Azure Functions: Getting Started

Build and deploy serverless applications with Azure Functions.

Welcome to Azure Functions!

Azure Functions is a serverless compute service that enables you to run code on demand without explicitly provisioning or managing infrastructure. It's a great way to build event-driven applications and microservices that are scalable, cost-effective, and easy to develop.

In this tutorial, you'll learn the fundamental steps to create, run, and deploy your first Azure Function.

Prerequisites

Before you begin, ensure you have the following installed:

  • Azure Account: You'll need an active Azure subscription. If you don't have one, you can sign up for a free account.
  • Azure Functions Core Tools: This command-line toolset allows you to develop and test Azure Functions locally. Install Azure Functions Core Tools.
  • Development Environment: Choose your preferred development language and its corresponding tools. Common options include:
    • Visual Studio Code with the Azure Functions extension (recommended for most languages).
    • Visual Studio (for C#).
    • Command Line Interface (CLI) for other languages like Node.js, Python, Java, etc.

Creating Your First Function

Let's create a simple HTTP-triggered function. Open your terminal or command prompt and run the following commands:

Step 1: Create a project folder and navigate into it.

mkdir MyAzureFunctionApp
cd MyAzureFunctionApp

Step 2: Initialize a new Azure Functions project.

The following command will prompt you to choose a language runtime (e.g., C#, Node.js, Python) and create the necessary project files.

func init --worker-runtime

Example for Node.js:

func init --worker-runtime node

Example for Python:

func init --worker-runtime python

Step 3: Create a new HTTP-triggered function.

This command creates a new function within your project. You'll be asked for a function name (e.g., HttpTriggerSample) and an authorization level (e.g., Anonymous for no authentication).

func new --template HttpTrigger --name HttpTriggerSample

After running this, you'll see new files created for your function, typically including an index.js (for Node.js) or __init__.py (for Python), and a function.json file that defines the function's bindings.

Running Your Function Locally

You can test your function locally before deploying it to Azure. Navigate to your project folder in the terminal and start the Functions host:

func start

The output will show the local URL for your HTTP-triggered function. It typically looks like this:

HttpTriggerSample: [GET,POST] http://localhost:7071/api/HttpTriggerSample

Open this URL in your web browser or use a tool like curl or Postman to send a request. You should see a response from your function.

Example using curl:

curl http://localhost:7071/api/HttpTriggerSample?name=Azure

Deploying to Azure

To deploy your function to Azure, you'll need to create an Azure Functions app resource in your Azure subscription. You can do this via the Azure Portal, Azure CLI, or other tools.

Using Azure CLI:

First, log in to your Azure account:

az login

Then, create a resource group and a storage account (required by Functions):

az group create --name MyResourceGroup --location westus2
az storage account create --name mystorageaccount123 --location westus2 --resource-group MyResourceGroup --sku Standard_LRS

Finally, deploy your function app:

func azure functionapp publish  --force

Replace <your_function_app_name> with a globally unique name for your function app. The --force flag can be used to overwrite existing deployments.

After deployment, you'll receive the URL of your function app in Azure. You can access your function via this URL.

Next Steps

Congratulations on creating and deploying your first Azure Function!

Here are some ideas for what to explore next:

  • Different Triggers: Explore other trigger types like Timer, Blob, Queue, and Event Grid triggers.
  • Input/Output Bindings: Learn how to easily connect your functions to other Azure services like Azure Cosmos DB, Azure Storage, and Service Bus using input and output bindings.
  • Advanced Features: Dive into topics like Durable Functions for orchestrating complex workflows, API Management integration, and monitoring your functions.
  • Error Handling and Logging: Implement robust error handling and utilize Application Insights for detailed logging and monitoring.

Continue your learning journey with the comprehensive Azure Functions documentation:

Azure Functions Documentation

Azure Visual Studio Code Node.js Python