Prerequisites for deploying App Service on Azure Stack Hub

Supported Minimum Azure Stack Hub version	App Service RP version
2301 and newer	2302 Installer (release notes)

Before you deploy Azure App Service on Azure Stack Hub, you must complete the prerequisite steps in this article.

Before you get started

This section lists the prerequisites for both integrated system and Azure Stack Development Kit (ASDK) deployments.

Resource provider prerequisites

If you've already installed a resource provider, you've likely completed the following prerequisites, and can skip this section. Otherwise, complete these steps before continuing:

1. Register your Azure Stack Hub instance with Azure, if you haven't done so. This step is required as you'll be connecting to and downloading items to marketplace from Azure.

2. If you're not familiar with the Marketplace Management feature of the Azure Stack Hub administrator portal, review Download marketplace items from Azure and publish to Azure Stack Hub. The article walks you through the process of downloading items from Azure to the Azure Stack Hub marketplace. It covers both connected and disconnected scenarios. If your Azure Stack Hub instance is disconnected or partially connected, there are additional prerequisites to complete in preparation for installation.

3. Update your Microsoft Entra home directory. Starting with build 1910, a new application must be registered in your home directory tenant. This app will enable Azure Stack Hub to successfully create and register newer resource providers (like Event Hubs and others) with your Microsoft Entra tenant. This is an one-time action that needs to be done after upgrading to build 1910 or newer. If this step isn't completed, marketplace resource provider installations will fail.

   • After you've successfully updated your Azure Stack Hub instance to 1910 or greater, follow the instructions for cloning/downloading the Azure Stack Hub Tools repository.
   • Then, follow the instructions for Updating the Azure Stack Hub Microsoft Entra Home Directory (after installing updates or new Resource Providers).

Installer and helper scripts

1. Download the App Service on Azure Stack Hub deployment helper scripts.

   Note

   The deployment helper scripts require the AzureRM PowerShell module. See Install PowerShell AzureRM module for Azure Stack Hub for installation details.

2. Download the App Service on Azure Stack Hub installer.

3. Extract the files from the helper scripts .zip file. The following files and folders are extracted:

   • Common.ps1
   • Create-AADIdentityApp.ps1
   • Create-ADFSIdentityApp.ps1
   • Create-AppServiceCerts.ps1
   • Get-AzureStackRootCert.ps1
   • BCDR
     • ReACL.cmd
   • Modules folder
     • GraphAPI.psm1

Certificates and server configuration (Integrated Systems)

This section lists the prerequisites for integrated system deployments.

Certificate requirements

To run the resource provider in production, you must provide the following certificates:

• Default domain certificate
• API certificate
• Publishing certificate
• Identity certificate

In addition to specific requirements listed in the following sections, you'll also use a tool later to test for general requirements. See Validate Azure Stack Hub PKI certificates for the complete list of validations, including:

• File format of .PFX
• Key usage set to server and client authentication
• and several others

Default domain certificate

The default domain certificate is placed on the front-end role. User apps for wildcard or default domain request to Azure App Service use this certificate. The certificate is also used for source control operations (Kudu).

The certificate must be in .pfx format and should be a three-subject wildcard certificate. This requirement allows one certificate to cover both the default domain and the SCM endpoint for source control operations.

API certificate

The API certificate is placed on the Management role. The resource provider uses it to help secure API calls. The certificate for publishing must contain a subject that matches the API DNS entry.

Publishing certificate

The certificate for the Publisher role secures the FTPS traffic for app owners when they upload content. The certificate for publishing must contain a subject that matches the FTPS DNS entry.

Identity certificate

The certificate for the identity app enables:

• Integration between the Microsoft Entra ID or Active Directory Federation Services (AD FS) directory, Azure Stack Hub, and App Service to support integration with the compute resource provider.
• Single sign-on scenarios for advanced developer tools within Azure App Service on Azure Stack Hub.

The certificate for identity must contain a subject that matches the following format.

Validate certificates

Before deploying the App Service resource provider, you should validate the certificates to be used by using the Azure Stack Hub Readiness Checker tool available from the PowerShell Gallery. The Azure Stack Hub Readiness Checker Tool validates that the generated PKI certificates are suitable for App Service deployment.

As a best practice, when working with any of the necessary Azure Stack Hub PKI certificates, you should plan enough time to test and reissue certificates if necessary.

Prepare the file server

Azure App Service requires the use of a file server. For production deployments, the file server must be configured to be highly available and capable of handling failures.

Quickstart template for Highly Available file server and SQL Server

A reference architecture quickstart template is now available that will deploy a file server and SQL Server. This template supports Active Directory infrastructure in a virtual network configured to support a highly available deployment of Azure App Service on Azure Stack Hub.

Steps to deploy a custom file server

Provision groups and accounts in Active Directory

1. Create the following Active Directory global security groups:

   • FileShareOwners
   • FileShareUsers

2. Create the following Active Directory accounts as service accounts:

   • FileShareOwner
   • FileShareUser

   As a security best practice, the users for these accounts (and for all web roles) should be unique and have strong usernames and passwords. Set the passwords with the following conditions:

   • Enable Password never expires.
   • Enable User cannot change password.
   • Disable User must change password at next logon.

