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#require -version 3.0
<#
.SYNOPSIS
Toggle the disk cache for Azure OS disks
.DESCRIPTION
Using REST API calls
.PARAMETER azid
The relative URI of the Azure VM
.PARAMETER AZtenantId
The azure tenant ID
.PARAMETER cachingMode
The disk caching mode to set or to report only
.NOTES
Version: 0.1
Author: Guy Leech, BSc based on code from Esther Barthel, MSc
Creation Date: 2023-11-28 Guy Leech Script born
Updated: 2024-01-05 Guy Leech Added / support to cachingMode. Removed unused code
#>
[CmdletBinding()]
Param
(
## TODO can we pass disk ID for a disk object - https://controlup.slack.com/archives/C02GE45FW1X/p1701187902094239
[string]$AZid ,## passed by CU as the URL to the VM minus the FQDN
[string]$AZtenantId ,
[ValidateSet('None','ReadOnly', 'Read/Only','ReadWrite','Read/Write','ReportOnly','Report/Only')]
[string]$cachingMode = 'ReportOnly'
)
$VerbosePreference = $(if( $PSBoundParameters[ 'verbose' ] ) { $VerbosePreference } else { 'SilentlyContinue' })
$DebugPreference = $(if( $PSBoundParameters[ 'debug' ] ) { $DebugPreference } else { 'SilentlyContinue' })
$ErrorActionPreference = $(if( $PSBoundParameters[ 'erroraction' ] ) { $ErrorActionPreference } else { 'Stop' })
$ProgressPreference = 'SilentlyContinue'
[int]$outputWidth = 400
if( ( $PSWindow = (Get-Host).UI.RawUI ) -and ( $WideDimensions = $PSWindow.BufferSize ) )
{
$WideDimensions.Width = $outputWidth
$PSWindow.BufferSize = $WideDimensions
}
[string]$computeApiVersion = '2023-07-01'
[string]$baseURL = 'https://management.azure.com'
[string]$credentialType = 'Azure'
[hashtable]$script:apiversionCache = @{}
$warnings = New-Object -TypeName System.Collections.Generic.List[string]
Write-Verbose -Message "AZid is $AZid"
#region AzureFunctions
function Get-AzSPStoredCredentials {
<#
.SYNOPSIS
Retrieve the Azure Service Principal Stored Credentials
.EXAMPLE
Get-AzSPStoredCredentials
.CONTEXT
Azure
.NOTES
Version: 0.1
Author: Esther Barthel, MSc
Creation Date: 2020-08-03
Purpose: WVD Administration, through REST API calls
#>
[CmdletBinding()]
Param
(
[Parameter(Mandatory=$true)]
[string]$system ,
[string]$tenantId
)
[string]$strAzSPCredFolder = [System.IO.Path]::Combine( [environment]::GetFolderPath('CommonApplicationData') , 'ControlUp' , 'ScriptSupport' )
$AzSPCredentials = $null
Write-Verbose -Message "Get-AzSPStoredCredentials $system $tenantId"
[string]$credentialsFile = $(if( -Not [string]::IsNullOrEmpty( $tenantId ) )
{
[System.IO.Path]::Combine( $strAzSPCredFolder , "$($env:USERNAME)_$($tenantId)_$($System)_Cred.xml" )
}
else
{
[System.IO.Path]::Combine( $strAzSPCredFolder , "$($env:USERNAME)_$($System)_Cred.xml" )
})
Write-Verbose -Message "`tCredentials file is $credentialsFile"
If (Test-Path -Path $credentialsFile)
{
try
{
if( ( $AzSPCredentials = Import-Clixml -Path $credentialsFile ) -and -Not [string]::IsNullOrEmpty( $tenantId ) -and -Not $AzSPCredentials.ContainsKey( 'tenantid' ) )
{
$AzSPCredentials.Add( 'tenantID' , $tenantId )
}
}
catch
{
Write-Error -Message "The required PSCredential object could not be loaded from $credentialsFile : $_"
}
}
Elseif( $system -eq 'Azure' )
{
## try old Azure file name
$azSPCredentials = Get-AzSPStoredCredentials -system 'AZ' -tenantId $AZtenantId
}
if( -not $AzSPCredentials )
{
Write-Error -Message "The Azure Service Principal Credentials file stored for this user ($($env:USERNAME)) cannot be found at $credentialsFile.`nCreate the file with the Set-AzSPCredentials script action (prerequisite)."
