azure function request body is null on POST

Question

When I send a request to my azure function I am getting the following exception:

Inner exception System.NullReferenceException handled at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw: at AlidadeUtilities.OnUnzipHttpTriggered+d__0.MoveNext (AlidadeUtilities, Version=1.0.0.0, Culture=neutral, PublicKeyToken=nullAlidadeUtilities, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null: C:\tfs\Corolar\Alidade\AlidadeUtilities\DEV\AlidadeUtilities\OnUnzipHttpTriggered\OnUnzipHttpTriggered.csAlidadeUtilities, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null: 26)

Line 26 of my code is:

var requestBody = new StreamReader(req.Body).ReadToEnd();

The surrounding code is:

public static class OnUnzipHttpTriggered
{
    [FunctionName("OnUnzipHttpTriggered")]
    public static async Task<IActionResult> Run(
        [HttpTrigger(AuthorizationLevel.Function, "post", Route = null)] HttpRequest req,
        ILogger log)
    {
        log.LogInformation("C# HTTP trigger function processed a request.");

        var requestBody = new StreamReader(req.Body).ReadToEnd();
        var data = JsonConvert.DeserializeObject<ZipFileMetaData>(requestBody);
        var storageAccount =
        CloudStorageAccount.Parse(Environment.GetEnvironmentVariable("StorageConnectionString"));

What am I doing wrong?

An example request would be a POST with a JSON body.

How could the req.Body be null?

here's the complete error message:

