Any way to set access-control-allow-origin for a windows azure blob

Question

I am storing json blobs on azure which I am accessing via XHR. While trying to load these blobs I am getting this error:
XMLHttpRequest cannot load http://myazureaccount.blob.core.windows.net/myjsoncontainer/myblob.json?json. Origin http://localhost is not allowed by Access-Control-Allow-Origin.

Is there any way to set the Access-Control-Allow-Origin header of a blob returned by azure?

Answer 1

Windows Azure Storage added CORS support on November 26, 2013: Cross-Origin Resource Sharing (CORS) Support for the Windows Azure Storage Services. More details and C#/JavaScript samples - Windows Azure Storage: Introducing CORS.

The CORS options can be set on a storage account using the Windows.Azure.Storage client library version 3.0.1.0 or later, available from NuGet, using something similar to the following pseudocode:

var storageAccount = CloudStorageAccount.Parse(
          "DefaultEndpointsProtocol=https;AccountName=ABC;AccountKey=XYZ");
var blobClient = storageAccount.CreateCloudBlobClient();
var serviceProperties = blobClient.GetServiceProperties();

serviceProperties.Cors.CorsRules.Clear();

serviceProperties.Cors.CorsRules.Add(new CorsRule() {
    AllowedHeaders = { "..." },
    AllowedMethods = CorsHttpMethods.Get | CorsHttpMethods.Head,
    AllowedOrigins = { "..." },
    ExposedHeaders = { "..." },
    MaxAgeInSeconds = 600
});

blobClient.SetServiceProperties(serviceProperties);

Answer 2

Not currently but Scott Hanselman, Program Manager for Azure, has confirmed support for this is coming soon on Feb 4th 2013.