TIL: Logging Powershell Parameters

In my current project we provision large and complex Azure environments, subscriptions VMs, networking permissions and all that. Some of the scripts have many many parameters - so in a month it would be nice to see how the script were started and with what parameters. With the cmdlet start-transcript you get all the information what happens in the script as a nice log file. But unfortunately the parameters that were used to start the script are not in there. In this post, I show you how to easily add them to the transcript!

Let’s use the following script:

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Param(
    [Parameter(Mandatory=$True, HelpMessage="The first parameter")]
    [string]$Parameter1, 
    [Parameter(Mandatory=$True, HelpMessage="The second parameter")]
    [string]$Parameter2
)
start-transcript
write-out "Do something"
Start-Sleep -Seconds 3
write-out "Everything worked out!"
Stop-Transcript

After starting this script you will have a nice transcript (yellow part), but it does not contain with what parameters the script was started:

Today I learned (TIL)

So today I learned that you can write them to the transcript with just a few lines:

Param(
    [Parameter(Mandatory=$True, HelpMessage="The first parameter")]
    [string]$Parameter1, 
    [Parameter(Mandatory=$True, HelpMessage="The second parameter")]
    [string]$Parameter2
)
start-transcript

#Export the parameters
write-verbose "Parameters:"
foreach ($p in $PsBoundParameters.GetEnumerator())
{
    write-verbose "`tParameter: $($p.Key) Value: $($p.Value)"
}

write-out "Do something"
Start-Sleep -Seconds 3
write-out "Everything worked out!"
Stop-Transcript

If you do this, you will have a nice transcript that contain the parameters (yellow part):

Why write-verbose you might ask? Then you have the choice when you start the script to log the parameters with -Verbose or to not log them if you dont need them. One little note: values of SecureStrings are not exported.

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