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dariemcarlosdev / VPKFILEPROCESSORAPP

Blazor Server app that takes a CSV file as input, runs a background job to execute an SSIS package in Azure, and stores the output CSV file in Azure Blob Storage for download.
GNU Affero General Public License v3.0
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Issue: Object reference not set to an instance of an object #34

Closed dariemcarlosdev closed 2 weeks ago

dariemcarlosdev commented 2 weeks ago

After resolve the type mismatch issue and enable a compatible binding for blob operations, another issue came up.

Bug Description::Object reference not set to an instance of an object

The error indicates a NullReferenceException, which usually means that one of the objects I am trying to access hasn’t been properly instantiated. Given that the function is detecting the blob (downloads/input.csv) but then throws this exception:

Solution:

1. Check BlobClient Initialization and Connection.

2. Inspect Environment Configuration. I made sure that ContainerBlobStorage connection string is correctly configured and accessible in AZ Func Environment valiables settings. If it’s missing or incorrect, the BlobServiceClient may not be able to establish a connection, leading to null references in the function.

3. Validate Permissions for Managed Identity. Since you're using a User-Assigned Managed Identity for accessing Azure Blob Storage in your function, here are some additional areas I have to verify:

  • Ensure Correct Identity Assignment: Verify that your function app is configured to use the correct User-Assigned Managed Identity.

Go to your Function App > Identity section. Check under the User-assigned tab to confirm that the appropriate identity is assigned.

  • Verify Role Assignment for Managed Identity: Make sure that the User-Assigned Managed Identity has Storage BlobData Contributor, or Owner role on the Blob Storage account. These roles provides both read and write access. In this project the Role assigned is Owner on the Blob Storage account, which is an inhetired Role assigned from the Resouce Group Scope.

Go to the Blob Storage account in the Azure Portal. Under Access Control (IAM), ensure the managed identity is listed withOwner permissions on either the entire storage account or the specific blob container.

  1. I created a separate Enviroment Variable(EV) named ContainerBlobSotage for holding the conection string to Storage Account, which is used in AZ function as a binding parameter. The conection string previusly was stored in AzureWebJobsStorage EV, now this one just hold the as value the connection string to azfuncblobtriggernotify Storage Account, which is a linked Azure Storage account, which is used to store data that your function needs to access, like temporary files or queue messages, unless you explicitly choose to use an existing storage account during the creation process.

Originally posted by @dariemcarlosdev in #32