What is Azure Functions and How to Use Tutorial

What is Azure Functions and How to Use Tutorial.  Azure Functions is a serverless computing service offered by Microsoft Azure. Comes with a range of features including automatic scaling and integration with other Azure services. Plus, you trigger your functions based on events or schedules. 

Whether you’re building a small app or a large, complex system, Azure Functions helps you to get your code running in the cloud quickly and easily. Sounds like a useful tool to have in your toolkit, right? In this article, you learn about how it works, and how to use it to deploy a web app

Shall we start with article What is Azure Functions and How to Use Tutorial?

What is Azure Functions?

All in all, the service is a cloud based, that enables you to run small pieces of code, known as functions. These functions run in response to specific events. For example, let’s say you want to build an app that sends customers emails on their birthday. Instead of creating a whole app for this feature, you use AF. Hence, Azure Functions (AF) fetches customer data from your data source and sends emails at the designated time. In this case, the birthday is the trigger or event, and the code for sending the email is the function.

Basically, Azure Functions is particularly well suited for small, event driven applications, such as sending emails, automating backups, scheduling tasks, processing orders, working with IoT data, cleaning up databases, and more.

One of the key benefits of it iss that it’s a serverless technology. You don’t have to worry about setting up infrastructure for your applications. Azure allocates resources based on your app’s needs, and you only pay for your code’s run time. In short, you don’t have to write as much code or worry about maintaining infrastructure. As a result, you save time and money. 

Azure Functions Features

Worth noting that AF has gained popularity due to its extensive feature set. Some of them below:

  • Event driven execution – trigger an Azure Function with various events, including HTTP requests, timers, messages added to a queue, or events from other Azure services.
  • Programming Languages – use it with several programming languages, such as C#, F#, JavaScript, TypeScript, Python, and PowerShell. 
  • Scalability – scale compute resources depending on the needs of your function at any one time. As a result, you only pay for your function’s compute time. 
  • Integration – integrate it with various other Azure services such as Azure Storage, Event Hubs, Notification Hubs, Cosmos DB, and Azure Active Directory. It’s also possible to integrate third party services such as Salesforce, Slack, Twilio, and others.   
  • Durable Functions – use it to build long running, stateful functions using the runtime.
  • Security – also offers built in security features like authentication and authorization, as well as integration with Azure  Active Directory.
  • Monitoring and Logging – use it to built in monitoring and logging capabilities. Alternatively, you integrate with Azure Monitor and Log Analytics. As a result, it is easier to evaluate the performance of your functions. 
  • Development and Deployment – there are several options for developing and deploying it. Well, use the AF extension for Visual Studio, the AF Core Tools, or integrate with Azure DevOps.

How Does Azure Functions Work?

When creating a function in AF, you write it in several programming languages, including C#, F#, Python, JavaScript, and PHP. Also, you get to choose between a local development environment or the Azure portal.

After you’ve written and tested your function, you deploy and execute it on Azure without worrying about infrastructure management or capacity planning. Even better, the service comes with a pay-per-execution model, which means you only pay for the number of times your function runs.

Here’s an overview of howit works:

  1. An event or trigger occurs in an event source. This could be a change in data, the arrival of a message, the expiration of a timer, or some other type of event.
  2. Next, the trigger causes an Azure Function to execute. The function runs your code, which is typically defined in a file called run.csx.
  3. Now the function code uses various services or resources, such as a database or a messaging , service to perform its work.
  4. Finally, the function produces output, which could be a message, a file, or some other form of data.

When to Use Azure Functions

  • Run periodic or on demand jobs like clean up tasks and data processing
  • Process data from external sources such as social media feeds and IoT devices. 
  • Build serverless APIs or microservices
  • Integrate with other Azure services and other external services. 

When Not to Use Azure Functions

  • When you have long running processes. Remember, Azure Functions works best for short lived stateless functions
  • If you strictly need low latency response times.
  • When your application has a lot of complex dependencies. 
  • If your application has strict compliance requirements. For example, there are situations where it’s necessary to run your application in a more controlled environment

Azure Functions Pros

  • Azure is more geared towards enterprise needs compared to the Functions as a Service (FaaS) offerings from Google Cloud (Google Cloud  Functions) and AWS (AWS Lambda). The thing is, it provides support for stateful applications through the Durable Functions extension. Great for serverless and deploying stateful applications. 
  • Authentication comes pre configured, so you don’t have to fiddle with configurations when working with AF. 
  • Supports .NET languages and provides deeper integration with the tool kits .NET developers use. 

Azure Functions Cons

  • Pricing is confusing and not always be cost effective, especially for enterprise customers.  Premium and dedicated plans tend to be more expensive. In addition, enabling the “always on” instance setting is cost negate as a Service model.
  • The low tier plans come with limited features, and the pricing for storage is not always transparent, which could result in unexpected costs. Also, be aware of potential hidden costs, such as adding a storage account to the function’s compute.