Microsoft.Azure.WebJobs.Host.FunctionInvocationException:
   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw (System.Private.CoreLib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e)
   at Microsoft.Azure.WebJobs.Host.Executors.FunctionExecutor+<ExecuteWithLoggingAsync>d__17.MoveNext (Microsoft.Azure.WebJobs.Host, Version=3.0.3.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35Microsoft.Azure.WebJobs.Host, Version=3.0.3.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35: C:\projects\azure-webjobs-sdk-rqm4t\src\Microsoft.Azure.WebJobs.Host\Executors\FunctionExecutor.csMicrosoft.Azure.WebJobs.Host, Version=3.0.3.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35: 293)
   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw (System.Private.CoreLib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e)
   at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess (System.Private.CoreLib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e)
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification (System.Private.CoreLib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e)
   at System.Runtime.CompilerServices.TaskAwaiter`1.GetResult (System.Private.CoreLib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e)
   at Microsoft.Azure.WebJobs.Host.Executors.FunctionExecutor+<TryExecuteAsync>d__14.MoveNext (Microsoft.Azure.WebJobs.Host, Version=3.0.3.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35Microsoft.Azure.WebJobs.Host, Version=3.0.3.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35: C:\projects\azure-webjobs-sdk-rqm4t\src\Microsoft.Azure.WebJobs.Host\Executors\FunctionExecutor.csMicrosoft.Azure.WebJobs.Host, Version=3.0.3.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35: 89)
Inner exception System.NullReferenceException handled at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw:
   at AlidadeUtilities.OnUnzipHttpTriggered+<Run>d__0.MoveNext (AlidadeUtilities, Version=1.0.0.0, Culture=neutral, PublicKeyToken=nullAlidadeUtilities, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null: C:\tfs\ccc\Alidade\AlidadeUtilities\DEV\AlidadeUtilities\OnUnzipHttpTriggered\OnUnzipHttpTriggered.csAlidadeUtilities, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null: 26)
   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw (System.Private.CoreLib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e)
   at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess (System.Private.CoreLib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e)
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification (System.Private.CoreLib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e)
   at System.Runtime.CompilerServices.TaskAwaiter`1.GetResult (System.Private.CoreLib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e)
   at Microsoft.Azure.WebJobs.Host.Executors.FunctionInvoker`2+<InvokeAsync>d__9.MoveNext (Microsoft.Azure.WebJobs.Host, Version=3.0.3.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35Microsoft.Azure.WebJobs.Host, Version=3.0.3.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35: C:\projects\azure-webjobs-sdk-rqm4t\src\Microsoft.Azure.WebJobs.Host\Executors\FunctionInvoker.csMicrosoft.Azure.WebJobs.Host, Version=3.0.3.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35: 63)
   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw (System.Private.CoreLib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e)
   at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess (System.Private.CoreLib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e)
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification (System.Private.CoreLib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e)
   at System.Runtime.CompilerServices.TaskAwaiter`1.GetResult (System.Private.CoreLib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e)
   at Microsoft.Azure.WebJobs.Host.Executors.FunctionExecutor+<InvokeAsync>d__25.MoveNext (Microsoft.Azure.WebJobs.Host, Version=3.0.3.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35Microsoft.Azure.WebJobs.Host, Version=3.0.3.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35: C:\projects\azure-webjobs-sdk-rqm4t\src\Microsoft.Azure.WebJobs.Host\Executors\FunctionExecutor.csMicrosoft.Azure.WebJobs.Host, Version=3.0.3.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35: 556)
   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw (System.Private.CoreLib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e)
   at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess (System.Private.CoreLib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e)
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification (System.Private.CoreLib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e)
   at System.Runtime.CompilerServices.TaskAwaiter.GetResult (System.Private.CoreLib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e)
   at Microsoft.Azure.WebJobs.Host.Executors.FunctionExecutor+<ExecuteWithWatchersAsync>d__24.MoveNext (Microsoft.Azure.WebJobs.Host, Version=3.0.3.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35Microsoft.Azure.WebJobs.Host, Version=3.0.3.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35: C:\projects\azure-webjobs-sdk-rqm4t\src\Microsoft.Azure.WebJobs.Host\Executors\FunctionExecutor.csMicrosoft.Azure.WebJobs.Host, Version=3.0.3.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35: 503)
   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw (System.Private.CoreLib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e)
   at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess (System.Private.CoreLib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e)
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification (System.Private.CoreLib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e)
   at System.Runtime.CompilerServices.TaskAwaiter.GetResult (System.Private.CoreLib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e)
   at Microsoft.Azure.WebJobs.Host.Executors.FunctionExecutor+<ExecuteWithLoggingAsync>d__23.MoveNext (Microsoft.Azure.WebJobs.Host, Version=3.0.3.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35Microsoft.Azure.WebJobs.Host, Version=3.0.3.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35: C:\projects\azure-webjobs-sdk-rqm4t\src\Microsoft.Azure.WebJobs.Host\Executors\FunctionExecutor.csMicrosoft.Azure.WebJobs.Host, Version=3.0.3.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35: 439)
   at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw (System.Private.CoreLib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e)
   at System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess (System.Private.CoreLib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e)
   at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification (System.Private.CoreLib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e)
   at System.Runtime.CompilerServices.TaskAwaiter.GetResult (System.Private.CoreLib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=7cec85d7bea7798e)
   at Microsoft.Azure.WebJobs.Host.Executors.FunctionExecutor+<ExecuteWithLoggingAsync>d__17.MoveNext (Microsoft.Azure.WebJobs.Host, Version=3.0.3.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35Microsoft.Azure.WebJobs.Host, Version=3.0.3.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35: C:\projects\azure-webjobs-sdk-rqm4t\src\Microsoft.Azure.WebJobs.Host\Executors\FunctionExecutor.csMicrosoft.Azure.WebJobs.Host, Version=3.0.3.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35: 249)

The function accepts both GET and POST requests. GET request have no BODY. — Nkosi
indeed, but i am making a POST request, yet there's a null reference exception — Alex Gordon
lh3.googleusercontent.com/-HMlKajbIe7g/XCE87SqVBCI/AAAAAAAABOE/… — Alex Gordon
check to make sure that the request in teh trigger is in fact a POST. — Nkosi
@Nkosi thank you. i've redeployed deleting the GET completely, also i've updated the question to include the full error message — Alex Gordon

HariHaran HariHaran · Accepted Answer · 2018-12-26T04:17:40

Firs change the request class to HttpRequestMessage instead of just HttpRequest

The body of the message should be read using

var msg = req.Content.ReadAsStringAsync().Result;

There's no direct req.Body that you are tying to access and so you are getting a null reference exception. If you want the message and messageHeaders then deserialize the msg to and you will have both the values.

  class Content{
    public dynamic MessageBody { get; set; }
    public dynamic MessageHeader { get; set; }
  }
  var message = JsonConvert.DeserializeObject<Content>(msg);
  var messageContext = message.MessageHeader;

You can also see the trigger example in docs

azure function request body is null on POST

1 Answers