Azure Function to duplicate file triggered by upload

Question

I'm trying to extend on the basic tutorial that allows you to log information after a file is uploaded to blob storage. The code from the tutorial works, and was pulled from here:

https://docs.microsoft.com/en-us/azure/azure-functions/functions-create-storage-blob-triggered-function

I am now trying to add an output that makes a copy of that file to another container. I am using code found in an output example found here:

https://docs.microsoft.com/en-us/azure/azure-functions/functions-bindings-storage-blob-output?tabs=csharp#example

My code is just a small add on to the original example.

run.csx:

using System.IO;
using System.Collections.Generic;
using Microsoft.Azure.WebJobs;

public static void Run([BlobTrigger("samples-workitems/{name}")] Stream myBlob, [Blob("copytwotkelly/{name}", FileAccess.Write)] Stream duplicateUpload, string name, ILogger log)
{
    log.LogInformation($"C# Blob trigger function Processed blob\n Name:{name} \n Size: {myBlob.Length} Bytes");

    myBlob.CopyTo(duplicateUpload);
}

function.json:

{
  "bindings": [
    {
      "name": "myBlob",
      "type": "blobTrigger",
      "direction": "in",
      "path": "samples-workitems/{name}",
      "connection": "AzureWebJobsStorage"
    },
    {
      "name": "duplicateUpload",
      "path": "copytwotkelly/{name}",
      "connection": "AzureWebJobsStorage",
      "direction": "out",
      "type": "blob"
    }
  ]
}

When the function triggers I get the error messages:

2020-11-25T06:29:57.518 [Error] run.csx(5,25): error CS0246: The type or namespace name 'BlobTriggerAttribute' could not be found (are you missing a using directive or an assembly reference?) 2020-11-25T06:29:57.580 [Error] run.csx(5,25): error CS0246: The type or namespace name 'BlobTrigger' could not be found (are you missing a using directive or an assembly reference?) 2020-11-25T06:29:57.672 [Error] run.csx(5,82): error CS0246: The type or namespace name 'BlobAttribute' could not be found (are you missing a using directive or an assembly reference?) 2020-11-25T06:29:57.729 [Error] run.csx(5,82): error CS0246: The type or namespace name 'Blob' could not be found (are you missing a using directive or an assembly reference?)

but as far as I can tell, I have followed the configuration directions from the tutorial properly. It doesn't actually show the .json file in the example so I'm not sure what I'm doing wrong. What am I missing? Aren't these classes it's asking for in using Microsoft.Azure.WebJobs; that I referenced? Thanks in advance for any help.

Do you mean that I need to include another namespace? If so which one? The examples don't use any others. — funny_reference_to_something
run.csx is in the wrong format? As far as I can tell it is the same format as the second link I posted. Can you tell me what exactly is wrong with it? — funny_reference_to_something
You can have a check of this: docs.microsoft.com/en-us/azure/azure-functions/… And you can have a try of the answer I post. — Bowman Zhu

Bowman Zhu Bowman Zhu · Accepted Answer · 2020-11-25T07:41:57

Below code works fine on my side:

function.json

{
  "bindings": [
    {
      "name": "myBlob",
      "type": "blobTrigger",
      "direction": "in",
      "path": "test1/{name}",
      "connection": "AzureWebJobsStorage"
    },
    {
      "name": "myOutputBlob",
      "type": "blob",
      "path": "test2/{name}",
      "connection": "AzureWebJobsStorage",
      "direction": "out"
    }
  ]
}

run.csx

public static void Run(Stream myBlob,Stream myOutputBlob, string name, ILogger log)
{
    log.LogInformation($"C# Blob trigger function Processed blob\n Name:{name} \n Size: {myBlob.Length} Bytes");
    myBlob.CopyTo(myOutputBlob);
}

This is the offcial doc:

https://docs.microsoft.com/en-us/azure/azure-functions/functions-bindings-storage-blob-output?tabs=csharp-script#example

Azure Function to duplicate file triggered by upload

1 Answers