How to use an Azure blob-only storage account with Azure Functions - Trying to create blob snapshot

Question

I'm trying to set up a function to take a snapshot of a blob container every time a change is pushed to it. There is some pretty simple functionality in Azure Functions to do this, but it only works for general purpose storage accounts. I'm trying to do this with a blob only storage account. I'm very new to Azure so I may be approaching this all wrong, but I haven't been able to find much helpful information. Is there any way to do this?

Please edit your question and include more details. For example, include the code to take snapshot. What happens when you try to take a snapshot for blobs in blob storage account? Are you getting any error? In its current state, there's not much information available in the question to provide meaningful solution. — Gaurav Mantri
You mean you have a blobtrigger function ? If so you need to understand that Azure functions needs a storage account because it uses storage table to persist data. This is configured using AzureWebJobsStorage and AzureWebJobsDashboard but you can configure your blobtrigger function to use a different connectionstring. Does it make sense for you ? Would you like some code sample ? — Thomas
Yes it is a blob trigger. How would I go about making the function use a different connection string? According to Microsoft documentation the storage account would have to be general purpose to connect to the function trigger. In the UI my storage container is never an option. — L. Hanson

Thomas Thomas · Accepted Answer · 2018-05-09T01:24:02

As @joy-wang mentioned, the Azure Functions Runtime requires a general purpose storage account.

A general purpose storage account is required to configure the AzureWebJobsStorage and the AzureWebJobsDashboard settings (local.settings.json or Appsettings Blade in the Azure portal):

{
  "IsEncrypted": false,
  "Values": {
    "AzureWebJobsStorage": "my general purpose storage account connection string",
    "AzureWebJobsDashboard": "my general purpose storage account connection string",
    "MyOtherStorageAccountConnectionstring": "my blob only storage connection string"
  }
}

If you want to create a BlobTrigger Function, you can specify another connection string and create a snapshot everytime a blob is created/updated:

[FunctionName("Function1")]
public static async Task Run([BlobTrigger("test-container/{name}",
        Connection = "MyOtherStorageAccountConnectionstring")]CloudBlockBlob myBlob,
        string name, TraceWriter log)
{
    log.Info($"C# Blob trigger function Processed blob\n Name:{name}");
    await myBlob.CreateSnapshotAsync();
}

How to use an Azure blob-only storage account with Azure Functions - Trying to create blob snapshot

2 Answers