Tag Archives: AWSPowerShell

Get the AWS Noun Prefixes

One of the nice things about the Get-AWSPowerShellVersion cmdlet is the ListServiceVersionInfo switch parameter. It returns properties for the Service (as in the AWS Service offering name), the “Noun Prefix,” and “API Version.” Yes, there really are spaces in those last two property names; however, they’ve been fixed in my function. I had been hoping for an easier way to determine the prefixes used in the AWS cmdlets, and here we have it. I actually considered parsing cmdlet names myself, so a huge thanks to AWS, for making sure that wasn’t necessary.

It’s almost as though this should have been its own cmdlet though — a get the version cmdlet and a get the noun prefixes cmdlet. Therefore, I’ve wrapped this command and its parameter in a quick and easy to use function for my user base. Copy, paste, try it out; it’s all yours. Super simple.

Function Get-AWSNounPrefix {
    The function returns the AWS PowerShell cmdlet noun prefixes, along with the corresponding AWS Service.

    The function returns the AWS PowerShell cmdlet noun prefixes, along with the corresponding AWS Service name. This function utilizes the AWSPowerShell module's Get-AWSPowerShellVersion function.

    -------------------------- EXAMPLE 1 --------------------------
    PS > Get-AWSNounPrefix
    This examples returns all the noun prefixes and their corresponding AWS Service name.

    -------------------------- EXAMPLE 2 --------------------------
    PS > Get-AWSNounPrefix | Where-Object NounPrefix -match 'cf'
    NounPrefix Service            APIVersion
    ---------- -------            ----------
    CF         Amazon CloudFront  2016-09-29
    CFG        AWS Config         2014-11-12
    CFN        AWS CloudFormation 2010-05-15

    This example uses the Where-Object cmdlet and the Match operator to filter the results by the NounPrefix.

    -------------------------- EXAMPLE 3 --------------------------
    PS > Get-AWSNounPrefix | Where-Object Service -like '*formation*'
    NounPrefix Service            APIVersion
    ---------- -------            ----------
    CFN        AWS CloudFormation 2010-05-15

    This example uses the Where-Object cmdlet and the Like operator to filter the results by the service name.

    -------------------------- EXAMPLE 4 --------------------------
    PS > Get-AWSNounPrefix | Where-Object -Property APIVersion -like '2016*' | Sort-Object -Property APIVersion -Descending
    NounPrefix Service                          APIVersion
    ---------- -------                          ----------
    SMS        Amazon Server Migration Service  2016-10-24
    BGT        AWS Budgets                      2016-10-20
    CF         Amazon CloudFront                2016-09-29
    EC2        Amazon Elastic Compute Cloud     2016-09-15
    SNOW       AWS Import/Export Snowball       2016-06-30
    CGIP       Amazon Cognito Identity Provider 2016-04-18
    INS        Amazon Inspector                 2016-02-16
    AAS        Application Auto Scaling         2016-02-06
    MM         AWS Marketplace Metering         2016-01-14
    DMS        AWS Database Migration Service   2016-01-01

    This example uses the Where-Object, and Sort-Object cmdlet, to find services updated in 2016 and sorts by the most recently added and updated.

    Name: Get-AWSNounPrefix
    Author: Tommy Maynard
    Comments: Current version of AWSPowerShell module at the first, last edit:
    Last Edit: 11/18/2016
    Version 1.0
    Param (

    Begin {
        $AWSServices = Get-AWSPowerShellVersion -ListServiceVersionInfo | Sort-Object -Property 'Noun Prefix'
    } # End Begin.

    Process {
        Foreach ($AWSService in $AWSServices) {
                NounPrefix = $AWSService.'Noun Prefix'
                Service = $AWSService.Service
                APIVersion = $AWSService.'API Version'
        } # End Foreach.
    } # End Process.

    End {
    } # End End.
} # End Function: Get-AWSNounPrefix.


Compare AWSPowerShell Versions

Series links: Part I, Part II, Part III (Coming)

Well, I wrote enough example code inside my PowerShell ConsoleHost recently, to write another post. That’s typically how these works. Find something great… write. Find something I hate… write. Most of all, just write. Put it on Twitter and help people learn — someone did it for me once.

Today’s goal was to compare my currently installed version of the AWSPowerShell module with the newest version of the AWSPowerShell module. We’ll do this a bit backwards, and start with obtaining the newest version of the AWSPowerShell Module first. Because AWS has elected to put their module on the PowerShell Gallery — thanks, guys — we don’t have to parse the AWS PowerShell home page. I’m not sure if it’s even there, but luckily for us, it doesn’t need to be, and so I don’t need to try.

PS &gt; Find-Module -Name AWSPowerShell

Version    Name                                Repository           Description
-------    ----                                ----------           -----------    AWSPowerShell                       PSGallery            The AWS Tools for Windows PowerShell lets develo...

PS &gt; (Find-Module -Name AWSPowerShell).Version

Major  Minor  Build  Revision
-----  -----  -----  --------
3      3      9      0

PS &gt; (Find-Module -Name AWSPowerShell).Version.ToString()

Now that we can obtain the version number of the newest release, let’s work on getting the currently installed version number. My first thought was to use Get-AWSPowerShellVersion. It was a mess, but here’s what I did. This cmdlet does not return an object, unfortunately (and should be replaced and/or corrected).

Seriously, we expect that cmdlets and functions will return a usable object, or objects. If we really need additional information stuffed in the results, let’s only include it with the Verbose parameter. Maybe just drop all that text in a file and have Verbose indicate the file to open. Maybe make a secondary cmdlet. Anything really, that doesn’t require that we parse text… which is exactly what I did (at first).

