OpenXML Excel Local Environment vs AWS Lambda

Question

In the local environment (Windows 7, Kestrel, AspNetCore 2.0) everything works great no errors. However, when I deploy to AWS as a LAMBDA function using API Gateway I get the bellow error.

    [HttpPost]
    [Route("Temp")]
    public IActionResult PostTest(IFormFile file)
    {
        using (SpreadsheetDocument document = SpreadsheetDocument.Open(file.OpenReadStream(), false))
        {
        }
        return Ok();
    }

---

Unknown error responding to request: FileFormatException:
System.IO.FileFormatException: File contains corrupted data.
at System.IO.Packaging.ZipPackage..ctor(Stream s, FileMode packageFileMode, FileAccess packageFileAccess)
at System.IO.Packaging.Package.Open(Stream stream, FileMode packageMode, FileAccess packageAccess)
at DocumentFormat.OpenXml.Packaging.OpenXmlPackage.OpenCore(Stream stream, Boolean readWriteMode)
at DocumentFormat.OpenXml.Packaging.SpreadsheetDocument.Open(Stream stream, Boolean isEditable, OpenSettings openSettings)
at api.Controllers.SKUController.Post2Async(IFormFile file) in \lambda\api\Controllers\SKUController.cs:line 72
at lambda_method(Closure , Object , Object[] )
at Microsoft.Extensions.Internal.ObjectMethodExecutor.Execute(Object target, Object[] parameters)
at Microsoft.AspNetCore.Mvc.Internal.ControllerActionInvoker.<InvokeActionMethodAsync>d__12.MoveNext()

I am able to post the excel just fine to AWS, (And even read it using system io) but the method for SpreedsheetDocument.Open is not working. (Also checked on that I can write a text file to a temp directory that seemed to work also)

1. Microsoft.AspNetCore.All 2.0.3 & NETStandard.Library 2.0.1
2. System.IO.Packaging 4.4.1
3. DocumentFormat.OpenXml 2.8.1

Answer 1

Turns out that the API Gateway was encoding it as base64, it needed to be passed in as binary and not encoded. One thing I forgot to do was also deploy it API Gateway.