How to Upload Image From Asp.net Core IFormFile to Azure Blob Storage?

Question

I am trying to upload an image to azure blob storage. However when I look at the end result on azure and it just creates an empty file.

   [HttpPost("Import")]
        public IActionResult Import(IFormFile filepond)
        {
            const string accountName = "accountName";
            const string key = "key14881851";

            var storageAccount = new CloudStorageAccount(new StorageCredentials(accountName, key), true);
            var blobClient = storageAccount.CreateCloudBlobClient();
            var container = blobClient.GetContainerReference("mycontainer");
            container.CreateIfNotExistsAsync();
            container.SetPermissionsAsync(new BlobContainerPermissions()
            {
                PublicAccess = BlobContainerPublicAccessType.Blob
            });

            var blob = container.GetAppendBlobReference("test.jpg");
            blob.UploadFromStreamAsync(filepond.OpenReadStream());

            return Ok();
        }

Some questions (other than why I am getting an empty file).

1. I see alot of these methods are Async, do I need to await them for everything to work properly(ie if the container does not exist that it gets created before a file is written to the container)
2. Do I need to wrap the UploadFromStreamAsync in a using statement.

Answer 1

...do I need to await them for everything to work properly(ie if the container does not exist that it gets created before a file is written to the container)

Yes. Async methods return a task and you have to wait until this task is completed. That's why your file is emty.

Do I need to wrap the UploadFromStreamAsync in a using statement.

I would call it cleaner, while I'n not sure if it absolutely necessary here.

I would write it like so (not tested):

        var blobClient = storageAccount.CreateCloudBlobClient();
        var container = blobClient.GetContainerReference("mycontainer");
        await container.CreateIfNotExistsAsync();
        container.SetPermissionsAsync(new BlobContainerPermissions()
        {
            PublicAccess = BlobContainerPublicAccessType.Blob
        });

        var blob = container.GetBlockBlobReference("test.jpg");
        using(var stream = filepond.OpenReadStream()) {
            await blob.UploadFromStreamAsync(stream);
        }

Please note, that I replaced GetAppendBlobReference() with GetBlockBlobReference().

Docs with examples https://docs.microsoft.com/en-us/azure/storage/blobs/storage-quickstart-blobs-dotnet?tabs=windows