Category Archives: Azure

ARM, Automation, Azure, Azure Virtual Desktop, Powershell

Publishing an MSIX as CIM to AVD in a Pipeline

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I wanted to put this out there as it felt like a nifty way to pipeline AVD MSIX files into AVD without any user interaction (other than a pipeline kicking off the script).

https://github.com/jflieben/assortedFunctionsV2/blob/main/publish-MSIXPackageToHostpool.ps1

Basically, above will grab the MSIX file from a known Azure Fileshare (after mounting). It’ll read the MSIX’s primary CIM file for meta data, use the Azure Rest API to add it to the hostpool and then updates a param file of an ARM template which can be used to e.g. update the appgroup in Azure.

You’ll need some background knowledge to re-use above in your specific situation 🙂

Code example:

#create the MSIX package object in the hostpool. Ensure the lastUpdated value is always unique otherwise it will fail to overwrite an existing package with the same value
$apiPostData = @{
    "properties" = @{
        "displayName" = if($packageMeta -match "(?<=<DisplayName>)(.*?)(?=<\/DisplayName>)"){$matches[1]}else{Throw "No display name found in AppManifest"}
        "imagePath" = $imagePath
        "isActive" = $True
        "isRegularRegistration" = $False
        "lastUpdated" = (get-itemproperty $packageFolder.FullName).LastWriteTimeUtc.AddSeconds((Get-Random -Minimum "-150" -Maximum 150)).ToString("yyyy-MM-ddThh:mm:ss")
        "packageApplications" = $packageApplications
        "packageDependencies" = @()
        "packageFamilyName" = "$($packageShortName)_$($packageFamily)"
        "packageName" = $packageShortName
        "packageRelativePath" = "\MSIXPackages\$($packageFolder.Name)"
        "version" = $packageVersion
    }
}

#send the actual API request to register the package in the hostpool using the pipeline serviceprincipal
try{
    $context = [Microsoft.Azure.Commands.Common.Authentication.Abstractions.AzureRmProfileProvider]::Instance.Profile.DefaultContext
    $token = [Microsoft.Azure.Commands.Common.Authentication.AzureSession]::Instance.AuthenticationFactory.Authenticate($context.Account, $context.Environment, $context.Tenant.Id.ToString(), $null, [Microsoft.Azure.Commands.Common.Authentication.ShowDialog]::Never, $null, "https://management.azure.com")          
    Invoke-RestMethod -Uri "https://management.azure.com/subscriptions/$((get-azcontext).Subscription.id)/resourcegroups/rg-common-$($environment)-weeu-01/providers/Microsoft.DesktopVirtualization/hostPools/vdhp-common-$($environment)-weeu-01/msixPackages/$($packageFolder.Name)?api-version=2021-07-12" -Method PUT -UseBasicParsing -ContentType "application/json" -Body ($apiPostData | convertto-json -Depth 15) -Headers @{"Authorization"="Bearer $($token.AccessToken)"} -ErrorAction Stop
}catch{
    Write-Output $_
    closeCIMSession
    Throw
}
Automation, Azure, Powershell, Security

Easily get access token for Azure Management API

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Wrote this little snippet that assumes a logged in session (Connect-AzAccount) and easily/quickly produces an auth header.

function get-azRMAccessHeader(){
    $profile = [Microsoft.Azure.Commands.Common.Authentication.Abstractions.AzureRmProfileProvider]::Instance.Profile
    $context = Get-AzContext
    $client = New-Object Microsoft.Azure.Commands.ResourceManager.Common.RMProfileClient($profile)

    $header = @{
        "Authorization" = "Bearer $($client.AcquireAccessToken((Get-AzContext).Tenant.TenantId).AccessToken)"
    }
    return $header
}
Azure, AzureAD, Identity, Powershell, Sharepoint Online

Powershell Cert based authentication against the Graph API using a certificate from Keyvault

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In automation scenarios it is common to use a service principal (app based) to work with the Graph API, or in my example, with PNP PowerShell against SharePoint (but both scenario’s work the same).

First, you’d need a client certificate, e.g. like this:

$folder = "c:\users\JosLieben\Desktop"
$cert=New-SelfSignedCertificate -Subject "CN=JOS" -CertStoreLocation "Cert:\CurrentUser\My"  -KeyExportPolicy Exportable -KeySpec Signature -HashAlgorithm "SHA256" -Provider "Microsoft Enhanced RSA and AES Cryptographic Provider"
Export-Certificate -Cert $cert -FilePath "$folder\jos.cer" 
Export-PfxCertificate -Password (ConvertTo-SecureString $clientCertPwd -AsPlainText -Force) -Cert $cert -FilePath "$folder\jos.pfx"

You’d then upload the .cer file as a certificate on your service principal to let Azure AD recognize your cert as a valid ‘password’ for your app registration.

Next you’d upload your .pfx file into Keyvault.

