Azure Functions

Azure Functions is a serverless compute service that lets you run code on-demand without explicitly provisioning or managing infrastructure. With Functions, you can build applications by connecting readily available services, both Azure and third-party, and third-party services. You pay only for the time your code runs and can scale automatically from zero to hyperscale.

Key Features

Event-driven: Functions are triggered by various events, such as HTTP requests, messages from queues, changes in storage, or timers.
Serverless: No servers to manage. Azure handles all the infrastructure, operating system, and patching.
Scalable: Automatically scales to meet demand, from zero to millions of events.
Cost-effective: Pay only for the compute time your code consumes. A generous free tier is available.
Polyglot: Supports multiple programming languages including C#, F#, Java, JavaScript, PowerShell, Python, and TypeScript.
Integrated: Seamless integration with other Azure services and a wide range of third-party services.

Getting Started

To get started with Azure Functions, you can:

Create a Function App: This is the logical container for your individual functions. You can create it through the Azure portal, Azure CLI, or Visual Studio Code.
Choose a Language and Trigger: Select your preferred programming language and the event that will trigger your function.
Write Your Code: Implement your business logic within the function.
Deploy: Deploy your code to the Azure Functions platform.

Tip: For local development and testing, the Azure Functions Core Tools allow you to run and debug your functions on your local machine before deploying to Azure.

Common Triggers and Bindings

Azure Functions use triggers to initiate execution and bindings to connect to other services:

Triggers

HTTP Trigger: Invokes your function via an HTTP request.
Timer Trigger: Executes your function on a schedule.
Queue Trigger: Fires when a new message is added to an Azure Storage Queue.
Blob Trigger: Executes when a new or updated blob is detected in an Azure Storage container.
Event Hub Trigger: Responds to events published to an Azure Event Hub.
Service Bus Trigger: Activated by messages arriving in an Azure Service Bus queue or topic.

Bindings

Bindings simplify your code by allowing you to declaratively connect to data and services without writing explicit integration code.

Input Bindings: Provide data to your function from a service.
Output Bindings: Send data from your function to a service.

Example: HTTP Trigger

Here's a simple example of an HTTP triggered JavaScript function:

module.exports = async function (context, req) {
    context.log('JavaScript HTTP trigger function processed a request.');

    const name = (req.query.name || (req.body && req.body.name));
    const responseMessage = name
        ? 'Hello, ' + name + '!'
        : "This HTTP triggered function executed successfully. Pass a name in the query string or in the request body for a personalized response.";

    context.res = {
        status: 200,
        body: responseMessage
    };
};

Important: Understanding triggers and bindings is crucial for leveraging the full power of Azure Functions. Explore the official documentation for a comprehensive list and examples.

Learn More

Dive deeper into Azure Functions by exploring these resources: