disk-consolidation.ps1

#Requires -Version 5.0 -Modules VMware.VimAutomation.Core

<#
.SYNOPSIS
  Check vCenter(s) for any VMs with disks needing consolidation, attempting to consolidate any it finds.

.DESCRIPTION
  Kicks off ConsolidateVMDisks_Tasks for any VirtualMachine objects it finds needing consolidation. Emails a report detailing any it successfully consolidates, has errors with, or excluded due.

.NOTES
  Since we don't specify a credential pair to connect with, it will attempt to connect as the current script environment's user.
  Due to the current architecture of the code, if the -WhatIf switch is used, the Disconnect-VIServer command will not execute. To workaround this, I added "-WhatIf:$false" to that line.
#>
[CmdletBinding(SupportsShouldProcess = $true)]
Param(
  # List of VMs to exclude from disk consolidation
  [string[]]
  $ExcludedVMs,

  # Email address the report will be sent to.
  [ValidateNotNullOrEmpty()]
  [string[]]
  $ToAddress,

  # Email address the report will show as from.
  [string]
  $FromAddress
)

function Write-Log {
<#
.SYNOPSIS
  Logs messages to a file

.DESCRIPTION
  Receives messages and logs them to an output file.

.EXAMPLE
  Write-Log -Message "Write this to the log" -Path "C:\Temp\LogFile.log"

.NOTES
  Uses the variable $LogPath as the default value for Path
#>
  [CmdletBinding()]
  param (
    # The message to be written
    [Parameter(Mandatory = $true)]
    [string]
    $Message,

    # File path of the log file. Default value is $LogPath, if set.
    [ValidateNotNullOrEmpty()]
    [string]
    $Path = $LogPath
  )
  begin {
    $ConfirmPreference = 'None'
  }

  process {
    Write-Verbose $Message
    Add-Content -Path $Path -Value "[$(Get-Date -Format 'yy:MM:dd-hh:mm:ss')] $Message"
  }
}

function Add-EmailBodyContent {
<#
.SYNOPSIS
  Generates a formatted text block using a heading and list of child items.

.DESCRIPTION
  The Add-EmailBodyContent cmdlet accepts a SectionHeader and array of ChildItems and uses them to generate a formatted block of text.
  The SectionHeader is listed on the first line, with each of the ChildItems indented on subsequent lines.

.EXAMPLE
  PS> Add-EmailBodyContent -SectionHeader 'Cars' -ChildItems $('car1','car2','car3')
  Cars:
          car1
          car2
          car3
#>
  [CmdletBinding()]
  param (
    # The header for the text block.
    [Parameter(Mandatory)]
    [string]
    $SectionHeader,

    # List of items to appear indented under the SectionHeader
    [Parameter(Mandatory)]
    [string[]]
    $ChildItems
  )

  process {
    Write-Output "$($SectionHeader):`n"
    foreach ($item in $ChildItems) {
      Write-Output "`t$($item)`n"
    }
    Write-Output "`n"
  }
}

function Invoke-DiskConsolidation {
<#
.SYNOPSIS
  Start disk consolidation tasks for each VirtualMachine in View

.DESCRIPTION
  Start disk consolidation tasks for each of the VirtualMachine managed objects in View. These tasks are non-blocking and will execute in parallel.

.EXAMPLE
  PS> $TaskList = Invoke-DiskConsolidation -View $view -ExcludedVMs $ExcludedVMs
  Returns a Hashtable ($TaskList) containing the task objects and VM names

.NOTES
  The tasks created by the ConsolidateVMDisks_Task method are non-blocking, meaning it will not wait for completion before continuing.
  There is another VirtualMachine method, ConsolidateVMDisks, which waits for the consolidation to complete before continuing.