How to Use Azure Functions

In order to use Azure Functions, you need to create a function app in the Azure portal and then create one or more functions within the app. You write the code for your functions using a variety of languages, such as C#, F#, and JavaScript. Also, you use a variety of triggers and bindings to connect your functions to other Azure services and external APIs.

Here are a few ways you use Azure Functions:

  • Web service: thanks to AF you build and deploy HTTP triggered functions that you use via a URL. Use these functions to create a REST API or to build webhooks and integrations with other services.
  • Background task: here  you run tasks on a schedule or in response to specific events. For example, you apply timer trigger to run a function every hour, or use an event trigger to run a function when a new message is added to a queue.
  • Data processing service: process and analyse data from a variety of sources, such as IoT devices, social media feeds, and log files. In this instance Azure Functions performs data transformations, runs machine learning models, and generate reports.
  • Microservices platform: moreover you build and deploy modular, scalable, and independent microservices that are composed into larger applications.

How to Create an Azure Function

Now that you have a basic understanding of AF, it’s time to try it out for yourself. Let’s get started with a tutorial. Further, to create an Azure Function, you use the Azure portal, AF extension for Visual Studio, or AF Core Tools. For this tutorial, you’ll need an Azure account. Here is a general outline of the steps involved:

  1. Go to the Azure portal (https://portal.azure.com) and click on the “Create a resource” button. You’ll find the button on the top left corner of your screen.  
  2. Navigate to the search box and type “Function App”. Press Enter. 
  3. Next, click on “Function App” in the search results. 
  4. Navigate to the “Create Function App” blade and enter a name for your function app in the “Name” field. Pick a name that is unique across Azure, so you may need to try a few different names, if your first choice is already taken.
  5. Now it’s time to set up your account by entering the following information:
  • Subscription
  • Resource Group
  • Function App name
  • Runtime stack 
  • Region

Leave the default values if you’re not sure what these are. 

Next Steps

6. Next, select a hosting location for your function app. 

7. Click “Create” to create your function app. This may take a few minutes.

8. Once you’ve created the function app, click the “Go to resource” button to view the details of your function app.

9. Click on the “Add” button to add a new function to your function app. 

10. In the “Create function” blade, select a trigger for your function. A trigger is an event that causes your function to run. For example, you could select an HTTP trigger to create an HTTP endpoint that you can call to run your function, or you could select a timer trigger to have your function run on a schedule.

11. Enter a name for your function, and then click the “Create” button.

12. In the code editor, write the code for your function.

13. Save your changes and test your function by clicking the “Run” button or by calling the function using the HTTP trigger URL.

Azure Function Example: Creating a Birthday Reminder

Below is an example of an Azure Function that sends a birthday message to a customer using the SendGrid email service.

Firstly, set up a SendGrid account and obtain an API key. Then, in the Azure portal, create a new Azure Function and select the “SendGrid” trigger. Once the function is created, paste in the following C# code:

					#r "SendGrid"

using System;
using System.Threading.Tasks;
using Microsoft.AspNetCore.Mvc;
using Microsoft.Azure.WebJobs;
using Microsoft.Azure.WebJobs.Extensions.Http;
using Microsoft.AspNetCore.Http;
using Microsoft.Extensions.Logging;
using SendGrid.Helpers.Mail;

namespace BirthdayFunction
    public static class SendBirthdayMessage
        public static async Task Run(
            [HttpTrigger(AuthorizationLevel.Function, "post", Route = null)] HttpRequest req,
            ILogger log)
            log.LogInformation("Sending birthday message.");

            // Retrieve the email address and name of the customer from the request body
            string email = req.Form["email"];
            string name = req.Form["name"];

            // Set the SendGrid API key
            string apiKey = Environment.GetEnvironmentVariable("SENDGRID_API_KEY");
            var client = new SendGridClient(apiKey);

            // Construct the email message
            var from = new EmailAddress("hello@example.com", "Birthday Bot");
            var subject = "Happy Birthday!";
            var to = new EmailAddress(email, name);
            var htmlContent = $"<p>Happy birthday, {name}!</p>";
            var msg = MailHelper.CreateSingleEmail(from, to, subject, "", htmlContent);

            // Send the email
            await client.SendEmailAsync(msg);

            return new OkObjectResult("Birthday message sent.");


This function expects the “email" and “name" of the customer to be passed in the request body as form data.

Thank you for reading What is Azure Functions and How to Use Tutorial. We shall conclude this article blog.

What is Azure Functions and How to Use Tutorial Conclusion

In conclusion, Azure Functions is a powerful and flexible cloud based platform that allows developers to create and deploy serverless functions in several languages and on a pay per execution basis. Lastly, it offers a range of features and benefits, including the ability to scale automatically, integrate with other Azure services, and trigger functions based on events or schedules.

By following the steps outlined in this article, you easily get started with Azure Functions and begin building and deploying your functions in the cloud. Whether you are a beginner or an experienced developer, Azure Functions provides a convenient and cost effective way to build and deploy your applications in the cloud.

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Avatar for Richard Kanyoro
Richard Kanyoro

The world’s biggest problems can be solved by progressively solving the little ones. I write to help people solve the “little” tech problems they face.

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