Support for ExpiryOptions on BlobStore requests

[JensWalter]

I tried setting the expiry option on some blob store request, but I could not find the appropriate way to do so.

Setting an expiration is described in the official documentation:
https://docs.microsoft.com/en-us/rest/api/storageservices/set-blob-expiry

So far I could not figure out how I could send such options. I tried setting those parameters through the metadata field, but this lead to the following result.

let mut metadata = Metadata::new();
metadata.insert("x-ms-expiry-time".to_string(), "300000".to_string());
metadata.insert("x-ms-expiry-option".to_string(), "RealtiveToCreation".to_string());
let res = container
  .as_blob_client(blob_key)
  .put_block_blob(blob_data.clone())
  .content_type("text/plain")
  .hash(&hash)
  .metadata(&metadata)
  .execute()
  .await.unwrap();

The header was transformed into

  headers: {
    "content-length": "181",
    "x-ms-blob-type": "BlockBlob",
    "content-md5": "cew9Xo2MS8dQ+UyCtsta3w==",
    "content-type": "text/plain",
    "x-ms-meta-x-ms-expiry-option": "RealtiveToCreation",
    "x-ms-meta-x-ms-expiry-time": "300000",
    "x-ms-date": "Fri, 11 Jun 2021 15:23:19 GMT",
    "x-ms-version": "2019-12-12",
    "authorization": "SharedKey ******",
  },

What would be the correct way to set the expiration?
If this feature does not yet exist, what would be the best approach integrating this into the sdk?

[MindFlavor]

Hi @JensWalter, no, the blob expiry is not currently supported by the SDK. The expiry feature is available since version 2020-02-10 but the SDK still targets 2019-12-12 as defined here:

azure-sdk-for-rust/sdk/storage/src/core/clients/storage_account_client.rs

Line 20 in fb5598b

pub(crate) const AZURE_VERSION: &str = "2019-12-12";

The metadata function you are using is related to this feature: set-blob-metadata. This basically attaches arbitrary key-value pairs to a blob. That's why your headers get mangled.

While there is no way to customize the service level nor pass extra headers right now, we are currently migrating to a pipeline-based approach that will be less strict, possibly allowing users to fully customize the headers sent to Azure.

[JensWalter]

OK, thanks for the explanation.
So I will wait for the necessary migrations to happen first.

Let me know when I can help in any way to get this into the SDK.

[bmc-msft]

Support for blob expiry was added in #913