Lab 09a - Implement Web Apps

Student lab manual

Lab scenario

You need to evaluate the use of Azure Web apps for hosting Contoso’s web sites, hosted currently in the company’s on-premises data centers. The web sites are running on Windows servers using PHP runtime stack. You also need to determine how you can implement DevOps practices by leveraging Azure web apps deployment slots.

Note: An interactive lab simulation is available that allows you to click through this lab at your own pace. You may find slight differences between the interactive simulation and the hosted lab, but the core concepts and ideas being demonstrated are the same.

Objectives

In this lab, you will:

Task 1: Create an Azure web app
Task 2: Create a staging deployment slot
Task 3: Configure web app deployment settings
Task 4: Deploy code to the staging deployment slot
Task 5: Swap the staging slots
Task 6: Configure and test autoscaling of the Azure web app

Estimated timing: 30 minutes

Architecture diagram

Instructions

Exercise 1

Task 1: Create an Azure web app

In this task, you will create an Azure web app.

Sign in to the Azure portal.
In the Azure portal, search for and select App services, and, on the App Services blade, click + Create.

On the Basics tab of the Create Web App blade, specify the following settings (leave others with their default values):

Setting	Value
Subscription	the name of the Azure subscription you are using in this lab
Resource group	the name of a new resource group az104-09a-rg1
Web app name	any globally unique name
Publish	Code
Runtime stack	PHP 8.2
Operating system	Linux
Region	the name of an Azure region where you can provision Azure web apps
Pricing plans	accept the default configuration

Click Review + create. On the Review + create tab of the Create Web App blade, ensure that the validation passed and click Create.

Note: Wait until the web app is created before you proceed to the next task. This should take about a minute.
On the deployment blade, click Go to resource.

Task 2: Create a staging deployment slot

In this task, you will create a staging deployment slot.

On the blade of the newly deployed web app, click the Default domain link to display the default web page in a new browser tab.
Close the new browser tab and, back in the Azure portal, in the Deployment section of the web app blade, click Deployment slots.

Note: The web app, at this point, has a single deployment slot labeled PRODUCTION.

Click + Add slot, and add a new slot with the following settings:

Setting	Value
Name	staging
Clone settings from	Do not clone settings

Back on the Deployment slots blade of the web app, click the entry representing the newly created staging slot.

Note: This will open the blade displaying the properties of the staging slot.
Review the staging slot blade and note that its URL differs from the one assigned to the production slot.

Task 3: Configure web app deployment settings

In this task, you will configure web app deployment settings.

On the staging deployment slot blade, in the Deployment section, click Deployment Center and then select the Settings tab.

Note: Make sure you are on the staging slot blade (rather than the production slot).
On the Settings tab, in the Source drop-down list, select Local Git and click the Save button
On the Deployment Center blade, copy the Git Clone Uri entry to Notepad.

Note: You will need the Git Clone Uri value in the next task of this lab.

On the Deployment Center blade, select the Local Git/FTPS credentials tab, in the User Scope section, specify the following settings, and click Save.

Setting	Value
User name	any globally unique name (see note)
Password	any password that satisfies complexity requirements (see note)

Note: Copy these credentials to Notepad. You will need them later.

Note: These credentials will be passed through the URI. Do not include any special characters that affect the interpretation of the URI. For example, @, $, or #. An asterick or plus sign (in the middle of the string) would work.

Task 4: Deploy code to the staging deployment slot

In this task, you will deploy code to the staging deployment slot.

In the Azure portal, open the Azure Cloud Shell by clicking on the icon in the top right of the Azure Portal.
If prompted to select either Bash or PowerShell, select PowerShell.

Note: If this is the first time you are starting Cloud Shell and you are presented with the You have no storage mounted message, select the subscription you are using in this lab, and click Create storage.
From the Cloud Shell pane, run the following to clone the remote repository containing the code for the web app.
```
git clone https://github.com/Azure-Samples/php-docs-hello-world
```
From the Cloud Shell pane, run the following to set the current location to the newly created clone of the local repository containing the sample web app code.
```
Set-Location -Path $HOME/php-docs-hello-world/
```
From the Cloud Shell pane, run the following to add the remote git (make sure to replace the [deployment_user_name] and [git_clone_uri] placeholders with the value of the Deployment Credentials user name and Git Clone Uri, respectively, which you identified in previous task):
```
git remote add [deployment_user_name] [git_clone_uri]
```
Note: The value following git remote add does not have to match the Deployment Credentials user name, but has to be unique
From the Cloud Shell pane, run the following to push the sample web app code from the local repository to the Azure web app staging deployment slot (make sure to replace the placeholder values with the value of the Deployment Credentials user name and password and the app name, which you identified in previous task):
```
 git push https://<deployment-username>:<deployment-password>@<app-name>-staging.scm.azurewebsites.net/<app-name>.git master
```
Close the Cloud Shell pane.
On the staging slot blade, click Overview and then click the Default domain link to display the default web page in a new browser tab.
Verify that the browser page displays the Hello World! message and close the new tab.

Task 5: Swap the staging slots

In this task, you will swap the staging slot with the production slot

Navigate back to the blade displaying the production slot of the web app.
In the Deployment section, click Deployment slots and then, click Swap toolbar icon.
On the Swap blade, review the default settings and click Swap.
Click Overview on the production slot blade of the web app and then click the Default domain link to display the web site home page in a new browser tab.
Verify the default web page has been replaced with the Hello World! page.

Task 6: Configure and test autoscaling of the Azure web app

In this task, you will configure and test autoscaling of Azure web app.

On the blade displaying the production slot of the web app, in the Settings section, click Scale out (App Service plan).
From the Scaling section select the Rules Based option, then click on the Manage rules based scaling link.
Click Custom autoscale.

Note: You also have the option of scaling the web app manually.
Select Scale based on a metric and click + Add a rule

On the Scale rule blade, specify the following settings (leave others with their default values):

Setting	Value
Metric source	Current resource
Metric namespace	standard metrics
Metric name	CPU Percentage
Operator	Greater than
Metric threshold to trigger scale action	10
Duration (in minutes)	1
Time grain statistic	Maximum
Time aggregation	Maximum
Operation	Increase count by
Instance count	1
Cool down (minutes)	5

Note: These values do not represent a realistic configuration, since their purpose is to trigger autoscaling as soon as possible, without extended wait period.

Click Add and, back on the App Service plan scaling blade, specify the following settings (leave others with their default values):

Setting	Value
Instance limits Minimum	1
Instance limits Maximum	2
Instance limits Default	1

Click Save.

Note: If you got an error complaining about ‘microsoft.insights’ resource provider not being registered, run az provider register --namespace 'Microsoft.Insights' in your cloudshell and retry saving your auto scale rules.
In the Azure portal, open the Azure Cloud Shell by clicking on the icon in the top right of the Azure Portal.
If prompted to select either Bash or PowerShell, select PowerShell.
From the Cloud Shell pane, run the following to identify the URL of the Azure web app.
```
$rgName = 'az104-09a-rg1'

$webapp = Get-AzWebApp -ResourceGroupName $rgName
```
From the Cloud Shell pane, run the following to start and infinite loop that sends the HTTP requests to the web app:
```
while ($true) { Invoke-WebRequest -Uri $webapp.DefaultHostName }
```
Minimize the Cloud Shell pane (but do not close it) and, on the web app blade, in the Settings section, click Scale out (App Service plan).
Monitor the utilization and the number of instances for a few minutes.

Note: You may need to Refresh the page.
Once you notice that the number of instances has increased to 2, reopen the Cloud Shell pane and terminate the script by pressing Ctrl+C.
Close the Cloud Shell pane.

Clean up resources

Note: Remember to remove any newly created Azure resources that you no longer use. Removing unused resources ensures you will not see unexpected charges.

Note: Don’t worry if the lab resources cannot be immediately removed. Sometimes resources have dependencies and take a long time to delete. It is a common Administrator task to monitor resource usage, so just periodically review your resources in the Portal to see how the cleanup is going.

In the Azure portal, open the PowerShell session within the Cloud Shell pane.
List all resource groups created throughout the labs of this module by running the following command:
```
Get-AzResourceGroup -Name 'az104-09a*'
```
Delete all resource groups you created throughout the labs of this module by running the following command:
```
Get-AzResourceGroup -Name 'az104-09a*' | Remove-AzResourceGroup -Force -AsJob
```
Note: The command executes asynchronously (as determined by the -AsJob parameter), so while you will be able to run another PowerShell command immediately afterwards within the same PowerShell session, it will take a few minutes before the resource groups are actually removed.

Review

In this lab, you have:

Created an Azure web app
Created a staging deployment slot
Configured web app deployment settings
Deployed code to the staging deployment slot
Swapped the staging slots
Configured and test autoscaling of the Azure web app