Why serverless patterns matter in Azure - Why It Works

Introduction

Serverless patterns help you build apps that automatically handle changes in traffic without you managing servers. They solve the problem of scaling and cost by running code only when needed.

When you want your app to handle sudden spikes in users without crashing.

When you want to pay only for the time your code runs, not for idle servers.

When you want to focus on writing code without worrying about infrastructure.

When you want to build event-driven apps that react to user actions or data changes.

When you want to quickly deploy small pieces of code that work independently.

Commands

This command creates a new Azure Function App using the serverless consumption plan. It sets up the environment where your serverless code will run automatically when triggered.

Terminal

az functionapp create --resource-group example-group --consumption-plan-location eastus --runtime python --functions-version 4 --name example-functionapp --storage-account examplestorageacct

Expected Output

{

  "id": "/subscriptions/00000000-0000-0000-0000-000000000000/resourceGroups/example-group/providers/Microsoft.Web/sites/example-functionapp",

  "location": "eastus",

  "name": "example-functionapp",

  "resourceGroup": "example-group",

  "state": "Running",

  "type": "Microsoft.Web/sites"

}

→

--consumption-plan-location - Specifies the region for the serverless plan where billing is based on usage.

→

--runtime - Sets the programming language runtime for the function app.

→

--functions-version - Specifies the version of Azure Functions runtime to use.

This command deploys your serverless function code packaged in a zip file to the Azure Function App you created.

Terminal

az functionapp deployment source config-zip --resource-group example-group --name example-functionapp --src functionapp.zip

Expected Output

Deployment successful.

→

--src - Specifies the zip file containing your function app code.

This command shows the details of your deployed function app to confirm it is running and ready to handle requests.

Terminal

az functionapp show --resource-group example-group --name example-functionapp

Expected Output

{

  "id": "/subscriptions/00000000-0000-0000-0000-000000000000/resourceGroups/example-group/providers/Microsoft.Web/sites/example-functionapp",

  "state": "Running",

  "defaultHostName": "example-functionapp.azurewebsites.net"

}

Key Concept

If you remember nothing else from this pattern, remember: serverless lets your app automatically scale and only charges you when your code runs.

Common Mistakes

Trying to deploy serverless code without creating a function app first.

The deployment fails because there is no environment to host the code.

Always create the Azure Function App before deploying your code.

Using a fixed server plan instead of the consumption plan for serverless functions.

This causes you to pay for idle server time and loses the benefits of serverless scaling.

Use the consumption plan to pay only for actual function execution time.

Not packaging the function code correctly before deployment.

Deployment fails or the function does not run because the code is incomplete or missing files.

Zip the entire function app folder with all required files before deploying.

Summary

Create an Azure Function App with the consumption plan to enable serverless scaling.

Deploy your function code packaged as a zip file to the function app.

Check the function app status to ensure it is running and ready to handle requests.