Connecting to azurite using a hostname fails

Question

UPDATE: I can verify this behavior is fixed in Azure.Storage.Blobs 12.5.1 https://www.nuget.org/packages/Azure.Storage.Blobs https://github.com/Azure/azure-sdk-for-net/issues/9404

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How can I connect to azurite using a hostname?

I'm trying to emulate Azure Blob Storage in docker using Azurite for integration tests.

All works well, to the point I have to access Azurite via a hostname (which is AFAIK required for docker networking)

My connection string looks like this (which is the default well-known connection string):

"AccountName=devstoreaccount1;AccountKey=Eby8vdM02xNOcqFlqUwJPLlmEtlCDXJ1OUzFT50uSRZ6IFsuFq2UVErCz4I6tq/K1SZFPTOtr/KBHBeksoGMGw==;DefaultEndpointsProtocol=http;BlobEndpoint=http://azurite:10000/devstoreaccount1;"

My docker compose part for azurite looks like this:

services:
  azurite:
    image: mcr.microsoft.com/azure-storage/azurite
    hostname: azurite
    command: "azurite-blob --loose --blobHost 0.0.0.0"
    ports:
      - "10000:10000"
    volumes:
      - ./test/azurite:/data
    networks:
      - stillsnet

  images:
    container_name: images
    image: myapp/images
    build:
      context: .
      dockerfile: Dockerfile
    ports:
       - "5000:5000"
       - "5001:5001"
    environment:
      - ASPNETCORE_ENVIRONMENT=Test
      - ASPNETCORE_URLS=http://+:5000
      - imagesStorage__AzureBlobStorage__ConnectionString=AccountName=devstoreaccount1;DefaultEndpointsProtocol=http;AccountKey=Eby8vdM02xNOcqFlqUwJPLlmEtlCDXJ1OUzFT50uSRZ6IFsuFq2UVErCz4I6tq/K1SZFPTOtr/KBHBeksoGMGw==;BlobEndpoint=http://azurite:10000;
    depends_on:
      - azurite
    links:
      - azurite
    networks:
      - stilssnet

my code looks like this:

private const string ConnectionString ="AccountName=devstoreaccount1;AccountKey=Eby8vdM02xNOcqFlqUwJPLlmEtlCDXJ1OUzFT50uSRZ6IFsuFq2UVErCz4I6tq/K1SZFPTOtr/KBHBeksoGMGw==;DefaultEndpointsProtocol=http;BlobEndpoint=http://azurite:10000/devstoreaccount1;";

[Fact]
public async Task UploadFile()
{
   var container = new BlobContainerClient(ConnectionString, "images");
   await using var stream = File.OpenRead(@"C:\temp\output\3ee9bc41-40ea-4d05-b180-e74bd5065622\images\00000000.jpg");
   await container.UploadBlobAsync("test.jpg", stream);
}

this will throw an exception:

System.Xml.XmlException : Root element is missing.
   at System.Xml.XmlTextReaderImpl.Throw(Exception e)
   at System.Xml.XmlTextReaderImpl.ParseDocumentContent()
   at System.Xml.XmlTextReaderImpl.Read()
   at System.Xml.Linq.XDocument.Load(XmlReader reader, LoadOptions options)
   at System.Xml.Linq.XDocument.Load(Stream stream, LoadOptions options)
   at Azure.Storage.Blobs.BlobRestClient.Container.CreateAsync_CreateResponse(Response response)
   at Azure.Storage.Blobs.BlobRestClient.Container.CreateAsync(ClientDiagnostics clientDiagnostics, HttpPipeline pipeline, Uri resourceUri, PublicAccessType access, Nullable`1 timeout, IDictionary`2 metadata, String requestId, Boolean async, String operationName, CancellationToken cancellationToken)
   at Azure.Storage.Blobs.BlobContainerClient.CreateInternal(PublicAccessType publicAccessType, IDictionary`2 metadata, Boolean async, CancellationToken cancellationToken, String operationName)
   at Azure.Storage.Blobs.BlobContainerClient.CreateIfNotExistsInternal(PublicAccessType publicAccessType, IDictionary`2 metadata, Boolean async, CancellationToken cancellationToken)
   at Azure.Storage.Blobs.BlobContainerClient.CreateIfNotExistsAsync(PublicAccessType publicAccessType, IDictionary`2 metadata, CancellationToken cancellationToken)

If I change the connection string from azurite to 127.0.0.1 it all works fine.

Answer 1

The host's name in that network is azurite, so you can use this connection string UseDevelopmentStorage=true;DevelopmentStorageProxyUri=http://azurite.

Works for me and I think is the way to do it.

Also you can use the legacy storage emulator (that includes Tables), instead of azurite you put docker.host.internal

Answer 2

UPDATE: I can verify this behavior is fixed in Azure.Storage.Blobs 12.5.1 https://www.nuget.org/packages/Azure.Storage.Blobs https://github.com/Azure/azure-sdk-for-net/issues/9404

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It looks like the BlobContainerClient itself strips away the account name from the URL if you use anything else than localhost or an IP address, so the client generates this:

PUT /images?restype=container HTTP/1.1" 400 - instead of PUT /devstoreaccount1/images?restype=container HTTP/1.1 201

As an ugly workaround we can include the account name in the container name when testing against azurite: var container = new BlobContainerClient(ConnectionString, "devstoreaccount1/images");

Though await container.CreateIfNotExistsAsync(); doesn't work properly against azurite then (throws a 409 Exception when it already exist...

So we either have:

• an ugly hack
• dropping azurite in favor of a real blob storage account
• dropping the BlobContainerClient which seems to perform too much magic based on the host name.

It doesn't seem to be related to Azurite itself, or ideally it should support root URL's that are compatible with the Azure blob store without having to specify the account name prefix.