Associate an Azure App Gateway (v2) with a User Assigned Managed Identity and an Azure Key Vault SSL Certificate.

Add-AzAppGatewayUMIandSSLCert.ps1

# Define variables
$ResourceGroupName      = ''
$AppGatewayName         = ''
$ManagedIdentityName    = ''
$KeyVaultName           = ''
$KeyVaultCertficateName = ''

# Get App Gateway and Managed Identity resource objects
$AppGateway = Get-AzApplicationGateway -Name $AppGatewayName -ResourceGroupName $ResourceGroupName
$ManagedIdentity = Get-AzUserAssignedIdentity -Name $ManagedIdentityName -ResourceGroupName $ResourceGroupName

# Associate the Managed Identity with the Application Gateway
Set-AzApplicationGatewayIdentity -ApplicationGateway $AppGateway -UserAssignedIdentityId $ManagedIdentity.Id

# Get the certificate from Key Vault
# Required Azure RBAC Role: Key Vault Secrets User
$Secret = Get-AzKeyVaultSecret -VaultName $KeyVaultName -Name $KeyVaultCertficateName
# Remove the secret version so App Gateway will use the latest version in future syncs
$SecretId = $Secret.Id.Replace($Secret.Version, '')
# Associate the certificate with the Application Gateway
Add-AzApplicationGatewaySslCertificate -KeyVaultSecretId $SecretId -ApplicationGateway $AppGateway -Name $Secret.Name

# Commit the changes to the Application Gateway
Set-AzApplicationGateway -ApplicationGateway $AppGateway