support az cli config ~/.azure/config

[efiop]

We currently support env vars, but we should also support azure config file

adlfs/adlfs/spec.py

Lines 251 to 253 in 55ba981

	self.sas_token = sas_token or os.getenv("AZURE_STORAGE_SAS_TOKEN")
	self.client_id = client_id or os.getenv("AZURE_STORAGE_CLIENT_ID")
	self.client_secret = client_secret or os.getenv("AZURE_STORAGE_CLIENT_SECRET")

The way to do it is through knack, we currently do it ourselves in dvc:

https://github.com/iterative/dvc-azure/blob/906cdc22e7d44c027060e49aa94cddbec8e3a8cc/dvc_azure/__init__.py#L26

but it would be really nice and generally useful to have it in adlfs. It should be a simple drop-in replacement for the getenv calls that we have.

This is also similar to how s3fs supports aws config, so seems to be logical to support it in adlfs.

[efiop]

Actually looking at s3fs, I don't see it parsing aws config and I see that we do that explicitly in dvc-s3. I'll close this for now.