Azure Blob Storage client library v12 setting proxy

Question

I migrate from v11 to v12 and I want to replace:

var c = new CloudBlobClient(credentiels, delegatingHandler);

to

var c = new BlobServiceClient(uri, credentiels);

The problem is how to pass that the delegatingHandler in v12?

Answer 1

v12 azure.Storage.Blobs class name is different from v11. v12 has no DelegatingHandler parameter in the constructor.

The DelegatingHandler can change the Proxy property of the HttpClientHandler.

• In such scenario, this instance will be unique to the client. If you don't specify a DelegatingHandler, a singleton HttpClientHandler will be used.
• As previously said, we utilise DelegatingHandler, which has the ability to alter Proxy's properties. First, we'll build a DelegatingHandler implementation for that reason.

ProxyInjectionHandler.cs

using System.Net;
using System.Net.Http;
using System.Threading;
using System.Threading.Tasks;

namespace Hoge {
  public class ProxyInjectionHandler: DelegatingHandler {
    private readonly IWebProxy Proxy;
    private bool FirstCall = true;

    public ProxyInjectionHandler(IWebProxy proxy) {
      this.Proxy = proxy;
    }

    protected override Task <HttpResponseMessage> SendAsync(HttpRequestMessage request, CancellationToken cancellationToken) {
      if (FirstCall) {
        var handler = (HttpClientHandler) this.InnerHandler;
        handler.Proxy = this.Proxy;
        handler.UseProxy = true;
        FirstCall = false;
      }
      return base.SendAsync(request, cancellationToken);
    }
  }
}

Pass this to the client's constructor.

var account = CloudStorageAccount.Parse (connectionString);  
var client = new CloudBlobClient (account.BlobEndpoint, account.Credentials, new ProxyInjectionHandler (new WebProxy (new Uri (proxyUrl))));  
var container = client.GetContainerReference ("...");  
await container.CreateIfNotExistsAsync ();

REFERENCES:

• Socket exhaustion when using HttpClient in multiple threads
• Accessing Azure Storage via HTTP Proxy for v12