3. Add the accounts to the group memberships as follows:

   • Add FileShareOwner to the FileShareOwners group.
   • Add FileShareUser to the FileShareUsers group.

Provision groups and accounts in a workgroup

When you use the Azure Resource Manager template, the users are already created.

1. Run the following commands to create the FileShareOwner and FileShareUser accounts. Replace <password> with your own values.

   net user FileShareOwner <password> /add /expires:never /passwordchg:no
   net user FileShareUser <password> /add /expires:never /passwordchg:no
   

2. Set the passwords for the accounts to never expire by running the following WMIC commands:

   WMIC USERACCOUNT WHERE "Name='FileShareOwner'" SET PasswordExpires=FALSE
   WMIC USERACCOUNT WHERE "Name='FileShareUser'" SET PasswordExpires=FALSE
   

3. Create the local groups FileShareUsers and FileShareOwners, and add the accounts in the first step to them:

   net localgroup FileShareUsers /add
   net localgroup FileShareUsers FileShareUser /add
   net localgroup FileShareOwners /add
   net localgroup FileShareOwners FileShareOwner /add
   

Provision the content share

The content share contains tenant website content. The procedure to provision the content share on a single file server is the same for both Active Directory and workgroup environments. But it's different for a failover cluster in Active Directory.

Provision the content share on a single file server (Active Directory or workgroup)

On a single file server, run the following commands at an elevated command prompt. Replace the value for C:\WebSites with the corresponding paths in your environment.

set WEBSITES_SHARE=WebSites
set WEBSITES_FOLDER=C:\WebSites
md %WEBSITES_FOLDER%
net share %WEBSITES_SHARE% /delete
net share %WEBSITES_SHARE%=%WEBSITES_FOLDER% /grant:Everyone,full

Configure access control to the shares

Run the following commands at an elevated command prompt on the file server or on the failover cluster node, which is the current cluster resource owner. Replace values in italics with values that are specific to your environment.

Active Directory

set DOMAIN=<DOMAIN>
set WEBSITES_FOLDER=C:\WebSites
icacls %WEBSITES_FOLDER% /reset
icacls %WEBSITES_FOLDER% /grant Administrators:(OI)(CI)(F)
icacls %WEBSITES_FOLDER% /grant %DOMAIN%\FileShareOwners:(OI)(CI)(M)
icacls %WEBSITES_FOLDER% /inheritance:r
icacls %WEBSITES_FOLDER% /grant %DOMAIN%\FileShareUsers:(CI)(S,X,RA)
icacls %WEBSITES_FOLDER% /grant *S-1-1-0:(OI)(CI)(IO)(RA,REA,RD)

Workgroup

set WEBSITES_FOLDER=C:\WebSites
icacls %WEBSITES_FOLDER% /reset
icacls %WEBSITES_FOLDER% /grant Administrators:(OI)(CI)(F)
icacls %WEBSITES_FOLDER% /grant FileShareOwners:(OI)(CI)(M)
icacls %WEBSITES_FOLDER% /inheritance:r
icacls %WEBSITES_FOLDER% /grant FileShareUsers:(CI)(S,X,RA)
icacls %WEBSITES_FOLDER% /grant *S-1-1-0:(OI)(CI)(IO)(RA,REA,RD)

Prepare the SQL Server instance

For the Azure App Service on Azure Stack Hub hosting and metering databases, you must prepare a SQL Server instance to hold the App Service databases.

For production and high-availability purposes, you should use a full version of SQL Server 2014 SP2 or later, enable mixed-mode authentication, and deploy in a highly available configuration.

The SQL Server instance for Azure App Service on Azure Stack Hub must be accessible from all App Service roles. You can deploy SQL Server within the Default Provider Subscription in Azure Stack Hub. Or you can make use of the existing infrastructure within your organization (as long as there's connectivity to Azure Stack Hub). If you're using an Azure Marketplace image, remember to configure the firewall accordingly.

The App Service installer will check to ensure the SQL Server has database containment enabled. To enable database containment on the SQL Server that will host the App Service databases, run these SQL commands:

sp_configure 'contained database authentication', 1;
GO
RECONFIGURE;
GO

Certificates and server configuration (ASDK)

This section lists the prerequisites for ASDK deployments.

Certificates required for ASDK deployment of Azure App Service

The Create-AppServiceCerts.ps1 script works with the Azure Stack Hub certificate authority to create the four certificates that App Service needs.

To create the certificates, follow these steps:

1. Sign in to the ASDK host using the AzureStack\AzureStackAdmin account.
2. Open an elevated PowerShell session.
3. Run the Create-AppServiceCerts.ps1 script from the folder where you extracted the helper scripts. This script creates four certificates in the same folder as the script that App Service needs for creating certificates.
4. Enter a password to secure the .pfx files, and make a note of it. You must enter it later, in the App Service on Azure Stack Hub installer.

