Azure Functions
Introduction to Azure Functions
Azure Functions is a serverless compute service that allows you to run small pieces of code, or "functions," in the cloud without explicitly provisioning or managing infrastructure. It's an event-driven, serverless compute platform that can also be described as Function-as-a-Service (FaaS).
Functions are typically triggered by events from Azure services or third-party services. This event-driven model makes Azure Functions ideal for tasks like:
- Processing data changes in Azure Cosmos DB.
- Responding to messages arriving in Azure Service Bus queues.
- Handling HTTP requests for simple APIs.
- Running scheduled tasks.
- Orchestrating workflows with Azure Durable Functions.
Key Concepts
Triggers: An Azure Function is always executed in response to some event. This event is represented by a trigger. A trigger defines how a function is invoked.
Bindings: Bindings allow your function to connect to other Azure services or external services without requiring you to write explicit client-side code. Input bindings pass data into your function, and output bindings send data from your function to another service.
Serverless: You don't need to worry about managing servers, operating systems, or patching. Azure handles all the underlying infrastructure for you.
Scalability: Azure Functions automatically scales your application by adding more instances of the function when demand increases.
Supported Languages
Azure Functions supports a variety of programming languages, including:
- C#
- JavaScript
- TypeScript
- Python
- Java
- PowerShell
- Custom Handlers (for other languages)
Example: HTTP Triggered Function (JavaScript)
Here's a simple JavaScript example of an HTTP-triggered function:
// index.js
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
};
};
This function is triggered by an HTTP request. It checks for a 'name' parameter in the query string or request body and returns a personalized greeting.
For more detailed examples and documentation, visit the official Azure Functions documentation.