PowerCLI reboot-cycling script

clear

function Format-Color([hashtable] $Colors = @{}, [switch] $SimpleMatch) {
$lines = ($input | Out-String) -replace "`r", "" -split "`n"
foreach($line in $lines) {
$color = ''
foreach($pattern in $Colors.Keys){
if(!$SimpleMatch -and $line -match $pattern) { $color = $Colors[$pattern] }
elseif ($SimpleMatch -and $line -like $pattern) { $color = $Colors[$pattern] }
}
if($color) {
Write-Host -ForegroundColor $color $line
} else {
Write-Host $line
}
}
}

# Input VM names you want to include in the reboot-cycle, in quotes separated by comma
$testvms =  ""

$i = 0

Write-Host "Running looping-restart script on " -Fore White -NoNewline
write-Host $testvms.Count -Fore Red -NoNewline
Write-Host " VMs on vCenter " -Fore White -NoNewline
Write-Host $global:defaultviserver.name -Fore Green
Write-Host "`n"

while(1)
{

$i = $i+1

# Adjust the sleeptimer to accomodate your environment.
# 20 seconds is enough for VMs on all-flash storage, but should be set higher for VMs on HDD-based storage or for VMs with long boot times.
$sleeptimer = 20

$bmsg = ""
$binfo = ""
$breakmsg = ""

if($i % 3 -eq 0) {$bmsg += " - BOOT FAILURE EXPECTED! - "}
if($i % 3 -eq 0) {$binfo += "(added 10 seconds to reboot-cycle delay)"}
if($i % 3 -eq 0) {$sleeptimer = 30}
if($i % 3 -eq 0) {$breakmsg += "Press Ctrl+C to stop the script"}

Write-Host "Restart #$i" -Fore Cyan -NoNewline
Write-Host "$bmsg" -Fore Red -NoNewline
Write-Host "$binfo" -Fore Magenta

foreach ($vm in $testvms){
    $currenttime = Get-Date -UFormat "%H:%M:%S"

    Restart-VM -VM $vm -RunAsync -Confirm:$false | Out-Null

    Write-Host "[" -Fore Gray -NoNewline
    Write-Host "$currenttime" -Fore White -NoNewline
    Write-Host "]" -Fore Gray -NoNewLine
    Write-Host ": " -Fore White -NoNewline
    Write-Host "Issued restart command to VM " -Fore Yellow -NoNewline
    Write-Host "'$vm'" -Fore Green
    }

Write-Host "$breakmsg" -Fore Red
start-sleep -seconds $sleeptimer
}​