Azure Functions - Blob Stream output binding
<p>I've created an Azure function with a blob storage trigger - I want to process a file and then dump the file out to another blob storage container.</p>

<p>In the simplest case I suppose it would look like this:</p>

<pre><code>public static void Run(Stream blob, string name, out Stream outputBlob, TraceWriter log)
{
    outputBlob = blob;
}
</code></pre>

<p>These are my bindings:</p>

<pre><code>{
  "bindings": [
    {
      "name": "blob",
      "type": "blobTrigger",
      "direction": "in",
      "path": "input/{name}",
      "connection": "wlimportstaging_STORAGE"
    },
    {
      "name": "outputBlob",
      "type": "blob",
      "direction": "out",
      "path": "original/{name}",
      "connection": "wlimportstaging_STORAGE"
    }
  ],
  "disabled": false
}
</code></pre>

<p>I've read from the documentation that if you return a POCO it will serialize it as JSON.</p>

<p><a href="https://docs.microsoft.com/en-us/azure/azure-functions/functions-bindings-storage-blob#output-usage" rel="nofollow noreferrer">https://docs.microsoft.com/en-us/azure/azure-functions/functions-bindings-storage-blob#output-usage</a></p>

<p>This seems to suggest you can output to a stream - I just seem to be getting: </p>

<p><code>Microsoft.Azure.WebJobs.Host: Can't bind Blob to type 'System.IO.Stream&amp;</code></p>

<p>Please assist!</p>