How to create a serverless computing function app in Microsoft Azure

Microsoft Azure functions offer access to numerous serverless computing services once you create a function app in which to store them.

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In traditional cloud service situations, businesses create a specific virtual machine (VM), including the allocation of application resources necessary for the task at hand, and then access that VM as needed. The business pays a continuous subscription fee for ready access to the server and its resources.

In a serverless computing situation, businesses only pay for the execution of a specific function on a virtual machine allocated, maintained, and paid for by the cloud service itself. The business does not have to pay for the creation of a VM or for the allocation of its resources, potentially saving a great deal of money. As you can imagine, this holds tremendous appeal for certain businesses operating under specific circumstances.

Microsoft Azure offers numerous serverless computing services under the Functions part of its cloud-based product line. This how-to tutorial explains how to create a simple function application using the Azure Portal.

SEE: Vendor comparison: Microsoft Azure, Amazon AWS, and Google Cloud (Tech Pro Research)

Create a serverless computing function in Microsoft Azure

In Microsoft Azure, a function app serves as the host construct where functions will be executed. A function app lets businesses group functions as a logic unit for easier management, deployment, and sharing of resources.

As always, the first step in the process is to log in to your Microsoft Azure account and navigate to the Portal. From the Portal page, click the "+ Create a resource" button and then select Compute | Function app, as shown in Figure A.

Figure A

There are several boxes to fill in before we can create our function. First, you must give your function app a unique name (such as kaelinfunctions). Next, you must choose an Azure subscription and then what corresponding resource group you would like to use. (Figure B)

Figure B

Next, Azure allows you to choose between the Windows and Linux operating system. Choose the one that best fits your business needs.

The next box allows you to choose between two hosting plans: Consumption and App service, as shown in Figure C. The default Consumption plan adds and scales resources dynamically as required by the functions you use. Under the App service plan, you will need to manage that scaling process yourself. In most circumstances, it is best to leave this setting to the default Consumption plan.

Figure C

The next setting box asks you to specify a region—closer to your primary geographical location is generally better.

The next setting (Figure D) asks you to specify, which programming language you would like to use: Choose .NET for C# and F# functions.

Figure D

The next setting asks you to name either a new storage account for your functions or to specify an existing storage account. The default of creating a new storage account is recommended because you may need to modify an existing account to meet the unique requirements of a function app.

Unless you have a specific business need to do otherwise, it is recommended that you leave the last setting, Application Insights, at its default values.

When you are satisfied with the settings, click the Create button to start the deployment, which could take a few minutes. Once deployed, you should have a function app ready to receive a code or other functions. (Figure E)

Figure E

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By Mark Kaelin

Mark W. Kaelin has been writing and editing stories about the IT industry, gadgets, finance, accounting, and tech-life for more than 25 years. Most recently, he has been a regular contributor to,, and TechRepublic.