Support pod identity for storage authentication

[omerlh]

Is your feature request related to a problem?/Why is this needed

Use pod identity is better from a security point of view compared to regular secrets (SAS or blob access keys). Easier to manage, distribute etc.

Describe the solution you'd like in detail

Add support for authentication to storage with managed identity in addition to SAS/account token.

Describe alternatives you've considered

Additional context

[vbrinza]

+1

[andyzhangx]

if you mean blobfuse driver, we already support read sas token from azure keyvault in blobfuse csi driver:
https://github.com/csi-driver/blobfuse-csi-driver/blob/master/docs/read-from-keyvault.md

[vbrinza]

@andyzhangx I am using the https://github.com/Azure/kubernetes-volume-drivers/tree/master/flexvolume/blobfuse

[andyzhangx]

@andyzhangx I am using the https://github.com/Azure/kubernetes-volume-drivers/tree/master/flexvolume/blobfuse

new features will only be implemented in csi driver

[andyzhangx]

here is the tracking issue in blobfuse csi driver: kubernetes-sigs/blob-csi-driver#109