foreach Azure.Pageable then throw System.FormatException

Question

I refer to the tutorial to write the code for upload a blob to IoT edge mcr.microsoft.com/azure-blob-storage:latest module to list the blobs inside the container.

            BlobServiceClient blobServiceClient = new BlobServiceClient (connectionString);
            string containerName = "customer01";
            BlobContainerClient containerClient = blobServiceClient.GetBlobContainerClient(containerName);
            string localPath = "./data/";
            string fileName = "quickstart" + Guid.NewGuid ().ToString () + ".txt";
            string localFilePath = Path.Combine (localPath, fileName);

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

            // Get a reference to a 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.OpenRead (localFilePath);
            await blobClient.UploadAsync (uploadFileStream, true);
            uploadFileStream.Close ();

            Console.WriteLine ("Listing blobs...");

            // List all blobs in the container
            await
            foreach (BlobItem blobItem in containerClient.GetBlobsAsync()) {
                Console.WriteLine ("\t" + blobItem.Name);
            }

It throws the "Unhandled exception" when foreach "containerClient.GetBlobsAsync()".

Unhandled exception. System.FormatException: String '' was not recognized as a valid DateTime.
at System.DateTimeParse.Parse(ReadOnlySpan1 s, DateTimeFormatInfo dtfi, DateTimeStyles styles, TimeSpan& offset) at System.DateTimeOffset.Parse(String input, IFormatProvider formatProvider, DateTimeStyles styles) at System.DateTimeOffset.Parse(String input, IFormatProvider formatProvider) at Azure.Storage.Blobs.Models.BlobItemProperties.FromXml(XElement element) at Azure.Storage.Blobs.Models.BlobItem.FromXml(XElement element) at Azure.Storage.Blobs.Models.BlobsFlatSegment.<>c.<FromXml>b__30_0(XElement e) at System.Linq.Enumerable.SelectEnumerableIterator2.ToList()
at System.Linq.Enumerable.ToList[TSource](IEnumerable1 source) at Azure.Storage.Blobs.Models.BlobsFlatSegment.FromXml(XElement element) at Azure.Storage.Blobs.BlobRestClient.Container.ListBlobsFlatSegmentAsync_CreateResponse(ClientDiagnostics clientDiagnostics, Response response) at Azure.Storage.Blobs.BlobRestClient.Container.ListBlobsFlatSegmentAsync(ClientDiagnostics clientDiagnostics, HttpPipeline pipeline, Uri resourceUri, String version, String prefix, String marker, Nullable1 maxresults, IEnumerable1 include, Nullable1 timeout, String requestId, Boolean async, String operationName, CancellationToken cancellationToken)
at Azure.Storage.Blobs.BlobContainerClient.GetBlobsInternal(String marker, BlobTraits traits, BlobStates states, String prefix, Nullable1 pageSizeHint, Boolean async, CancellationToken cancellationToken) at Azure.Storage.Blobs.Models.GetBlobsAsyncCollection.GetNextPageAsync(String continuationToken, Nullable1 pageSizeHint, Boolean async, CancellationToken cancellationToken)
at Azure.Core.Pipeline.TaskExtensions.EnsureCompleted[T](ValueTask1 task) at Azure.Storage.StorageCollectionEnumerator1.StoragePageable.GetEnumerator()+MoveNext()
at BlobStorageV12.Program.Main(String[] args) in D:\projects\code\dotNetCore\VSCode\BlobQuickstartV12_Git\BlobQuickstartV12\Program.cs:line 38
at BlobStorageV12.Program.

• Environment:
  1. Azure.Storage.Blobs 12.4.4
  2. The storage is a module "mcr.microsoft.com/azure-blob-storage:latest" on an Azure Ubuntu VM
  3. The code run on Windows 10, VS Code 1.45.1, .NET Core SDK : Version: 3.1.100 Commit: cd82f021f4

This an XML from GetBlobs() caught through fiddler. The "Creation-Time" is empty.

<?xml version="1.0" encoding="UTF-8"?>
<EnumerationResults ServiceEndpoint="http://my edge device storage url " ContainerName="blobfromappa1f9e394-5bd2-4110-b9c5-9396b4a7477b">
   <Blobs>
      <Blob>
         <Name>myFile8eba48b8-475a-4f32-a8a4-c6866cacd703.txt</Name>
         <Properties>
            <Creation-Time />
            <Last-Modified>Wed, 10 Jun 2020 01:51:53 GMT</Last-Modified>
            <Etag>0x8D80CE0D98F7DF6</Etag>
            <Content-Length>14</Content-Length>
            <Content-Type>application/octet-stream</Content-Type>
            <Content-Encoding />
            <Content-Language />
            <Content-MD5>76PGAUTjS5+W39/uoprDKg==</Content-MD5>
            <Cache-Control />
            <Content-Disposition />
            <BlobType>BlockBlob</BlobType>
            <LeaseStatus>unlocked</LeaseStatus>
            <LeaseState>available</LeaseState>
            <ServerEncrypted>false</ServerEncrypted>
            <TagCount>0</TagCount>
         </Properties>
      </Blob>
   </Blobs>
   <NextMarker />
</EnumerationResults>

Does anyone know why it throws the exception? Is it because I missed some config? Thank you!

Answer 1

Reading the documentation about it here, basically the issue is that IoT edge uses blob storage modules that are consistent with REST API version 2017-04-17.

Blob storage modules on IoT Edge use the Azure Storage SDKs, and are consistent with the 2017-04-17 version of the Azure Storage API for block blob endpoints.

Considering this, you will need to use a SDK version that targets REST API version 2017-04-17. According to this link, that SDK version would be 8.2. You can install that version from here: https://www.nuget.org/packages/WindowsAzure.Storage/8.2.0