Following Microsoft AZ-204 Learning Path, Encountered error "Unhandled exception. System.NotSupportedException: Stream does not support reading."

Question

I am following the AZ-204: Develop solutions that use Blob storage / Work with Azure Blob storage tutorial located here .

The code is copy/paste but I have encountered an error. I am not a .net developer and I have no idea how to resolve this. Microsoft offers no troubleshooting resources with this self-led material. I'm hoping to find help for resolving this error.

The file I am attempting to run:

using Azure.Storage.Blobs;
using Azure.Storage.Blobs.Models;

Console.WriteLine("Azure Blob Storage exercise\n");

// Run the examples asynchronously, wait for the results before proceeding
ProcessAsync().GetAwaiter().GetResult();

Console.WriteLine("Press enter to exit the sample application.");
Console.ReadLine();

static async Task ProcessAsync()
{
    // Copy the connection string from the portal in the variable below.
    string storageConnectionString = "[redacted]";

    // Create a client that can authenticate with a connection string
    BlobServiceClient blobServiceClient = new BlobServiceClient(storageConnectionString);

    // COPY EXAMPLE CODE BELOW HERE
    
    // CREATE A CONTAINER
    //Create a unique name for the container
    string containerName = "wtblob" + Guid.NewGuid().ToString();

    // Create the container and return a container client object
    BlobContainerClient containerClient = await blobServiceClient.CreateBlobContainerAsync(containerName);
    Console.WriteLine("A container named '" + containerName + "' has been created. " +
        "\nTake a minute and verify in the portal." + 
        "\nNext a file will be created and uploaded to the container.");
    Console.WriteLine("Press 'Enter' to continue.");
    Console.ReadLine();
    
    // UPLOAD BLOBS TO A CONTAINER
    // Create a local file in the ./data/ directory for uploading and downloading
    string localPath = "./data/";
    string fileName = "wtfile" + Guid.NewGuid().ToString() + ".txt";
    string localFilePath = Path.Combine(localPath, fileName);

    // Write text to the file
    await File.WriteAllTextAsync(localFilePath, "Hello, World!");

    // Get a reference to the blob
    BlobClient blobClient = containerClient.GetBlobClient(fileName);

    Console.WriteLine("Uploading to Blob storage as blob:\n\t {0}\n", blobClient.Uri);

    // Open the file and upload its data
    using (FileStream uploadFileStream = File.OpenWrite(localFilePath))
        {
    await blobClient.UploadAsync(uploadFileStream);
    uploadFileStream.Close();
        }

    Console.WriteLine("\nThe file was uploaded. We'll verify by listing" + 
            " the blobs next.");
    Console.WriteLine("Press 'Enter' to continue.");
    Console.ReadLine();
    
    // LIST THE BLOBS IN A CONTAINER
    // List blobs in the container
    Console.WriteLine("Listing blobs...");
    await foreach (BlobItem blobItem in containerClient.GetBlobsAsync())
    {
        Console.WriteLine("\t" + blobItem.Name);
    }

    Console.WriteLine("\nYou can also verify by looking inside the " + 
            "container in the portal." +
            "\nNext the blob will be downloaded with an altered file name.");
    Console.WriteLine("Press 'Enter' to continue.");
    Console.ReadLine();
    
    // DOWNLOAD BLOBS
    // Download the blob to a local file
    // Append the string "DOWNLOADED" before the .txt extension 
    string downloadFilePath = localFilePath.Replace(".txt", "DOWNLOADED.txt");

    Console.WriteLine("\nDownloading blob to\n\t{0}\n", downloadFilePath);

    // Download the blob's contents and save it to a file
    BlobDownloadInfo download = await blobClient.DownloadAsync();

    using (FileStream downloadFileStream = File.OpenWrite(downloadFilePath))
    {
        await download.Content.CopyToAsync(downloadFileStream);
    }
    Console.WriteLine("\nLocate the local file in the data directory created earlier to verify it was downloaded.");
    Console.WriteLine("The next step is to delete the container and local files.");
    Console.WriteLine("Press 'Enter' to continue.");
    Console.ReadLine();
    
    // DELETE A CONTAINER
    // Delete the container and clean up local files created
    Console.WriteLine("\n\nDeleting blob container...");
    await containerClient.DeleteAsync();

    Console.WriteLine("Deleting the local source and downloaded files...");
    File.Delete(localFilePath);
    File.Delete(downloadFilePath);

    Console.WriteLine("Finished cleaning up.");
    
    
}

I am able to verify the container was created in the azure portal, then the code runs up to line 46 where "Uploading to Blob storage as blob:" is logged, then encounters the error. The console output (including prior to the error):

Azure Blob Storage exercise

A container named 'wtblob167d9a9b-d4c0-4b2c-9ea3-21d2c90fd386' has been created. 
Take a minute and verify in the portal.
Next a file will be created and uploaded to the container.
Press 'Enter' to continue.

Uploading to Blob storage as blob:
         https://[redacted].blob.core.windows.net/wtblob167d9a9b-d4c0-4b2c-9ea3-21d2c90fd386/wtfilebfbd8b5e-d5b3-487c-885b-364db2fe126a.txt

Unhandled exception. System.NotSupportedException: Stream does not support reading.
   at System.IO.Strategies.BufferedFileStreamStrategy.CopyToAsync(Stream destination, Int32 bufferSize, CancellationToken cancellationToken)
   at System.IO.FileStream.CopyToAsync(Stream destination, Int32 bufferSize, CancellationToken cancellationToken)
   at Azure.Storage.NonDisposingStream.CopyToAsync(Stream destination, Int32 bufferSize, CancellationToken cancellationToken)
   at Azure.Core.RequestContent.StreamContent.WriteToAsync(Stream stream, CancellationToken cancellation)
   at Azure.Core.Pipeline.HttpClientTransport.PipelineRequest.PipelineContentAdapter.SerializeToStreamAsync(Stream stream, TransportContext context, CancellationToken cancellationToken)
   at System.Net.Http.HttpContent.<CopyToAsync>g__WaitAsync|56_0(ValueTask copyTask)
   at System.Net.Http.HttpConnection.SendRequestContentAsync(HttpRequestMessage request, HttpContentWriteStream stream, Boolean async, CancellationToken cancellationToken)
   at System.Net.Http.HttpConnection.SendAsyncCore(HttpRequestMessage request, Boolean async, CancellationToken cancellationToken)
   at System.Net.Http.HttpConnection.SendAsyncCore(HttpRequestMessage request, Boolean async, CancellationToken cancellationToken)
   at System.Net.Http.HttpConnectionPool.SendWithVersionDetectionAndRetryAsync(HttpRequestMessage request, Boolean async, Boolean doRequestAuth, CancellationToken cancellationToken)
   at System.Net.Http.HttpClient.<SendAsync>g__Core|83_0(HttpRequestMessage request, HttpCompletionOption completionOption, CancellationTokenSource cts, Boolean disposeCts, CancellationTokenSource pendingRequestsCts, CancellationToken originalCancellationToken)
   at Azure.Core.Pipeline.HttpClientTransport.ProcessAsync(HttpMessage message, Boolean async)
   at Azure.Core.Pipeline.HttpPipelineTransportPolicy.ProcessAsync(HttpMessage message, ReadOnlyMemory`1 pipeline)
   at Azure.Core.Pipeline.ResponseBodyPolicy.ProcessAsync(HttpMessage message, ReadOnlyMemory`1 pipeline, Boolean async)    
   at Azure.Core.Pipeline.HttpPipelineSynchronousPolicy.<ProcessAsync>g__ProcessAsyncInner|4_0(HttpMessage message, ReadOnlyMemory`1 pipeline)
onary`2 metadata, IDictionary`2 tags, BlobRequestConditions conditions, Nullable`1 accessTier, BlobImmutabilityPolicy immutabilityPolicy, Nullable`1 legalHold, IProgress`1 progressHandler, UploadTransferValidationOptions transferValidationOverride, String operationName, Boolean async, CancellationToken cancellationToken)
   at Azure.Storage.Blobs.Specialized.BlockBlobClient.<>c__DisplayClass64_0.<<GetPartitionedUploaderBehaviors>b__0>d.MoveNext()
--- End of stack trace from previous location ---   at Azure.Storage.PartitionedUploader`2.UploadInternal(Stream content, Nullable`1 expectedContentLength, TServiceSpecificData args, IProgress`1 progressHandler, Boolean async, CancellationToken cancellationToken)   at Azure.Storage.Blobs.BlobClient.StagedUploadInternal(Stream content, BlobUploadOptions options, Boolean async, CancellationToken cancellationToken)
   at Azure.Storage.Blobs.BlobClient.UploadAsync(Stream content)   at Program.<<Main>$>g__ProcessAsync|0_0() in C:\Users\[redacted]\Documents\devops\working with blob storage module\az204-blob\Program.cs:line 51
   at Program.<Main>$(String[] args) in C:\Users\[redacted]\Documents\devops\working with blob storage module\az204-blob\Program.cs:line 7

I copied the code from the tutorial and tried to run it following the given instructions. It starts out fine but throws an error when trying to upload the new file to the blob. I expected the new file to be written to the blob, and the remaining instructions to be executed.

Answer 1

I was able to repro the issue locally with the same code and after doing below changes I was able to upload it successfully:

Old Code:

// Open the file and upload its data

using (FileStream uploadFileStream = File.OpenWrite(localFilePath))
    {
await blobClient.UploadAsync(uploadFileStream);
uploadFileStream.Close();
    }

// Modified Code

FileStream uploadFileStream = File.Open(localFilePath, FileMode.Open);
blobClient.Upload(uploadFileStream);

uploadFileStream.Close();

Let me know if that helps !