Azure Blob Storage, Upload Large Blob

Question

I am trying to upload a large blob into Azure blob storage but getting exception

System.NotSupportedException: 'Specified method is not supported.'

.NET 9, function app hosted on app service plan.

My code is

[Function("uploadExtratcs")]
public async Task<IActionResult> Run([HttpTrigger(AuthorizationLevel.Function, "post", 
Route = "extracts/{systemName}/{extractType}")] HttpRequest req
, string systemName, string extractType)
{
try
{
    logger.LogInformation($"Uploading blob {systemName} of type {extractType} has started.");

    BlobContainerClient containerClient = blobServiceClient.GetBlobContainerClient("test");
    BlockBlobClient blockBlobClient = containerClient.GetBlockBlobClient("test.csv");
    int blockSize = 1 * 1024 * 1024;//1 MB Block
    int offset = 0;
    int counter = 0;
    List<string> blockIds = new List<string>();

    var bytesRemaining = req.Body.Length;  **// Error in thrown on this line**
    do
    {
        var dataToRead = Math.Min(bytesRemaining, blockSize);
        byte[] data = new byte[dataToRead];
        var dataRead = req.Body.Read(data, offset, (int)dataToRead);
        bytesRemaining -= dataRead;
        if (dataRead > 0)
        {
            var blockId = Convert.ToBase64String(Encoding.UTF8.GetBytes(counter.ToString("d6")));
            await blockBlobClient.StageBlockAsync(blockId, new MemoryStream(data));
            logger.LogInformation(string.Format("Block {0} uploaded successfully.", counter.ToString("d6")));
            blockIds.Add(blockId);
            counter++;
        }
    }
    while (bytesRemaining > 0);
    var headers = new BlobHttpHeaders()
    {
        ContentType = "application/octet-stream"
    };
    Response<BlobContentInfo> response = await blockBlobClient.CommitBlockListAsync(blockIds, headers);


    await blobStorageService.UploadBlob("pvdb-extracts", $"{systemName}/{extractType}.csv", req.Body);
    logger.LogInformation("Uploading blob has finished.");

    return new OkObjectResult(new { message = "upload successfully" });
}
catch (System.Exception ex)
{
    logger.LogError(ex, "Error uploading file");
    throw;
}
}

Update 1: I have made some changes in the code and now I am getting this error

Microsoft.AspNetCore.Server.Kestrel.Core.BadHttpRequestException: 'Request body too large. The max request body size is 30000000 bytes.'

on line

dataRead = await req.Body.ReadAsync(data, offset, dataToRead);

So look like the blob stream I am passing to the function app is quite large and that limit needs to be changed somewhere. I did not get that error on a smaller stream.

Update 2:

I have increased the limit and looks like I don't need to splint request body into chunks and it works with the standard SDK method

services.Configure<KestrelServerOptions>(options =>
{
options.Limits.MaxRequestBodySize = 300000000;
});

and now I can use following SDK method to upload the whole stream

Response<BlobContentInfo> response = await 
blobClient.UploadAsync(blobContent, true);

Looks like there is no need to split into chunks at least in my case.

Update 3:

I am able to test is locally after setting the paylaod size to 300mb but when I deploy I am getting folowig error:

Exception while executing function: Functions.uploadExtratcs Exception binding parameter 'req' Request body too large. The max request body size is 100 bytes.