Azure Functions: An Introduction to Serverless DevelopmentMSDN Community

What are Azure Functions?

Azure Functions is a serverless compute service that enables you to run small pieces of code, or "functions," in the cloud without having to manage infrastructure. It's event-driven and scales automatically, allowing you to focus on writing code rather than managing servers. This makes it an excellent choice for a wide range of applications, from simple API backends to complex, event-driven workflows.

Key Benefits of Serverless with Azure Functions:

• Event-Driven: Functions can be triggered by a variety of events, such as HTTP requests, timer schedules, messages from queues, or changes in Azure storage.
• Cost-Effective: You only pay for the compute time you consume. When your code isn't running, you're not paying for it.
• Automatic Scaling: Azure Functions automatically scales your application by running code in response to demand.
• Broad Language Support: Write functions in your preferred language, including C#, JavaScript, Python, Java, PowerShell, and more.
• Integration: Easily integrate with other Azure services and popular third-party services.

Getting Started with Azure Functions

Developing Azure Functions typically involves these core components:

1. Function App: A logical container for your functions. It allows you to manage, deploy, and scale your functions together.
2. Triggers: The event that causes a function to execute. Examples include HTTP triggers, Blob triggers, and Queue triggers.
3. Bindings: Declarative connections to other services that allow your function to easily read data from or write data to them.

Example: A Simple HTTP Triggered Function

Let's look at a basic HTTP triggered function written in JavaScript that returns a greeting.

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!"
        : "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
    };
};
            

Common Use Cases

Azure Functions are ideal for:

• Building RESTful APIs and microservices.
• Processing data streams in real-time.
• Automating tasks and workflows.
• Responding to changes in Azure Storage or Databases.
• Orchestrating complex processes with Azure Durable Functions.