Get-AzurevmBackup.ps1

<#
.Synopsis
   Given a VM OS disk backed up by the Backup-AzureVM.ps1 script, list all of the backups.
.DESCRIPTION
  List all of the backups on the blob store of the given VM, using the naming convention.
  Please note the results are not sorted, and to discover the order of the backups.

  The backups are as copies of the backing disk blob, with the name convention:
   <Name of the backing blob of the OS disk, without the .vhd extension>_v_<serviceName>-<vmName>_b_<date in yyyy-mm-dd format>-<backup number of the day>.vhd"
.EXAMPLE
    Get the backups of an existing VM, querying the same storage account the VMs disk is kept.
   .\Get-AzurevmBackup.ps1 -ServiceName AService -Name vmName

   Get the backups of an existing VM, querying the specified storage account.
   .\Get-AzurevmBackup.ps1 -FindInStorage -ServiceName AService -Name vmName -StorageAccountName storageaccount
.INPUTS
   None
.OUTPUTS
   Hashtable of compressed backup number in the form of yyyymmdd<dailybackupnumber>
#>
    Param
    (
        # Service the VM is running on
        [Parameter(Mandatory=$true, ParameterSetName="FindInStorage")]
        [switch]
        $FindInStorage, 
        
        # Service the VM is running on
        [Parameter(Mandatory=$true, ParameterSetName="UseVMsStorage")]
        [Parameter(ParameterSetName="FindInStorage")]
        [String]
        $ServiceName, 

        # Name of the VM
        [Parameter(Mandatory=$true, ParameterSetName="UseVMsStorage")]
        [Parameter(ParameterSetName="FindInStorage")]
        [String]
        $Name,

        # Name of the storage account for the backup blobs
        [Parameter(Mandatory=$true, ParameterSetName="FindInStorage")]        
        [String]
        $StorageAccountName,

        # Name of the storage account container for the backup blobs
        [Parameter(Mandatory=$false, ParameterSetName="FindInStorage")]
        [String]
        $StorageAccountContainer = "vhds"
    )

    $currentAzureSubscription = Get-AzureSubscription -Current
    $currentStorageAccountName = $currentAzureSubscription.CurrentStorageAccount

    if ($PSCmdlet.ParameterSetName -ne "FindInStorage")
    {
      $vm = Get-AzureVM -ServiceName $ServiceName -Name $Name -ErrorAction SilentlyContinue

        $containerName = ""
        $diskBlobName = ""
        if ($vm -eq $null)
        {
            Write-Warning "A virtual machine with name $Name on $ServiceName does not exist, current storage account on the subscription will be used."
            $StorageAccountName = $currentStorageAccountName
        }
        else
        {
            $osDiskMediaLinkUri = [System.Uri]$vm.VM.OSVirtualHardDisk.MediaLink

            if ($osDiskMediaLinkUri.Segments.Count -gt 3)
            {
                throw "Disk containers only one level deep supported"
            }

            # If it is a 3 part segment, first part willbe / second will be the container name, and third part will be the blob name
            $StorageAccountContainer = $osDiskMediaLinkUri.Segments[1].Replace("/","")
            $diskBlobName = $osDiskMediaLinkUri.Segments[2]

            $StorageAccountName = $osDiskMediaLinkUri.Host.Split(".")[0]

            # Change the current storage account
            if ($StorageAccountName -ne $currentStorageAccountName)
            {
                Set-AzureSubscription -SubscriptionName $currentAzureSubscription.SubscriptionName -CurrentStorageAccount $StorageAccountName
            }
        }
    }
    else
    {
        # Change the current storage account
        if ($StorageAccountName -ne $currentStorageAccountName)
        {
            Set-AzureSubscription -SubscriptionName $currentAzureSubscription.SubscriptionName -CurrentStorageAccount $StorageAccountName
        }
    }
        
    $backupNameDelimeter = "_b_"
    $diskDelimeter = "_d_"

    $existingBackups = Get-AzureStorageBlob -Container $StorageAccountContainer | 
        Where-Object {$_.Name -match $(".*" + $ServiceName + "-" + $Name + $backupNameDelimeter + "[0-9][0-9]" + $diskDelimeter + "[0-9]{4}-[0-9]{2}-[0-9]{2}-[0-9]{4}\.vhd$")} | 
        Select-Object Name

    $foundBackups = @()

    if($existingBackups -ne $null)
    {
        foreach ($existingBackup in $existingBackups)
        {
            $parts = $existingBackup.Name -split $backupNameDelimeter
            if ($parts.Count -ne 2)
            {
                throw "Unexpected backup format for blob name $existingBackup"
            }

            $backupPart = ""
            $vmParts = $parts[0] -split "-"
            if ($parts[1].Endswith(".vhd"))
            {
                $backupPart = $parts[1].Substring(0, $parts[1].Length - 4)
            }
            else
            {
                $backupPart = $parts[1]
            }
            
            $backupParts = $backupPart -split $diskDelimeter
            if ($backupParts.Count -ne 2)
            {
                throw "The backup name does not conform to the naming convention."
            }
            $diskNumber = $backupParts[0]

            $backupParts = $backupParts[1] -split "-"
            if ($vmParts.Count -ne 2 -and $backupParts.Count -ne 4)
            {
                throw "The backup name does not conform to the naming convention."
            }

            $objBackup = New-Object System.Object
            $objBackup | Add-Member -type NoteProperty -name ServiceName -value $vmParts[0]
            $objBackup | Add-Member -type NoteProperty -name VmName -value $vmParts[1]
            $objBackup | Add-Member -type NoteProperty -name BackupDate -value $($backupParts[1] + "/" + $backupParts[2] + "/" + $backupParts[0])
            $objBackup | Add-Member -type NoteProperty -name BackupNumber -value $backupParts[3]
            $objBackup | Add-Member -type NoteProperty -name BlobName -value $existingBackup.Name
            $objBackup | Add-Member -type NoteProperty -name BackupId -value ([Int64]$($backupParts[0] + $backupParts[1] + $backupParts[2] + $backupParts[3]))

            $foundBackups += $objBackup
        }
    }

    # Restore the original CurrentStorageAccount setting
    Set-AzureSubscription -SubscriptionName $currentAzureSubscription.SubscriptionName -CurrentStorageAccount $currentStorageAccountName

    $foundBackups | Sort-Object -Property BackupId