PowerShell Workflow中Azure VM脚本报unexpected Token错误，求修正

Let's break down the issues in your script and fix them step by step:

1. Immediate Syntax Error Fix #

The error Unexpected Token in Expression or Statement on the line $tags2 ['ShutdownSchedule_AllowStop'] = "$False"; comes down to whitespace strictness in PowerShell Workflows. Unlike regular PowerShell, Workflows don't allow spaces between a variable and its indexing brackets.

Change this:

$tags2 ['ShutdownSchedule_AllowStop'] = "$False";

To this:

$tags2['ShutdownSchedule_AllowStop'] = $false; # Use boolean $false instead of string "$False" for better compatibility

Note: Using the boolean $false instead of a string "$False" is better practice, as Azure resources expect native boolean values for tag fields when applicable.

2. Additional Logic & Scope Issues #

Your script has a few other hidden problems that will prevent it from working correctly even after fixing the syntax error:

a. Incorrect Pipeline Variable Usage #

Inside your ForEach ($vm in $vms) loop, you're using $_.Tags—but $_ (the pipeline automatic variable) doesn't exist here. Since you're iterating with a named variable $vm, you need to reference $vm.Tags instead.

b. Misplaced Set-AzureRmResource Command #

You're calling Set-AzureRmResource outside the inner VM loop, which means it will only apply tag changes to the last VM processed in the loop. Move this command inside the ForEach ($vm in $vms) block to update every VM's tags.

c. Parallel Loop Variable Scope #

When using ForEach -Parallel in a Workflow, you need to ensure the variable containing your VM list is accessible in the parallel execution scope. First, collect all target VMs into a single array outside the parallel loop, then use the $Using: scope modifier to reference it from within the parallel block.

d. Handling VMs with No Existing Tags #

If a VM has no existing tags, $vm.Tags will be $null, which will cause errors when trying to modify it. We'll add a check to create an empty hashtable in this case.

Fixed Complete Script #

workflow Set-AzureRmTags-and-Start {
    [CmdletBinding()]
    Param(
        [Parameter(Mandatory=$True)]
        [string]$VmRG
    )

    $Start = Get-Date
    Write-Output "Start Time: $Start"

    # Collect all matching resource groups
    $VmRGs = Get-AzureRmResourceGroup | Where-Object { $_.ResourceGroupName -like "*$VmRG*" }
    
    # Initialize array to hold all VMs for parallel startup later
    $allVMs = @()

    foreach ($rg in $VmRGs) {
        $VMs = Get-AzureRmVM -ResourceGroupName $rg.ResourceGroupName
        $allVMs += $VMs

        ForEach ($vm in $VMs) {
            # Handle VMs with no existing tags by creating an empty hashtable
            $tags2 = if ($vm.Tags) { $vm.Tags.Clone() } else { @{} }
            # Update the tag with a boolean value
            $tags2['ShutdownSchedule_AllowStop'] = $false;
            
            # Apply tag changes to the current VM
            Set-AzureRmResource -ResourceName $vm.Name `
                                -ResourceGroupName $vm.ResourceGroupName `
                                -ResourceType "Microsoft.Compute/virtualMachines" `
                                -Tag $tags2 `
                                -Force `
                                -Verbose
        }
    }

    $Middle = Get-Date
    Write-Output "Time Taken To Assign Tags: $((Get-Date) - $Start).Minutes Minutes"

    # Parallel VM startup using $Using: to access the allVMs array from workflow scope
    ForEach -Parallel ($vm in $Using:allVMs) {
        Start-AzureRmVM -Name $vm.Name `
                        -ResourceGroupName $vm.ResourceGroupName `
                        -Verbose `
                        -Confirm:$false
    }

    $End = Get-Date
    Write-Output "Time Taken To Start VMs: $((Get-Date) - $Middle).Minutes Minutes"
    Write-Output "Total Time Taken: $((Get-Date) - $Start).Minutes Minutes"
}

Key Changes Explained #

• Fixed the whitespace in hashtable indexing and switched to native boolean $false.
• Replaced $_.Tags with $vm.Tags to correctly reference the current VM's tags.
• Moved Set-AzureRmResource inside the VM loop to ensure every VM gets updated tags.
• Collected all VMs into $allVMs and used $Using:allVMs to make the array accessible in the parallel loop.
• Added logic to handle VMs with no existing tags, preventing null reference errors.

内容的提问来源于stack exchange，提问作者Norrin Rad