python3.11/site-packages/cogeo_mosaic/backends/__init__.py", line 40, in MosaicBackend
return ABSBackend(input, *args, **kwargs)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "<attrs generated init cogeo_mosaic.backends.az.ABSBackend>", line 14, in __init__
self.__attrs_post_init__()
File "/opt/bitnami/python/lib/python3.11/site-packages/cogeo_mosaic/backends/az.py", line 41, in __attrs_post_init__
HttpResponseError is not None
AssertionError: 'azure-identity' and 'azure-storage-blob' must be installed to use ABSBackend

I suspect this issue is related to developmentseed/cogeo-mosaic#191, let me know if I should post it in the cogeo-mosaic repository instead.

Expected Output

Titiler should be able to access the mosaic.json when public and no key is needed

[vincentsarago]

AssertionError: 'azure-identity' and 'azure-storage-blob' must be installed to use ABSBackend

azure blob storage for mosaic.json (via ABSBackend) needs optional dependencies: https://github.com/developmentseed/cogeo-mosaic/blob/main/pyproject.toml#L39-L41

you can fix this by installing azure-identity and azure-storage-blob in the environment you're running titiler