Powershell function Invoke-ScriptBlockWithRetries to execute arbitrary PowerShell code and automatically retry if an exception is thrown

PowerShellUtilities.psm1

function Invoke-ScriptBlockWithRetries
{
	param
	(
		[Parameter(Mandatory = $true, HelpMessage = 'The script block to execute.')]
		[ValidateNotNullOrEmpty()]
		[scriptblock] $ScriptBlock,

		[Parameter(Mandatory = $false, HelpMessage = 'The maximum number of times to retry the script block.')]
		[int] $MaxNumberOfRetries = 5,

		[Parameter(Mandatory = $false, HelpMessage = 'The number of milliseconds to wait between each retry.')]
		[int] $MillisecondsBetweenRetries = 5000,

		[Parameter(Mandatory = $false, HelpMessage = 'A list of error messages that should not be retried. If any part of the exception or error details match one of these messages, the script block will not be retried.')]
		[string[]] $ErrorMessagesToNotRetry = @()
	)

	[int] $numberOfAttempts = 0
	while ($true)
	{
		try
		{
			Invoke-Command -ScriptBlock $ScriptBlock
			break	# Break out of the while loop since the command succeeded.
		}
		catch
		{
			$numberOfAttempts++
			[string] $errorMessage = $_.Exception.ToString()
			[string] $errorDetails = $_.ErrorDetails
			Write-Verbose "Script block attempt number '$numberOfAttempts' failed. Will try up to '$($MaxNumberOfRetries + 1)' times.`nException: $errorMessage `nErrorDetails: $errorDetails"

			[bool] $isErrorThatShouldBeRetried = $true
			foreach ($noRetryMessage in $ErrorMessagesToNotRetry)
			{
				if ($errorMessage -like "*$noRetryMessage*" -or $errorDetails -like "*$noRetryMessage*")
				{
					$isErrorThatShouldBeRetried = $false
					break	# Break out of the foreach loop since we found a match.
				}
			}

			[bool] $shouldRetry = $isErrorThatShouldBeRetried -and ($numberOfAttempts -le $MaxNumberOfRetries)
			if ($shouldRetry)
			{
				Write-Verbose "Waiting $MillisecondsBetweenRetries milliseconds before trying again..."
				Start-Sleep -Milliseconds $MillisecondsBetweenRetries
			}
			else
			{
				throw
			}
		}
	}
}

Export-ModuleMember -Function Invoke-ScriptBlockWithRetries

zExamples.ps1

# ========== Examples of how to use module from another ps1 file ==========
using module .\PowerShellUtilities.psm1

# === Example 1 - Action that does not return data ===
[scriptblock] $exampleThatDoesNotReturnData = {
	Stop-Service -Name "SomeService"
}

Invoke-ScriptBlockWithRetries -ScriptBlock $exampleThatDoesNotReturnData


# === Example 2 - Capturing data returned ===
[scriptblock] $exampleThatReturnsData = {
	Invoke-WebRequest -Uri 'https://google.com'
}
$result = Invoke-ScriptBlockWithRetries -ScriptBlock $exampleThatReturnsData -MaxNumberOfRetries 3

if ($result.StatusCode -eq 200)
{
	Write-Output "Success"
}


# === Example 3 - Dealing with failures that still occur even with retries ===
[scriptblock] $exampleThatWillAlwaysFail = {
	Invoke-WebRequest -Uri 'https://SomeAddressThatDoesNotExist.com'
}

try
{
	$result = Invoke-ScriptBlockWithRetries -ScriptBlock $exampleThatWillAlwaysFail
}
catch
{
	$exceptionMessage = $_.Exception.Message
	Write-Error "The following error occurred: $exceptionMessage"
}



# === Example 4 - Specify messages that should not be retried if the exception contains them ===
[scriptblock] $exampleThatReturnsData = {
	Invoke-RestMethod -Uri 'https://google.com'
}

[string[]] $noRetryMessages = @(
	'400 (Bad Request)'
	'401 (Unauthorized)'
)

Invoke-ScriptBlockWithRetries -ScriptBlock $exampleThatReturnsData -ErrorMessagesToNotRetry $noRetryMessages