[FEATURE REQ] Make the process of using a CustomerProvidedKey with BlobClient more DI-friendly

Library or service name. Azure.Storage.Blobs

Is your feature request related to a problem? Please describe. Currently, the process of setting up a BlobClient instance to use a CustomerProvidedKey in projects that leverage DI (e.g., and ASP.NET Core project) is very annoying.

You can inject BlobServiceClient via DI, and obviously you can create BlobContainerClients and BlobClients using the injected BlobServiceClient instance. That’s great for normal usage…but as soon as I need to create a BlobClient that uses a CustomerProvidedKey, it becomes frustrating, because:

• CustomerProvidedKey must be passed via BlobClientOptions
• The only way to pass BlobClientOptions to BlobClient is via its constructors, there’s no other way via the “normal” BlobServiceClient -> BlobContainerClient -> BlobClient route.
• To make things even more annoying, there’s nothing I can “get” from the injected BlobServiceClient and pass to the BlobClient constructor to let me “inherit” the identity, URI, etc in that fashion.

So what you end up with is a situation where your DI-injected BlobServiceClient becomes useless, and you have to inject all of the information needed to set up a brand new BlobClient instance using IOptions<Foo> (or something similar).

For my specific use-case, we generate new encryption keys for each new blob we upload, so I’ve basically ended up creating a BlobClient factory and inject that via DI, but it would really be preferable if there were some way to just create the BlobClient via BlobServiceClient I’m already injecting for other reasons.

If there were an extra overload of BlobContainerClient.GetBlobClient() that took a second parameter of type BlobClientOptions (or perhaps simply CustomerProvidedKey), that would be excellent.

[seanmcc-msft]

@tg-msft, just want to double check, we are cool with:

• BlobServiceClient.WithCustomerProvidedKey(CustomerProvidedKey customerProvidedKey)
• BlobContainerClient.WithCustomerProvidedKey(CustomerProvidedKey customerProvidedKey)
• BlobBaseClient.WithCustomerProvidedKey(CustomerProvidedKey customerProvidedKey)

We could also consider adding WithEncryptionScope(), since the idea is essentially the same.

[seanmcc-msft]

Ok, I will work on this this week.