Create and configure an Azure Function App

Azure Functions is a serverless computing service provided by Microsoft Azure that allows you to run event-driven code without the need to manage infrastructure. In this article, we will explore how to create and configure an Azure Function App.

Prerequisites

Before we proceed, ensure that you have an active Azure subscription and are familiar with basic concepts such as resource groups and Azure App Service plans.

Create an Azure Function App

To create an Azure Function App, follow these steps:

1. Sign in to the Azure Portal (portal.azure.com).
2. Click on the “Create a resource” button (+) in the upper left-hand corner of the portal.
3. Search for “Function App” and select the Function App option from the available services.
4. Click the “Create” button to start the creation process.
5. Fill in the required information for the new Function App:
   • App name: Enter a globally unique name for your Function App. This name will be used as part of the URL for your function endpoints.
   • Subscription: Select the appropriate Azure subscription.
   • Resource Group: Choose an existing resource group or create a new one to logically group your resources.
   • OS: Choose either Windows or Linux as per your preference.
   • Hosting Plan: Select an appropriate hosting plan. Consumption plan is recommended for most scenarios as it automatically scales to support incoming requests.
   • Location: Choose the region where your Function App will be hosted. Select a location close to your target audience for better performance.
   • Runtime Stack: Select either .NET or Node.js as per your preferred programming language.
6. Click “Next: Monitoring” to configure monitoring settings as per your requirements. You can optionally enable Application Insights for detailed monitoring and diagnostics.
7. Click “Review + Create” to review the settings and then click “Create” to create the Function App.

Once the Function App is created, you can proceed with configuring additional settings and creating your functions.

Configure the Azure Function App

To configure the settings of your Azure Function App, follow these steps:

1. Navigate to your Function App in the Azure Portal.
2. Select “Functions” from the left-hand navigation menu.
3. Click on the “+ Add” button to create a new function.
4. Choose a development environment (Azure Portal, Visual Studio, or Visual Studio Code) and select the preferred programming language.
5. Select a trigger for the function. Triggers can include HTTP requests, scheduled timers, queues, and many more. Choose the appropriate trigger for your scenario.
6. Configure the trigger settings based on your requirements. For example, if you select an HTTP trigger, you can specify the HTTP method, authentication, and route.
7. Write the code for your function. You can use the online code editor provided in the Azure Portal or develop the function locally and publish it to the Function App.

Here’s an example of an HTTP-triggered function written in C#:

using System;
using Microsoft.AspNetCore.Http;
using Microsoft.Azure.WebJobs;
using Microsoft.Azure.WebJobs.Extensions.Http;
using Microsoft.Extensions.Logging;

public static class MyFunction
{
[FunctionName(“MyFunction”)]
public static async Task Run(
[HttpTrigger(AuthorizationLevel.Function, “get”, “post”, Route = null)] HttpRequest req,
ILogger log)
{
log.LogInformation(“C# HTTP trigger function processed a request.”);

string name = req.Query[“name”];

string requestBody = await new StreamReader(req.Body).ReadToEndAsync();
dynamic data = JsonConvert.DeserializeObject(requestBody);
name = name ?? data?.name;

return name != null
? (ActionResult)new OkObjectResult($”Hello, {name}”)
: new BadRequestObjectResult(“Please pass a name on the query string or in the request body”);
}
}

Once you have configured the trigger and implemented the function code, click the “Save” button to save your function.

Congratulations! You have successfully created and configured an Azure Function App. Now, you can add more functions as needed and take advantage of the scalability and flexibility provided by Azure Functions to build event-driven applications in the cloud.