Is there an Azure blob matadata autofill functionality?

Question

I have a blob container that contains multiple folders in it, and I'm using a Search Service to index and then query that data. I want to apply a filter on my search to only be able to retrieve the files in a specific folder in the blob. Is there a way to do that?

I have tried manually setting a new metadata field (let's call it folder_name) and set the value in it to the name of the folder containing the data file I'm targetting and it worked. However, I need a more automated way to do this.

Is there a way to automatically fill a file's metadata field with the name of the folder containing this file through the Azure portal? I basically want any file that gets uploaded to a folder on the blob to have a metadata field filled with its folder name automatically upon upload.

Here's an example flow:

• The file is uploaded on Azure blob container inside a specific folder (for example "reports")
• the metadata of the file is then edited so that a new metadata field called "folder_name" is created and has the value "reports" assigned.

If that's possible through the portal please let me know, if not but it's possible in C# that would also be helpful. And if there's an easier workaround for the search filtering that would also be great!

Answer 1

@S-A Thank you for the great answer from @Luke Murray . I am going to expand upon their answer a little further.

Yes, it is possible to automatically fill a file's metadata field with the name of the folder containing the file through the Azure portal. You can use Azure Blob Storage triggers to achieve this.

Here's how you can do it:

1. Create a new Azure Function App in the Azure portal.
2. Add a new Blob trigger to the function app. This will allow the function to be triggered whenever a new blob is added to the container.
3. In the function code, you can use the blob's path to extract the folder name and then update the blob's metadata with the folder name.
4. Save and publish the function.

Once the function is published, it will be triggered whenever a new blob is added to the container. The function will extract the folder name from the blob's path and update the blob's metadata with the folder name.

Regarding your search filtering requirement, you can use the "metadata_storage_path" field to filter the search results based on the folder name. For example, if you want to retrieve all the blobs in the "reports" folder, you can use the following filter expression:

search=*&$filter=metadata_storage_path eq '/reports/'

This will retrieve all the blobs in the "reports" folder. You can modify the filter expression to retrieve blobs from other folders as well.

Answer 2

To use the Portal, you would have to recreate the index, as part of the index creation, it asks what Blob Folder to use.

You can edit the JSON file however for an index already existing: Define the data store.