How to pass multiple parameters in a function in Powershell? - azure

Question

I am trying to run a Powershell script for a runbook in an automation account in Azure. I am using a function to pass multiple parameters. The runbook is for restoring disks of VM. However from the code structure that I am using it doesn't seem like I can pass in more than 1 Resource Name. How do I restructure this code or how do I frame my function or anyone of the lines in the script in order to pass more than one Resource Name (VM names in this case) ?
Currently I can pass only one Resource Name in the function but I need to pass two VM names.
function DiskRestore($ResourceName, $storageAccount)
{
try
{
.....
.....
.....
$resources = Get-AzureRmResource -ResourceGroupName"samplerg" -ResourceName $ResourceName
.....
.....
.....
$restorejob = Restore-AzureRmRecoveryServicesBackupItem -RecoveryPoint $rp[0] -StorageAccountName $storageAccount -StorageAccountResourceGroupName "samplerg"
.....
.....
.....
}
}
DiskRestore -ResourceName "samplevm01" -storageAccount "samplesa01"
So in the above function how can I pass one more VM name apart from samplevm01. How can I pass samplevm02 ? The storage account remains the same. Thanks in advance.

Answer 1

As commented by Vesper, change the parameter definition to receive a string array and loop through that array with foreach{..}.
Personally I would extend this a little by putting the parameters in a Param() block to create an 'advanced function'. By doing so, the function automatically gains extra common PowerShell parameters like ErrorAction, Verbose etc.
Also, I would rename the function so it complies with the Verb-Noun naming convention for PowerShell functions.
Something like this:
function Restore-Disk {
[CmdletBinding()]
Param (
[Parameter(Mandatory = $true, Position = 0)]
[string[]]$ResourceName,
[string]$ResourceGroupName = 'samplerg', # add a default name for this parameter
[string]$StorageAccount = 'samplesa01', # add a default name for this parameter
[Parameter(Mandatory = $true)]
$RecoveryPoint
)
foreach ($resource in $ResourceName) {
try {
# .....
# This will only print to the console is the -Verbose parameter is used on the function
Write-Verbose "Retrieve resource '$resource' in group '$ResourceGroupName'"
$resources = Get-AzureRmResource -ResourceGroupName $ResourceGroupName -ResourceName $resource
# .....
Write-Verbose "Restoring data and configuration for group '$ResourceGroupName'"
$restorejob = Restore-AzureRmRecoveryServicesBackupItem -RecoveryPoint $RecoveryPoint -StorageAccountName $StorageAccount -StorageAccountResourceGroupName $ResourceGroupName
# .....
}
catch {}
}
}
# Because the parameters ResourceGroupName and StorageAccount have default values, you do not have to specify them
# in the call to the function unless the are different than the default values.
Restore-Disk -ResourceName "samplevm01","samplevm02" -RecoveryPoint $rp[0] -Verbose

Answer 2

If you want to run the powershell in powershell runbook, you can just pass the vm names in a string type and separated by a comma, like "vm1,vm2,vm3". Then in your runbook code, split the string to array, then in the foreach loop, operates with each vm.
A simple test in powershell runbook:
param([string]$ResourceName,[string]$StorageAccount)
#parse the string to an array
$vms = $ResourceName.split(',')
#implement your logic here
foreach($r in $vms)
{
#output the vm name
$r
}
#output the storage account
$StorageAccount
Pass the parameters and run:
For your code, you can follow the above steps, your code in runbook should look like below:
param([string]$ResourceName,[string]$StorageAccount)
$vms = $ResourceName.split(',')
foreach ($resource in $vms) {
try {
#.....
$resources = Get-AzureRmResource -ResourceGroupName "samplerg" -ResourceName $resource
$restorejob = Restore-AzureRmRecoveryServicesBackupItem -RecoveryPoint $rp[0] -StorageAccountName $StorageAccount -StorageAccountResourceGroupName "samplerg"
#....
}
catch {}
}