# Lab 09: Implement Web Apps

**Objective:** This lab introduces Azure Web Apps. You'll create a web app, deploy a simple "Hello World" application from GitHub, configure a staging slot, swap slots, and configure autoscaling.

**Scenario:** Your organization is migrating on-premises websites to Azure. You'll explore using Azure Web Apps (part of Azure App Service) to host a PHP-based website, replacing aging on-premises hardware.

**Key Concepts:**

* **Azure Web Apps:** A fully managed platform-as-a-service (PaaS) for hosting web applications. Supports various languages and frameworks (e.g., .NET, PHP, Node.js, Java, Python).
    
* **App Service Plan:** Defines the compute resources (VM size, number of instances) allocated to your web app. Determines pricing and scaling capabilities.
    
* **Deployment Slots:** Separate environments (e.g., staging, production) within a single web app. Allow you to test changes before deploying them to production.
    
* **Deployment Center:** Manages deployments to your web app, supporting various sources like GitHub, Azure Repos, and local Git.
    
* **Autoscaling:** Automatically adjusts the number of instances in your App Service plan based on demand (e.g., CPU usage).
    
* **Swapping Slots:** A zero-downtime deployment technique. Traffic is redirected from one slot (e.g., staging) to another (e.g., production) with minimal interruption.
    

**Lab Tasks**

## **Task 1: Create and Configure an Azure Web App (5 minutes)**

1. **Sign In:** Log in to the Azure portal ([https://portal.azure.com](https://portal.azure.com/)).
    
2. **Create Web App:** Search for and select "App Services" and click "+ Create" -> "Web App."
    
    * **Basics:**
        
        * Name: `WebApp48965394` (or a *unique* name) - *This will be part of your web app's URL.*
            
        * Publish: `Code`
            
        * Runtime stack: `PHP 8.2`
            
        * Operating System: `Linux`
            
        * Pricing plan:  `Premium V3 P1v3` (This is important for autoscaling later)
            
        * Zone Redundancy: accept the defaults.
            
    * Click "Review + create," then "Create."
        

![](https://cdn.hashnode.com/res/hashnode/image/upload/v1741034115808/13151fdf-ace5-40db-a249-618a59ec2682.png align="center")

3. **Go to Resource:** Once deployed, click "Go to resource."
    

* If the deployment failed, use another region. (e.g. Canada Central!)
    

4. **Test Default Page:** On the web app's "Overview" blade, click the "Default domain" link. You should see the default Azure App Service welcome page. Close the new browser tab.
    

## **Task 2: Create a Deployment Slot**

1. **Add Staging Slot:**
    
    * In your web app's resource, under "Deployment," select "Deployment slots."
        
    * Click "Add slot."
        
        * Name: `staging`
            
        * Clone settings from: `Do not clone settings`
            
    * Click "Add."
        
2. **Verify Staging Slot URL:** Click on the newly created `staging` slot. Note that it has a different URL than the production slot (it will include `-staging` in the name).
    

![](https://cdn.hashnode.com/res/hashnode/image/upload/v1741035788515/956e3b3e-d196-45cc-8b29-464df07d3157.png align="center")

## **Task 3: Configure Web App Deployment Settings (5 minutes)**

1. **Deployment Center (Staging Slot):**
    
    * **Important:** Make sure you are on the `staging` slot's blade (not the production slot). You can verify by checking the URL or the name at the top of the blade.
        
    * Under "Deployment," select "Deployment Center."
        
    * **Settings:**
        
        * Source: `External Git`
            
        * Repository: `https://github.com/Azure-Samples/php-docs-hello-world`
            
        * Branch: `master`
            
    * Click "Save."
        

![](https://cdn.hashnode.com/res/hashnode/image/upload/v1741036070762/e412efda-2161-4fe0-9d26-980db099f762.png align="center")

2. **Test Staging Slot:**
    
    * Go to the "Overview" blade of the `staging` slot.
        
    * Click the "Default domain" link. You should see the "Hello World" application. This may take a minute or two to deploy; refresh the page if needed.
        

## **Task 4: Swap Deployment Slots**

1. **Swap Slots:**
    
    * Navigate back to the *main* web app's resource (not the staging slot). The easiest way is to use the breadcrumbs at the top of the portal.
        
    * Under "Deployment," select "Deployment slots."
        
    * Click "Swap."
        
    * Verify that the Source is `staging` and the Target is `production`.
        
    * Click "Start Swap."
        

![](https://cdn.hashnode.com/res/hashnode/image/upload/v1741036227541/a469d8c4-6d58-459d-9175-92aec54ad4a1.png align="center")

2. **Test Production Slot:**
    
    * Go to the "Overview" blade of the *main* web app (not the staging slot).
        
    * Click the "Default domain" link. You should now see the "Hello World" application on the *production*URL. The swap is complete.
        
    * **Copy the default domain URL** - you will need it for load testing.
        

## **Task 5: Configure and Test Autoscaling**

1. **Configure Autoscaling:**
    
    * Go to the *main* web app's resource (not the staging slot).
        
    * Under "Settings," select "Scale out (App Service plan)."
        
    * Choose `Automatic`. Note the Rules Based option.
        
    * Set the **maximum burst** field to `2` and cliock on save. ("maximum burst" refers to the maximum number of instances that an App Service Plan can scale out to during periods of high demand.)
        

![](https://cdn.hashnode.com/res/hashnode/image/upload/v1741036758048/f59c677e-e206-47f0-a16f-d76fbfdd9bf5.png align="center")

![](https://cdn.hashnode.com/res/hashnode/image/upload/v1741037158878/3e245cc9-8556-4895-bbff-1e0b2381100c.png align="center")

2. **Create a Load Test:**
    
    * In the left pane, select `Diagnose and solve problems`.
        
    * In the "Load Test your App" box, select "Create Load Test."
        
    * Click "+ Create" and give your load test a *unique* name.
        
    * Select Review + create and then Create.
        
    * Wait for the test to be created, select Go to resource.
        

![](https://cdn.hashnode.com/res/hashnode/image/upload/v1741037425863/959ad89e-804f-4f9b-a440-9bf23ca9e40a.png align="center")

3. **Add HTTP Request to Load Test**
    
    * From the Overview | Add HTTP requests, select Create.
        
    * On the "Test plan" tab, click "Add request."
        
    * In the "URL" field, paste your "Default domain" URL (from Task 4, Step 2). Ensure it begins with `https://`.
        
    * Click "Review + create," then "Create." (This may take a couple of minutes.)
        

![](https://cdn.hashnode.com/res/hashnode/image/upload/v1741037508601/5ddcc9f8-d364-4926-b7e0-dd6115e57844.png align="center")

4. **Observe Test Results (Briefly):**
    
    * Review the test results, looking at "Virtual users," "Response time," and "Requests/sec."
        
    * Click "Stop" to end the test. You *don't* need to wait for the full test to complete for the purposes of this lab. The goal is to *initiate* a load test, not to fully analyze its results.
        

![](https://cdn.hashnode.com/res/hashnode/image/upload/v1741037897465/43ac724e-b8ac-4359-b165-3ca39573e3c7.png align="center")