Creating Azure Functions

This guide walks you through the essential steps to create your first Azure Functions, covering local development and deployment.

Prerequisites

Steps to Create a Function

  1. Initialize a Local Project

    Open your terminal or command prompt and navigate to the directory where you want to create your project. Run the following command:

    func init MyFunctionApp --

    Replace <language> with your preferred runtime, e.g., dotnet, node, python, powershell, or custom.

    Note: This command creates a new folder named MyFunctionApp with the necessary project files for a Functions app.

  2. Create a New Function

    Navigate into your project directory and create a new function:

    cd MyFunctionApp
    func new --name HttpTrigger --template "HTTP trigger" --authlevel "anonymous"

    This command creates a new function named HttpTrigger using the "HTTP trigger" template. You can choose other templates like Queue trigger, Blob trigger, etc. The --authlevel parameter controls access authorization.

    Tip: The Azure Functions extension for VS Code provides a graphical interface to create new functions, making this process even simpler.

  3. Develop Your Function Logic

    Open the newly created function's folder (e.g., HttpTrigger) in your code editor. You'll find files like index.js (for Node.js), __init__.py (for Python), or HttpTrigger.cs (for .NET).

    Edit the function code to implement your desired logic. For an HTTP trigger, you'll typically process the incoming request and return a response.

    Example (Node.js):

    // HttpTrigger/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, /* Defaults to 200 */
    body: responseMessage
    };
    };

  4. Run Your Function Locally

    From the root of your project directory, run the Azure Functions host:

    func start

    This command builds and starts your Functions app locally. It will output the local URLs for your HTTP-triggered functions. You can then test your function using a browser or tools like cURL or Postman.

  5. Deploy to Azure

    Once you're satisfied with your function's local behavior, you can deploy it to Azure. The most common methods include:

    • Using the Azure Functions Core Tools CLI: func azure functionapp publish <FunctionName>
    • Using Visual Studio Code's Azure Functions extension.
    • Using CI/CD pipelines (e.g., Azure DevOps, GitHub Actions).
    Important: Ensure you have logged into Azure CLI (az login) or VS Code's Azure extension before deploying.

Next Steps

Now that you've created your first Azure Function, explore other aspects: