Azure Functions: how to to Access Blob Storage with Managed Identity and Getting 403 Forbidden scenarios
I'm trying to figure out I'm confused about I've been banging my head against this for hours. I'm currently working on an Azure Function that needs to read files from an Azure Blob Storage account using a Managed Identity for authentication. I've set up the Managed Identity for my Function App and granted it the 'Reader' role on the Blob Storage account, but when I attempt to access the blob, I keep receiving a 403 Forbidden behavior. Here’s a simplified version of the code I'm using in my Azure Function: ```csharp using System; using System.IO; using System.Threading.Tasks; using Microsoft.AspNetCore.Mvc; using Microsoft.Azure.WebJobs; using Microsoft.Azure.WebJobs.Extensions.Http; using Microsoft.AspNetCore.Http; using Microsoft.Extensions.Logging; using Azure.Storage.Blobs; using Azure.Identity; public static class GetBlobFunction { [FunctionName("GetBlob")] public static async Task<IActionResult> Run( [HttpTrigger(AuthorizationLevel.Function, "get", Route = null)] HttpRequest req, ILogger log) { string blobName = req.Query["blobname"]; string connectionString = Environment.GetEnvironmentVariable("AzureWebJobsStorage"); var blobServiceClient = new BlobServiceClient(new Uri(connectionString), new DefaultAzureCredential()); var containerClient = blobServiceClient.GetBlobContainerClient("my-container"); var blobClient = containerClient.GetBlobClient(blobName); try { var response = await blobClient.DownloadAsync(); using (var streamReader = new StreamReader(response.Value.Content)) { string content = await streamReader.ReadToEndAsync(); return new OkObjectResult(content); } } catch (Exception ex) { log.LogError(ex, "behavior accessing blob: {BlobName}", blobName); return new StatusCodeResult(500); } } } ``` I've also ensured that the environment variable `AzureWebJobsStorage` is correctly set to the storage account connection string. However, I still get this behavior: ``` Azure.RequestFailedException: Request failed with status code 403 (Forbidden) ``` I've also tried adding the Storage Blob Data Contributor role to the Managed Identity, but the behavior continues. Can anyone guide to diagnose what might be going wrong here? Are there any additional steps I need to take to properly configure the access? My development environment is Linux. Has anyone else encountered this? I recently upgraded to C# 3.11. Could this be a known issue? Any suggestions would be helpful.