fsspec
Make AzureBlobFileSystem anon behaviour configurable via env var.
Making the anon default value configurable from an env var makes integration easier with helm charts that provide features like RBAC in Azure accounts.
In a multi-cloud application I am working on it is impacting that the code needs to change between AWS and Azure. The default in s3fs is anon=False, in adlfs anon=True.
This PR would allow for configuration only to change without any code change.
It would facilitate integration with https://azure.github.io/azure-workload-identity/docs/quick-start.html without any code change apart from environment variables.
Are you able to add a test and docs?
I think pytest has a fixture to monkeypatch environment variables for a test. Just need to confirm that it gets set in __init__ properly.
Checking in here, will you have a chance to update these last things @microft?
Will try to update in the next few days. (Festivities plus child birth have kept me mostly offline)
@TomAugspurger I got a test going, but the cachable property (inherited from AbstractFileSystem) seems to complicate testing multiple instances with the same account_name and connection_string. Hence the monkey patch on cachable for that test.
Hope it makes sense.
@TomAugspurger: Any idea when this can be approved and merged, please? It's affecting us badly, too.
