README.md

Use Azure Functions to build a RESTful API

Create an Azure Functions serverless API that returns a list of pets to be adopted. In this lab, you will learn how to create a basic REST API using Node.js Azure Functions and add dependencies from npm.

Prerequisites

If you are not at an event, please see REQUIREMENTS to install the prerequisites for this lab.

Create a Function App

Use the Azure Functions extension to create a new function app.

• Open Visual Studio Code Insiders
• In the Activity bar (on left side), select the Azure icon
• Click the Create New Project button (the in the explorer)

• Select projects/pets folder from the

Now the Create new project wizard appears, enter the following

• Select JavaScript for the language of the Function App

• Select HTTP trigger for the template

• Replace the default function name HttpTrigger with pets

• Select Anonymous for the Authorization level

• Select Open in current window

The HTTP Trigger function just created is opened in the editor window.

Run the Function locally

Using a template to create the function, creates a working Http Trigger function we can test locally.
Let's try it now:

• In the Menu bar, select Start Debugging from the Debug menu or press Fn+F5

A Terminal opens with the debug output.

Debug automatically excutes run npm install, to install any depencies, and starts the Azure Functions host.

Once the host is started, the URL appears.

Hold Crtl while click the URL or type http://localhost:7071/api/pets in a browser.

You'll see a message that says "Please pass a name on the query string or in the request body"

• Add a query parameter, name, to the URL, ?name=OSCON, press Enter and now the page shows: "Hello OSCON"

  http://localhost:7071/api/pets?name=OSCON

In the Menu bar, select Stop Debugging from the Debug menu or press Shift+Fn+F5

Finding pets for adoption

Now we'll update the function to pull a list of pets that are available for adoption using a module from npm that uses a Pet Finder API with a specific configuration.

• Open a Terminal Window from the Terminal menu or Ctrl+Shift+`

• In the Terminal, install the pet module from npm by running npm install @frontendmasters/pet --save.

• Replace the default code in the index.js with:

const pet = require("@frontendmasters/pet");

module.exports = async function(context, req) {
  const response = await pet.animals();

  if (!response.animals)
    return (context.res = {
      status: 500,
      body: response.message
    });

  context.res = {
    body: response.animals
  };
};

Now test your new code:

• In the Menu bar, select Start Debugging from the Debug menu or press Fn+F5
• Start Debug again and load the URL http://localhost:7071/api/pets

  This time, you'll see a JSON array of pets along with links to photos and more information for each

At this point, you can hook a front-end up to you API and start helping lovely animals find happy homes!

In the Menu bar, select Stop Debugging from the Debug menu or press Shift+Fn+F5

Next steps

• Sample app with an Angular front end connected to Azure Functions