}
return $AzSPCredentials
}
function Get-AzBearerToken {
<#
.SYNOPSIS
Retrieve the Azure Bearer Token for an authentication session
.EXAMPLE
Get-AzBearerToken -SPCredentials <PSCredentialObject> -TenantID <string>
.CONTEXT
Azure
.NOTES
Version: 0.1
Author: Esther Barthel, MSc
Creation Date: 2020-03-22
Updated: 2020-05-08
Created a separate Azure Credentials function to support ARM architecture and REST API scripted actions
2022-06-28
Added -scope as argument so can authenticate for Graph as well as Azure
2022-07-04
Added optional retry mechanism in case of transient Azure errors
Purpose: WVD Administration, through REST API calls
#>
[CmdletBinding()]
Param(
[Parameter(Mandatory=$true, HelpMessage='Azure Service Principal credentials' )]
[ValidateNotNullOrEmpty()]
[System.Management.Automation.PSCredential] $SPCredentials,
[Parameter(Mandatory=$true, HelpMessage='Azure Tenant ID' )]
[ValidateNotNullOrEmpty()]
[string] $TenantID ,
[Parameter(Mandatory=$true, HelpMessage='Authentication scope' )]
[ValidateNotNullOrEmpty()]
[string] $scope
)
## https://docs.microsoft.com/en-us/azure/active-directory/develop/v2-oauth2-client-creds-grant-flow
[string]$uri = "https://login.microsoftonline.com/$TenantID/oauth2/v2.0/token"
[hashtable]$body = @{
grant_type = 'client_credentials'
client_Id = $SPCredentials.UserName
client_Secret = $SPCredentials.GetNetworkCredential().Password
scope = "$scope/.default"
}
[hashtable]$invokeRestMethodParams = @{
Uri = $uri
Body = $body
Method = 'POST'
ContentType = 'application/x-www-form-urlencoded'
}
Invoke-RestMethod @invokeRestMethodParams | Select-Object -ExpandProperty access_token -ErrorAction SilentlyContinue
}
[hashtable]$script:cachedApiVersions = @{}
[int]$script:versionCacheHits = 0
function Invoke-AzureRestMethod {
[CmdletBinding()]
Param(
[Parameter( Mandatory=$true, HelpMessage='A valid Azure bearer token' )]
[ValidateNotNullOrEmpty()]
[string]$BearerToken ,
[string]$uri ,
[ValidateSet('GET','POST','PUT','DELETE','PATCH')] ## add others as necessary
[string]$method = 'GET' ,
$body , ## not typed because could be hashtable or pscustomobject
[string]$propertyToReturn = 'value' ,
[string]$contentType = 'application/json' ,
[switch]$norest ,
[switch]$newestApiVersion ,
[switch]$oldestApiVersion ,
[string]$type , ## help us with looking up API versions & caching
[int]$retries = 0 ,
[int]$retryIntervalMilliseconds = 2500
)
[hashtable]$header = @{
'Authorization' = "Bearer $BearerToken"
}
if( ! [string]::IsNullOrEmpty( $contentType ) )
{
$header.Add( 'Content-Type' , $contentType )
}
[hashtable]$invokeRestMethodParams = @{
Uri = $uri
Method = $method
Headers = $header
}
if( $PSBoundParameters[ 'body' ] )
{
## convertto-json converts certain characters to codes so we convert back as Azure doesn't like them
$invokeRestMethodParams.Add( 'Body' , (( $body | ConvertTo-Json -Depth 20 ) -replace '\\u003e' , '>' -replace '\\u003c' , '<' -replace '\\u0027' , '''' -replace '\\u0026' , '&' ))
}
$responseHeaders = $null
if( $PSVersionTable.PSVersion -ge [version]'7.0.0.0' )
{
$invokeRestMethodParams.Add( 'ResponseHeadersVariable' , 'responseHeaders' )
}
[bool]$correctedApiVersion = $false
if( $newestApiVersion -or $oldestApiVersion )
{
if( $uri -match '\?api\-version=20\d\d-\d\d-\d\d' )
{
$warnings.Add( "Uri $uri already has an api version" )
$correctedApiVersion = $true
}
else
{
[string]$apiversion = '42' ## force error which will return list of valid api versions
