Azure Functions is a serverless compute service that lets you run small pieces of code, or "functions," without worrying about infrastructure. It's event-driven, meaning your code runs in response to events that happen in Azure or on your own systems.
What is Serverless Computing?
Serverless computing doesn't mean there are no servers; it means you, as the developer, don't have to manage them. Azure handles the provisioning, scaling, and maintenance of the underlying infrastructure.
- Event-Driven: Functions are triggered by events like HTTP requests, messages from queues, database changes, or scheduled timers.
- Scalability: Azure automatically scales your functions based on demand, ensuring your application remains responsive.
- Pay-per-Execution: You're billed only for the resources your code consumes when it runs, making it cost-effective for many scenarios.
Key Concepts
Functions
A function is the core unit of deployment and execution in Azure Functions. It's a small piece of code that performs a specific task. You can write functions in various programming languages, including:
- C#
- JavaScript
- TypeScript
- Python
- Java
- PowerShell
- and more...
Triggers
A trigger defines how a function is invoked. It's the event that causes your function to execute. Common triggers include:
- HTTP Trigger: Invokes a function when an HTTP request is received.
- Timer Trigger: Invokes a function on a schedule.
- Queue Trigger: Invokes a function when a message is added to an Azure Storage Queue.
- Blob Trigger: Invokes a function when a blob is created or updated in Azure Blob Storage.
Bindings
Bindings connect your function to other Azure services or external data sources. They simplify your code by abstracting the logic for reading from or writing to these services. Bindings can be:
- Input Bindings: Provide data to your function.
- Output Bindings: Allow your function to send data to other services.
For example, a Queue Trigger might be combined with a Table Storage output binding to process messages from a queue and write results to a table.
When to Use Azure Functions
Azure Functions is ideal for a wide range of scenarios, including:
- Real-time data processing: Processing streaming data from IoT devices or logs.
- APIs and microservices: Building lightweight, scalable APIs.
- Scheduled tasks: Running background jobs or cron jobs.
- Event-driven applications: Orchestrating workflows in response to various events.
- Webhooks: Handling incoming webhooks from third-party services.
Getting Started
To get started with Azure Functions, you'll typically need:
- An Azure subscription.
- The Azure Functions Core Tools installed locally for local development and testing.
- Your preferred development environment (e.g., Visual Studio Code with the Azure Functions extension).
Refer to the Getting Started guide for detailed instructions on setting up your development environment and creating your first function.
# Example of creating a new function project
func init MyFunctionProject --worker-runtime node
cd MyFunctionProject
func new --template "HTTP trigger" --name MyHttpTrigger