Finally, you can use Powershell to construct an access token for a given scope:

$tenantId = "YOURTENANTID"
$clientId = "YOURCLIENTID"
$scope = "https://graph.microsoft.com/.default" #or, e.g. https://$($tenantName)-admin.sharepoint.com/.default openid profile offline_access
$secret = Get-AzKeyVaultSecret -VaultName "YOURKEYVAULTNAME" -Name cippCert -AsPlainText
$clientCert = New-Object System.Security.Cryptography.X509Certificates.X509Certificate2 -ArgumentList @([Convert]::FromBase64String($secret),"",[System.Security.Cryptography.X509Certificates.X509KeyStorageFlags]::Exportable)

$header = @{
    alg = "RS256"
    typ = "JWT"
    x5t = [System.Convert]::ToBase64String(($clientCert.GetCertHash()))
} | ConvertTo-Json -Compress

$claimsPayload = @{
    aud = "https://login.microsoftonline.com/$tenantId/oauth2/token"
    exp = [math]::Round(((New-TimeSpan -Start ((Get-Date "1970-01-01T00:00:00Z" ).ToUniversalTime()) -End (Get-Date).ToUniversalTime().AddMinutes(2)).TotalSeconds),0)
    iss = $clientId
    jti = (New-Guid).Guid
    nbf = [math]::Round(((New-TimeSpan -Start ((Get-Date "1970-01-01T00:00:00Z" ).ToUniversalTime()) -End ((Get-Date).ToUniversalTime())).TotalSeconds),0)
    sub = $clientId
} | ConvertTo-Json -Compress

$headerjsonbase64 = [Convert]::ToBase64String([System.Text.Encoding]::UTF8.GetBytes($header)).Split('=')[0].Replace('+', '-').Replace('/', '_')
$claimsPayloadjsonbase64 = [Convert]::ToBase64String([System.Text.Encoding]::UTF8.GetBytes($claimsPayload)).Split('=')[0].Replace('+', '-').Replace('/', '_')

$preJwt = $headerjsonbase64 + "." + $claimsPayloadjsonbase64
$toSign = [System.Text.Encoding]::UTF8.GetBytes($preJwt)
$privateKey = $clientCert.PrivateKey
$alg = [Security.Cryptography.HashAlgorithmName]::SHA256
$padding = [Security.Cryptography.RSASignaturePadding]::Pkcs1
$signature = [Convert]::ToBase64String($privateKey.SignData($toSign,$alg,$padding)) -replace '\+','-' -replace '/','_' -replace '='

$jwt = $headerjsonbase64 + "." + $claimsPayloadjsonbase64 + "." + $signature

$Authbody = @{
    'tenant' = $tenantId
    'scope' = $scope
    'client_assertion_type' = 'urn:ietf:params:oauth:client-assertion-type:jwt-bearer'
    'client_id'     = $clientId
    'grant_type'    = 'client_credentials'
    'client_assertion' = $jwt
}        

$accessToken = (Invoke-RestMethod -Method post -Uri "https://login.microsoftonline.com/$($tenantid)/oauth2/v2.0/token" -Body $Authbody -ErrorAction Stop).accesstoken

The token can then be used to used to call Graph. And an example that shows how to use a sharepoint scoped token for the Sharepoint PNP PowerShell moddule:

#use scope: https://$($tenantName)-admin.sharepoint.com/.default

connect-PnPOnline -Url "https://$($tenantName)-admin.sharepoint.com" -AccessToken $accessToken -ReturnConnection
Automation, Azure, Azure Virtual Desktop, EMS, Intune, Powershell

Deallocate Azure AD Joined Azure Virtual Desktop VMs when a user logs off

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When you shut down a VM or log off, the VM isn’t actually deallocated and still costs money.

Bernd wrote a nice guide on how to deallocate a VM when a user logs off, using GPO’s, since combined with Start On Connect the user experience is still pretty decent.

For Intune / Microsoft Endpoint Manager, no solution was known yet. So I base64 encoded Bernd’s solution and wrapped it into a SYSTEM wide scheduled task that is triggered by a security eventlog logoff entry.

Deploy this to your VM’s in Intune (either through a user or a machine group) and it’ll ensure users’ VM’s get deallocated when they log off.

This also works on shared VM’s, as it will only deallocate if it is the last user logging off.

You can download/view set-AVDDeallocateOnLogoff.ps1 here.

Automation, Azure, Azure Virtual Desktop, Powershell

Using an automation account for Azure Automated Right Sizing

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The recommended method to run my ADDRS on a schedule is through an Azure Runbook or an Azure DevOps pipeline.

This post describes how to configure an Automation Account to run ADDRS in detailed steps.

  1. Create a resourcegroup:
create addrs resource group

2. Create an automation account in the resource group you just created:

create addrs automation account

3. Use system assigned managed identity

use system assigned managed identity

4. Accept further defaults and when created click Go to resource:

go to resource ADDRS

5. Under the Identity option, click Azure Role Assignments:

Go to azure role assignments

6. Be sure to select the same subscription your Virtual Machines are in:

7. If you wish to scope permissions more specifically (always recommended), at minimum you’ll need to assign Virtual Machine Contributor to the resource group(s) containing your VM’s and Log Analytics Reader on your log analytics workspace.

8. Now create a runbook in your new automation account:

create runbook
select runbook type and click Create

9. After clicking Create, copy paste the following example code in the editor and uncomment either set-rsgRightSize or set-vmRightSize depending on which way you’re using the module. Update the RSG or VM name you’re targetting and update the workspaceId

Connect-AzAccount -Identity

#set-rsgRightSize -targetRSG "rg-avd-01" -workspaceId "7ccd0949-2fd4-414e-b58c-c013cc6e445d"

#set-vmRightSize -targetVMName "azvm01"  -workspaceId "7ccd0949-2fd4-414e-b58c-c013cc6e445d"

10. Save & Publish

11. Go to modules and click browse gallery, search for ADDRS:

browse PS gallery for modules
Search for ADDRS
Select ADDRS
Select runtime v 7.1 and import

12. Wait for the import to complete. If it fails, check if you have installed the 7.1 versions of these requires modules, install if needed and try again:

  • Az.Compute
  • Az.OperationalInsights
  • Az.Resources
  • Az.Accounts

13. Run the runbook to test, or link it to a schedule:

link runbook to a new schedule
Create a schedule as desired and press create.

14. if you want to use a schedule different from weekly, make sure to also add the -measurePeriodHours parameter to match, and if you use maintenance windows, include those as well as described in the module manual.