Functions with queue triggers in Azure - Mini Project: Build & Apply

Functions with queue triggers

📖 Scenario: You are building a simple Azure Function app that processes messages from a storage queue. This is a common pattern to handle tasks asynchronously in cloud applications.

🎯 Goal: Create an Azure Function with a queue trigger that reads messages from a queue named taskqueue. The function should be configured properly to connect to the storage account and trigger on new messages.

📋 What You'll Learn

Create a function.json file with the correct queue trigger binding for queue taskqueue.

Add a configuration setting for the storage account connection string named AzureWebJobsStorage.

Write a simple function in __init__.py that accepts the queue message as a parameter.

Ensure the function.json includes the correct direction, type, and connection properties.

💡 Why This Matters

🌍 Real World

Queue triggered functions are used to process tasks asynchronously, such as image processing, order handling, or background jobs in cloud applications.

💼 Career

Understanding queue triggers is essential for cloud developers and DevOps engineers working with serverless architectures and event-driven systems.

1

Create the initial function.json with queue trigger binding

Create a file named function.json with a binding that triggers on the queue named taskqueue. The binding should have type set to queueTrigger, direction set to in, and name set to msg.

Azure

{
  "bindings": [
    {
      // Your queue trigger binding here
    }
  ]
}

Need a hint?

Remember to specify queueName as taskqueue and set name to msg.

2

Add storage account connection setting in function.json

Add the connection property to the queue trigger binding in function.json and set it to AzureWebJobsStorage to specify the storage account connection string.

Azure

{
  "bindings": [
    {
      "name": "msg",
      "type": "queueTrigger",
      "direction": "in",
      "queueName": "taskqueue",
      // Add connection property here
    }
  ]
}

Need a hint?

The connection property tells the function which app setting holds the storage connection string.

3

Write the Azure Function code to accept the queue message

Create a file named __init__.py and write a function named main that takes a single parameter msg. This function will be triggered when a new message arrives in the queue.

Azure

def main(msg):
    # Your code here

Need a hint?

The function signature must be def main(msg): to match the binding name.

4

Complete the function.json and __init__.py for deployment

Ensure function.json includes all properties: name, type, direction, queueName, and connection. Confirm __init__.py has the main function with parameter msg.

Azure

# Verify the function.json and __init__.py are complete
# Your code here

Need a hint?

Double-check all required properties are present and the function signature matches the binding.