How access VM file share from Azure Function app

Question

Hi all

I am having VM file share and needs to read files by using Azure function app. All are in same network (app service ) .

I am trying to access file using path \xxxx.xxxx.com\pdf_directory\sample.pdf" and trying to the get the file size

FileInfo fileInfo = new FileInfo(filename);
fileLength = fileInfo.Length;

It gives error "unauthorized access when accessing file". Still I couldn't find any reason for that. Let me know how to resolve this issue ?

Thanks
Nuwan

Answer 1

Hi @Nuwan Wickramanayaka

Thank you for asking this question on the **Microsoft Q&A Platform. **

Assuming that the Azure Function is in the same virtual network as the VM (If not check this documentation https://learn.microsoft.com/en-us/azure/azure-functions/functions-create-vnet)

The reason is that the Function App does not have permission to access the VM,

A way to authenticate is via Automation Account https://serverfault.com/questions/893506/how-to-log-in-to-azure-vm-automatically-from-azure-function

Depending on the language that you are using in your Function you can authenticate in your VM in diverse ways

Hope this helps!

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Answer 2

Hi @Nuwan Wickramanayaka

your question seems to have elements similar to this question on accessing on premise file shares from an Azure Function App. @ajkuma 's answer there indicates that the Sandbox environment restricts outgoing SMB ports.

In a similar question and answer @ChaitanyaNaykodi-MSFT suggests using a logic app to handle interactions with the file share and connecting the logic app to the function app. The extra logic app may not be the most elegant solution, but it will be an effective and supported means to get the results you need .