Azure Functions Python HTTP Trigger using Azure Developer CLI

This template repository contains an HTTP trigger reference sample for Azure Functions written in Python and deployed to Azure using the Azure Developer CLI (azd). The sample uses managed identity and a virtual network to make sure deployment is secure by default.

This source code supports the article Quickstart: Create and deploy functions to Azure Functions using the Azure Developer CLI.

Prerequisites

• Python 3.11
• Azure Functions Core Tools
• Azure Developer CLI (AZD)
• To use Visual Studio Code to run and debug locally:
  • Visual Studio Code
  • Azure Functions extension

Initialize the local project

You can initialize a project from this azd template in one of these ways:

• Use this azd init command from an empty local (root) folder:

  azd init --template functions-quickstart-python-http-azd

  Supply an environment name, such as flexquickstart when prompted. In azd, the environment is used to maintain a unique deployment context for your app.

• Clone the GitHub template repository locally using the git clone command:

  git clone https://github.com/Azure-Samples/functions-quickstart-python-azd.git
  cd functions-quickstart-python-azd

  You can also clone the repository from your own fork in GitHub.

Prepare your local environment

Add a file named local.settings.json in the root of your project with the following contents:

{
    "IsEncrypted": false,
    "Values": {
    "AzureWebJobsStorage": "UseDevelopmentStorage=true",
    "FUNCTIONS_WORKER_RUNTIME": "python"
    }
}

Create a virtual environment

The way that you create your virtual environment depends on your operating system. Open the terminal, navigate to the project folder, and run these commands:

Linux/macOS/bash

python -m venv .venv
source .venv/bin/activate

Windows (Cmd)

py -m venv .venv
.venv\scripts\activate

Run your app from the terminal

1. To start the Functions host locally, run these commands in the virtual environment:

   pip3 install -r requirements.txt
   func start

2. From your HTTP test tool in a new terminal (or from your browser), call the HTTP GET endpoint: http://localhost:7071/api/httpget

3. Test the HTTP POST trigger with a payload using your favorite secure HTTP test tool. This example uses the curl tool with payload data from the testdata.json project file:

   curl -i http://localhost:7071/api/httppost -H "Content-Type: text/json" -d @testdata.json

4. When you're done, press Ctrl+C in the terminal window to stop the func.exe host process.

5. Run deactivate to shut down the virtual environment.

Run your app using Visual Studio Code

1. Open the root folder in a new terminal.
2. Run the code . code command to open the project in Visual Studio Code.
3. Press Run/Debug (F5) to run in the debugger. Select Debug anyway if prompted about local emulator not running.
4. Send GET and POST requests to the httpget and httppost endpoints respectively using your HTTP test tool (or browser for httpget). If you have the RestClient extension installed, you can execute requests directly from the test.http project file.

Source Code

The source code for both functions is in the function_app.py code file. Azure Functions requires the use of the @azure/functions library.

This code shows an HTTP GET triggered function:

@app.route(route="httpget", methods=["GET"])
def http_get(req: func.HttpRequest) -> func.HttpResponse:
    name = req.params.get("name", "World")

    logging.info(f"Processing GET request. Name: {name}")

    return func.HttpResponse(f"Hello, {name}!")

This code shows an HTTP POST triggered function:

@app.route(route="httppost", methods=["POST"])
def http_post(req: func.HttpRequest) -> func.HttpResponse:
    try:
        req_body = req.get_json()
        name = req_body.get('name')
        age = req_body.get('age')
        
        logging.info(f"Processing POST request. Name: {name}")

        if name and isinstance(name, str) and age and isinstance(age, int):
            return func.HttpResponse(f"Hello, {name}! You are {age} years old!")
        else:
            return func.HttpResponse(
                "Please provide both 'name' and 'age' in the request body.",
                status_code=400
            )
    except ValueError:
        return func.HttpResponse(
            "Invalid JSON in request body",
            status_code=400
        )

Deploy to Azure

Run this command to provision the function app, with any required Azure resources, and deploy your code:

azd up

Alternatively, you can opt-out of a VNet being used in the sample. To do so, use azd env to configure SKIP_VNET to true before running azd up:

azd env set SKIP_VNET true
azd up

You're prompted to supply these required deployment parameters:

Parameter	Description
Environment name	An environment that's used to maintain a unique deployment context for your app. You aren't prompted when you created the local project using azd init.
Azure subscription	Subscription in which your resources are created.
Azure location	Azure region in which to create the resource group that contains the new Azure resources. Only regions that currently support the Flex Consumption plan are shown.

To learn how to obtain your new function endpoints in Azure along with the required function keys, see Invoke the function on Azure in the companion article Quickstart: Create and deploy functions to Azure Functions using the Azure Developer CLI.

Redeploy your code

You can run the azd up command as many times as you need to both provision your Azure resources and deploy code updates to your function app.

Note

Deployed code files are always overwritten by the latest deployment package.

Clean up resources

When you're done working with your function app and related resources, you can use this command to delete the function app and its related resources from Azure and avoid incurring any further costs:

azd down