Create-AppServiceCerts.ps1 script parameters

Quickstart template for file server for deployments of Azure App Service on ASDK.

For ASDK deployments only, you can use the example Azure Resource Manager deployment template to deploy a configured single-node file server. The single-node file server will be in a workgroup.

SQL Server instance

For the Azure App Service on Azure Stack Hub hosting and metering databases, you must prepare a SQL Server instance to hold the App Service databases.

For ASDK deployments, you can use SQL Server Express 2014 SP2 or later. SQL Server must be configured to support Mixed Mode authentication because App Service on Azure Stack Hub DOES NOT support Windows Authentication.

The SQL Server instance for Azure App Service on Azure Stack Hub must be accessible from all App Service roles. You can deploy SQL Server within the Default Provider Subscription in Azure Stack Hub. Or you can make use of the existing infrastructure within your organization (as long as there's connectivity to Azure Stack Hub). If you're using an Azure Marketplace image, remember to configure the firewall accordingly.

The App Service installer will check to ensure the SQL Server has database containment enabled. To enable database containment on the SQL Server that will host the App Service databases, run these SQL commands:

sp_configure 'contained database authentication', 1;
GO
RECONFIGURE;
GO

Licensing concerns for required file server and SQL Server

Azure App Service on Azure Stack Hub requires a file server and SQL Server to operate. You're free to use pre-existing resources located outside of your Azure Stack Hub deployment or deploy resources within their Azure Stack Hub Default Provider Subscription.

If you choose to deploy the resources within your Azure Stack Hub Default Provider Subscription, the licenses for those resources (Windows Server Licenses and SQL Server Licenses) are included in the cost of Azure App Service on Azure Stack Hub subject to the following constraints:

• the infrastructure is deployed into the Default Provider Subscription;
• the infrastructure is exclusively used by the Azure App Service on Azure Stack Hub resource provider. No other workloads, administrative (other resource providers, for example: SQL-RP) or tenant (for example: tenant apps, which require a database), are permitted to make use of this infrastructure.

Operational responsibility of file and sql servers

Cloud operators are responsible for the maintenance and operation of the File Server and SQL Server. The resource provider does not manage these resources. The cloud operator is responsible for backing up the App Service databases and tenant content file share.

Retrieve the Azure Resource Manager root certificate for Azure Stack Hub

Open an elevated PowerShell session on a computer that can reach the privileged endpoint on the Azure Stack Hub Integrated System or ASDK Host.

Run the Get-AzureStackRootCert.ps1 script from the folder where you extracted the helper scripts. The script creates a root certificate in the same folder as the script that App Service needs for creating certificates.

When you run the following PowerShell command, you have to provide the privileged endpoint and the credentials for the AzureStack\CloudAdmin.

    Get-AzureStackRootCert.ps1

Get-AzureStackRootCert.ps1 script parameters

Network and identity configuration

Virtual network

Azure App Service on Azure Stack Hub lets you deploy the resource provider to an existing virtual network or lets you create a virtual network as part of the deployment. Using an existing virtual network enables the use of internal IPs to connect to the file server and SQL Server required by Azure App Service on Azure Stack Hub. The virtual network must be configured with the following address range and subnets before installing Azure App Service on Azure Stack Hub:

Virtual network - /16

Subnets

• ControllersSubnet /24
• ManagementServersSubnet /24
• FrontEndsSubnet /24
• PublishersSubnet /24
• WorkersSubnet /21

Create an Identity Application to Enable SSO Scenarios

Azure App Service uses an Identity Application (Service Principal) to support the following operations:

• Virtual machine scale set integration on worker tiers.
• SSO for the Azure Functions portal and advanced developer tools (Kudu).

Depending on which identity provider the Azure Stack Hub is using, Microsoft Entra ID or Active Directory Federation Services (ADFS) you must follow the appropriate steps below to create the service principal for use by the Azure App Service on Azure Stack Hub resource provider.

    Create-AADIdentityApp.ps1

Create an ADFS app

1. Open a PowerShell instance as azurestack\AzureStackAdmin.
2. Go to the location of the scripts that you downloaded and extracted in the prerequisite step.
3. Install PowerShell for Azure Stack Hub.
4. Run the Create-ADFSIdentityApp.ps1 script.
5. In the Credential window, enter your AD FS cloud admin account and password. Select OK.
6. Provide the certificate file path and certificate password for the certificate created earlier. The certificate created for this step by default is sso.appservice.local.azurestack.external.pfx.

    Create-ADFSIdentityApp.ps1

Download items from the Azure Marketplace

Azure App Service on Azure Stack Hub requires items to be downloaded from the Azure Marketplace, making them available in the Azure Stack Hub Marketplace. These items must be downloaded before you start the deployment or upgrade of Azure App Service on Azure Stack Hub:

2. Custom Script Extension v1.9.1 or greater. This item is a VM extension.

Next steps

Install the App Service resource provider