.OUTPUTS
  [System.Collections.Hashtable] Containing tasks and the VM names
#>
  [CmdletBinding(SupportsShouldProcess = $true)]
  param (
    # List of vSphere View VirtualMachine objects representing the VMs that will have their disks consolidated.
    [VMware.Vim.ViewBase[]]
    $View,

    # List of VMs to exclude from consolidation
    [string[]]
    $ExcludedVMs
  )

  begin {
    $View = $View | Where-Object {$_.Name -notin $ExcludedVMs}
    $TaskList = @{}
  }

  process {
    foreach ($VirtualMachineObj in $View) {
      Write-Log "Kicking off consolidation for $($VirtualMachineObj.Name)"
      if ($PSCmdlet.ShouldProcess($VirtualMachineObj.Name)) {
        $TaskList[(Get-Task -Id $VirtualMachineObj.ConsolidateVMDisks_Task()).Id] = $VirtualMachineObj.Name
      }
    }
  }

  end {
    Write-Output $TaskList
  }
}


##### Variables #####
$vCentersList = @('vcenter1.example.com', 'vcenter2.example.com')
$LogPath = "$env:SystemDrive\Windows\Temp\Disk_Consolidation.log"

$ExcludedVMs = @('exclude-this-vm')

# Used when determining if consolidation succeeded/failed
$TaskList = @{}
$SuccessfulVMs = @()
$ErrorVMs = @()

# Used in report generation
$EmailBody = ''
#####################

foreach ($vCenter in $vCentersList) {
  try {
    Connect-VIServer $vCenter -ErrorAction Stop | Out-Null
    Write-Log "Connected to $($vCenter)"
  } catch {
    Write-Log "Error connecting to $($vCenter)"
  }
}

if ($Global:DefaultVIServers.Count -gt 0) {
  $VirtualMachineView = Get-View -ViewType VirtualMachine -Property Name, Runtime.ConsolidationNeeded -Filter @{'Runtime.ConsolidationNeeded' = 'True' }
  $TaskList = Invoke-DiskConsolidation -View $VirtualMachineView -ExcludedVMs $ExcludedVMs

  do {
    foreach ($Task in @($TaskList.Keys)) {
      switch (Get-Task -Id $Task) {
        {$_.State -eq 'Success'} {
          Write-Log "Successfully consolidated $($TaskList.$Task)."
          $SuccessfulVMs += $TaskList.$Task
          $TaskList.Remove($Task)
        }
        {$_.State -eq 'Error'} {
          Write-Log "Error consolidating $($TaskList.$Task)."
          $ErrorVMs += $TaskList.$Task
          $TaskList.Remove($Task)
        }
        {$_.State -eq 'Running'} {
          Write-Log "Waiting for $($Task) ($($TaskList.$Task)) to complete."
          Start-Sleep -Seconds 5
        }
        Default { Start-Sleep -Seconds 5 }
      }
    }
  } while ($TaskList.Count -gt 0)

  if ($SuccessfulVMs -gt 0) {
    $EmailBody += Add-EmailBodyContent -SectionHeader "Successfully Consolidated" -ChildItems $SuccessfulVMs
  }
  if ($ErrorVMs -gt 0) {
    $EmailBody += Add-EmailBodyContent -SectionHeader "Error Consolidating" -ChildItems $ErrorVMs
  }
  if ($ExcludedVMs -gt 0) {
    $EmailBody += Add-EmailBodyContent -SectionHeader "Excluded From Consolidation" -ChildItems $ExcludedVMs
  }

  # If $EmailBody is still empty, include a warning
  if ($EmailBody -eq '') {
    $EmailBody += Add-EmailBodyContent -SectionHeader "Warning, no VMs processed. Check the logs." -ChildItems "$($LogPath)"
  }

  Write-Log -Message "Sending email report. From:$($FromAddress) To:$($ToAddress)"

  Send-MailMessage -From $FromAddress -To $ToAddress -SmtpServer 'mailserver.example.com' -Subject 'Automated Disk Consolidation Results' -Body $EmailBody

  Disconnect-VIServer * -Confirm:$false -WhatIf:$false
}