Azure Read Blob Function

function_app.py

# Add the following function to your function_app.py
import azure.functions as func
import logging
import os
from azure.identity import DefaultAzureCredential
from azure.storage.blob import BlobServiceClient

@app.route(route="readblob", auth_level=func.AuthLevel.ANONYMOUS)
def http_read_blob(req: func.HttpRequest) -> func.HttpResponse:
    logging.info('Python HTTP trigger processing a request.')

    # 1. Get the account URL (e.g., https://aaa.blob.core.windows.net)
    # Best practice: Store this in an App Setting
    account_url = os.environ.get("BLOB_STORAGE_ACCOUNT_URL")
    container_name = "mycontainer"
    blob_name = req.params.get('file')

    if not blob_name:
        return func.HttpResponse("Please pass a 'file' name in the query string", status_code=400)

    try:
        # 2. Setup Identity and Client
        # This will use the Managed Identity in Azure
        token_credential = DefaultAzureCredential()
        
        blob_service_client = BlobServiceClient(
            account_url, 
            credential=token_credential
        )

        # 3. Read the blob data
        blob_client = blob_service_client.get_blob_client(container=container_name, blob=blob_name)
        blob_data = blob_client.download_blob().readall()

        return func.HttpResponse(blob_data, mimetype="application/octet-stream")

    except Exception as e:
        logging.error(f"Error reading blob: {e}")
        return func.HttpResponse(f"Failed to read blob: {str(e)}", status_code=500)
        

requirements.txt

azure-storage
azure-identity