Functions with HTTP triggers in Azure - Commands & Configuration

Introduction

Sometimes you want your code to run when someone visits a web address or sends a web request. Azure Functions with HTTP triggers let you do this easily without managing servers.

When you want to run a small piece of code in response to a web request without setting up a full web server

When you need to create a simple API endpoint for your app or website

When you want to process form submissions or webhooks from other services

When you want to quickly test or prototype a web service without complex infrastructure

When you want to run code on demand triggered by HTTP calls from other applications

Config File - function.json

function.json

{
  "bindings": [
    {
      "authLevel": "function",
      "type": "httpTrigger",
      "direction": "in",
      "name": "req",
      "methods": ["get", "post"]
    },
    {
      "type": "http",
      "direction": "out",
      "name": "res"
    }
  ]
}

This file tells Azure that the function should start when it receives an HTTP request.

authLevel: Controls who can call the function. 'function' means a key is needed.

type: 'httpTrigger' means the function starts on HTTP requests.

methods: Lists allowed HTTP methods like GET and POST.

name: Variable names for input request and output response.

Commands

Create a new Azure Functions project using Python runtime to hold your functions.

Terminal

func init MyHttpFunctionProj --worker-runtime python

Expected Output

Creating new project in current directory...

Writing host.json

Writing local.settings.json

Writing requirements.txt

Writing .gitignore

Project created successfully.

→

--worker-runtime - Specifies the language runtime for the function app

Add a new function named HttpExample triggered by HTTP requests with function-level authorization.

Terminal

func new --name HttpExample --template "HTTP trigger" --authlevel function

Expected Output

Function created successfully.

Writing function.json

Writing __init__.py

Writing sample.dat

→

--template - Selects the function template to use

→

--authlevel - Sets the authorization level for the HTTP trigger

Run the function app locally so you can test the HTTP trigger on your machine.

Terminal

func start

Expected Output

Functions:

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

For detailed output, run func with --verbose flag.

Send an HTTP GET request to the function with a query parameter to see the response.

Terminal

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

Expected Output

{"message": "Hello, Azure"}

Key Concept

If you remember nothing else from this pattern, remember: Azure Functions with HTTP triggers let you run code instantly when someone sends a web request, without managing servers.

Common Mistakes

Not setting the correct authorization level in function.json or when creating the function

The function may reject requests or be open to everyone unexpectedly

Set authLevel to 'function' or 'anonymous' explicitly depending on your security needs

Forgetting to run 'func start' before testing the function locally

The function app is not running, so HTTP requests fail

Always start the function app with 'func start' to test locally

Using the wrong HTTP method (e.g., POST instead of GET) when calling the function

The function only listens to specified methods and will ignore others

Check the allowed methods in function.json and use one of them

Summary

Initialize a new Azure Functions project with 'func init' specifying the runtime.

Create a new HTTP-triggered function with 'func new' and set authorization level.

Run the function app locally using 'func start' to test your function.

Send HTTP requests to the function URL to trigger your code and get responses.