## see if we have cached entry already for this provider and use that to save a REST call
if( [string]::IsNullOrEmpty( $type ) -and $uri -match '\w/providers/([^/]+/[^/]+)\w' )
{
$type = $Matches[ 1 ]
}
if( -Not [string]::IsNullOrEmpty( $type ) -and ( $cached = $script:apiversionCache[ $type ] ))
{
$correctedApiVersion = $true
$apiversion = $cached
$script:versionCacheHits++
}
$invokeRestMethodParams.uri += "?api-version=$apiversion"
}
}
else
{
$correctedApiVersion = $true
}
[string]$lastURI = $null
## cope with pagination where get 100 results at a time
do
{
[datetime]$requestStartTime = [datetime]::Now
$thisretry = $retries
$error.Clear()
$exception = $null
do
{
$exception = $null
$result = $null
try
{
if( $norest )
{
$result = Invoke-WebRequest @invokeRestMethodParams
}
else
{
$result = Invoke-RestMethod @invokeRestMethodParams
}
}
catch
{
if( ( $_ | Select-Object -ExpandProperty ErrorDetails | Select-Object -ExpandProperty Message | ConvertFrom-Json | Select-Object -ExpandProperty error -ErrorAction SilentlyContinue | Select-Object -ExpandProperty message) -match 'for type ''([^'']+)''\. The supported api-versions are ''([^'']+)''')
{
[string]$requestType = $Matches[ 1 ]
[string[]]$apiVersionList = $Matches[2] -split ',\s?'
## 2021-12-01
[datetime[]]$apiversions =@( $apiVersionList | Where-Object { $_ -notmatch '(preview|beta|alpha)$' } ) | Sort-Object
if( $correctedApiVersion )
{
## we have already tried to correct the api version but sometimes there is a sub-provider that we can't easily determine
## https://management.azure.com//subscriptions/<subsriptionid>/resourceGroups/WVD/providers/Microsoft.Automation/automationAccounts/automation033926z?api-version
## and
## https://management.azure.com//subscriptions/<subscriptionid>/resourceGroups/WVD/providers/Microsoft.Automation/automationAccounts/automation033926z/runbooks/inputValidationRunbook?
## where latter provider is AutomationAccounts/
}
[int]$apiVersionIndex = $(if( $newestApiVersion ) { -1 } else { 0 } ) ## pick first or last version from sorted array
[string]$apiversion = $(Get-Date -Date $apiversions[ $apiVersionIndex ] -Format 'yyyy-MM-dd')
$invokeRestMethodParams.uri = "$uri`?api-version=$apiversion"
## seems to be too simplistic eg /WVD/providers/Microsoft.Automation/automationAccounts/automation033926z/runbooks/ is type 'automationAccounts/runbooks' not '/Microsoft.Automation/automationAccounts'
##if( $uri -match '\w/providers/([^/]+/[^/]+)\w' )
if( $true )
{
try
{
$script:apiversionCache.Add( $type , $apiversion )
}
catch
{
## already have it
$null
}
}
$correctedApiVersion = $true
$exception = $true ## so we don't break out of loop
$thisretry++ ## don't count this as a retry since was not a proper query
$error.Clear()
}
else
{
$exception = $_
if( $thisretry -ge 1 ) ## do not sleep if no retries requested or this was the last retry
{
Start-Sleep -Milliseconds $retryIntervalMilliseconds
}
}
}
if( -not $exception )
{
break
}
} while( --$thisretry -ge 0)
## $result -eq $null does not mean there was an exception so we need to track that separately to know whether to throw an exception here
if( $exception )
{
## last call gave an exception
Throw "Exception $($exception.ToString()) originally occurred on line number $($exception.InvocationInfo.ScriptLineNumber) for uri $($invokeRestMethodParams.uri)"
}
elseif( $error.Count -gt 0 )
{
$warnings.Add( "Transient errors on request $($invokeRestMethodParams.Uri) - $($error.ToString() | ConvertFrom-Json | Select-Object -ExpandProperty error|Select-Object -ExpandProperty message)" )
}
$lastURI = $invokeRestMethodParams.uri
if( -not [String]::IsNullOrEmpty( $propertyToReturn ) )
{
$result | Select-Object -ErrorAction SilentlyContinue -ExpandProperty $propertyToReturn
}
else
{
$result ## don't pipe through select as will slow script down for large result sets if processed again after return
}
## now see if more data to fetch
if( $result )
{
if( ( $nextLink = $result.PSObject.Properties[ 'nextLink' ] ) -or ( $nextLink = $result.PSObject.Properties[ '@odata.nextLink' ] ) )
{
if( $invokeRestMethodParams.Uri -eq $nextLink.value )
{
$warnings.Add( "Got same uri for nextLink as current $($nextLink.value)" )
break
}
else ## nextLink is different
{
$invokeRestMethodParams.Uri = $nextLink.value
}
}
else
{
$invokeRestMethodParams.Uri = $null ## no more data
}
}
} while( $result -and $null -ne $invokeRestMethodParams.Uri )
}
#endregion AzureFunctions
#region authentication
$azSPCredentials = $null
$azSPCredentials = Get-AzSPStoredCredentials -system $credentialType -tenantId $AZtenantId
If ( -Not $azSPCredentials )
{
Exit 1 ## will already have output error
}
# Sign in to Azure with the Service Principal retrieved from the credentials file and retrieve the bearer token
Write-Verbose -Message "Authenticating to tenant $($azSPCredentials.tenantID) as $($azSPCredentials.spCreds.Username)"
if( -Not ( $azBearerToken = Get-AzBearerToken -SPCredentials $azSPCredentials.spCreds -TenantID $azSPCredentials.tenantID -scope $baseURL ) )
{
Throw "Failed to get Azure bearer token"
}
$azSPCredentials.spCreds = $null
$azSPCredentials = $null
#endregion authentication
if( -Not ( $virtualMachine = Invoke-AzureRestMethod -BearerToken $azBearerToken -uri "$baseURL/$azid`?api-version=$computeApiVersion" -property $null ) )
{
Throw "Failed to get VM for $azid"
}
## get disks
[string]$currentOSdiskCaching = $virtualMachine.properties.storageProfile.osDisk | Select-Object -expandproperty caching -ErrorAction SilentlyContinue
Write-Verbose -Message "Current OS disk caching is $currentOSdiskCaching"
$cachingMode = $cachingMode -replace '[/-]' , '' ## allow dash in name
if( $cachingMode -ieq 'ReportOnly' )
{
Write-Output -InputObject "OS disk caching currently set to $currentOSdiskCaching"
}
elseif( $cachingMode -ieq $currentOSdiskCaching )
{
Write-Warning -Message "OS disk caching already set to $currentOSdiskCaching"
}
else ## change caching
{
## https://docs.microsoft.com/en-us/rest/api/compute/virtual-machines/create-or-update
[hashtable]$body = @{
'location' = $virtualMachine.location
'properties' = @{
'storageProfile' = @{
'OSdisk' = @{
'caching' = $cachingMode
}
}
}
}
if( -Not ( $changedDisk = Invoke-AzureRestMethod -BearerToken $azBearerToken -uri "$baseURL/$azid/?api-version=$computeApiVersion" -property $null -body $body -method PUT ) )
{
Write-Error -Message "Error when changing $($virtualMachine.Name) OS disk caching from $currentOSdiskCaching to $cachingMode"
}
elseif( $changedDisk.properties.storageprofile.OSdisk.caching -ne $cachingMode )
{
Write-Error -Message "Failed to change from $currentOSdiskCaching to $cachingMode, it is now $($changedDisk.properties.storageprofile.OSdisk.caching)"
}
else
{
Write-Output -InputObject "Disk caching changed from $currentOSdiskCaching to $cachingMode ok"
}
}