PS &gt; ((Get-AWSPowerShellVersion).Split('`n')[2])[1..7] -join ''
PS &gt; [version](((Get-AWSPowerShellVersion).Split('`n')[2])[1..7] -join '')

Major  Minor  Build  Revision
-----  -----  -----  --------
3      3      0      0

The problem with this approach is that it’s much too exact. It’s grabbing certain characters. What happens when the version is longer than seven characters? We would’ve lost our final zero, if I was still on a previous version, such as,, or Not good enough.

I knew the AWSPowerShell module put something somewhere; every module does. I browsed over to “C:\Program Files (x86)\AWS Tools\PowerShell\AWSPowerShell” to take a look around. Maybe there was something there that would be more reliable. I quickly spotted the module manifest file: AWSPowerShell.psd1. I opened it up in a text editor, and as suspected, there was the version… right inside that beautiful hash table. I closed up the file, and used Test-ModuleManifest inside my ConsoleHost.

PS &gt; $Path = 'C:\Program Files (x86)\AWS Tools\PowerShell\AWSPowerShell\AWSPowerShell.psd1'
PS &gt; Test-ModuleManifest -Path $Path

ModuleType Version    Name                                ExportedCommands
---------- -------    ----                                ----------------
Binary    AWSPowerShell                       {Clear-AWSHistory, Set-AWSHistoryConfiguration, Initialize...

PS &gt; (Test-ModuleManifest -Path $Path).Version

Major  Minor  Build  Revision
-----  -----  -----  --------
3      3      0      0

PS &gt; (Test-ModuleManifest -Path $Path).Version.ToString()

That’s way more reliable. I’d much rather blame AWS if it doesn’t return the correct version, than my parsing against the results of Get-AWSPowerShellVersion. I mean, seriously.

If you’ve been following my writings, then it’ll come as no surprise that I started with the hardest way and overlooked the obvious. I could’ve simply just used Get-Module to return the version; it’s getting its information from the .psd1 file. As obnoxious as this is, it’s keeping me sharp. I get to repeatedly practice what I know, and give my mind time to sort out different resolutions to the same problem. Here’s how I returned the version of the currently installed AWSPowerShell module.

PS &gt; Get-Module -Name AWSPowerShell

ModuleType Version    Name                                ExportedCommands
---------- -------    ----                                ----------------
Binary    AWSPowerShell                       {Add-AASScalableTarget, Add-ACMCertificateTag, Add-ASAAtta...

PS &gt; (Get-Module -Name AWSPowerShell -ListAvailable).Version

Major  Minor  Build  Revision
-----  -----  -----  --------
3      3      0      0

PS &gt; (Get-Module -Name AWSPowerShell -ListAvailable).Version.ToString()

Now I can return both the currently installed version of the AWSPowerShell module, and the newest version of the AWSPowerShell module from the PowerShell Gallery. Before we compare them, notice that in the above examples that I did and didn’t use the -ListAvailable parameter. If you don’t use it, you better be absolutely certain the module has already been imported.

So, let’s get these version numbers into a couple variables and compare them.

PS &gt; $CurrentAWSPSModule = (Get-Module -Name AWSPowerShell -ListAvailable).Version.ToString()
PS &gt; $CurrentAWSPSModule
PS &gt; $NewestAWSPSModule = (Find-Module -Name AWSPowerShell).Version.ToString()
PS &gt; $NewestAWSPSModule
PS &gt; Compare-Object -ReferenceObject $CurrentAWSPSModule -DifferenceObject $NewestAWSPSModule -IncludeEqual

InputObject SideIndicator
----------- -------------     =&gt;     &lt;=

As we can tell, there is a difference between my version and the one in the PowerShell Gallery. I should probably download the newest version. Watch for a follow up to this article, as I may go ahead and write a second part, as I have some other ideas.

More AWS PowerShell Changes Due to Twitter (and Me)

It happened again. My Tweet, that was linked to a post here, became the catalyst for a change in the AWS PowerShell module. I’m 2 for 2. This time, AWS didn’t simply correct the spelling of a parameter name; they wrote a new cmdlet. Remove-EC2Instance works as advertised. It’ll prompt for confirmation before terminating an EC2 instance, unless the -Force parameter is also included with the command. It is flawless. You can always get the newest AWSPowerShell module at http://aws.amazon.com/powershell.

What this didn’t do, however, is fix Stop-EC2Instance. Steve, the individual that spotted this and my last AWS Tweet, and likely made these corrections and additions, said they couldn’t remove the malfunctioning -Terminate parameter from Stop-EC2Intance. For those that didn’t read my last AWS post, the -Terminate parameter never prompted for confirmation before terminating an instance (unless a change has been made since Remove-EC2Instance was released).

I read an interesting article recently that indicated to use termination protection:

Use termination protection for non-auto-scaling instances. Thank me later.
If you have any instances which are one-off things that aren’t under auto-scaling, then you should probably enable termination protection, to stop anyone from accidentally deleting the instance. I’ve had it happen, it sucks, learn from my mistake!”

While it was still quite amazing to get a second change made to the AWSPowerShell module, I’d recommend that everyone continue to be careful with Stop-EC2Instance. Perhaps you can write your own wrapper function, with the same name as the cmdlet (and therefore, it’ll be the default when Stop-EC2Instance is called), that forces confirmation. Then again, you can just use Remove-EC2Instance now. We’ll hope that when people look to terminate an EC2 instance, that they find Remove-EC2Instance before they find the -Terminate parameter in Stop-EC2Instance, such as I would have, had it previously existed. 🙂

AWS Stop-EC2Instance Needs Complimentary Cmdlet

Well, it’s time to try this again: Can a Tweet get another change to the AWSPowerShell module? Maybe you’ve read a recent post about an inconsistent parameter name between the same parameter, in two corresponding cmdlets. One tweet later and that was on its way to being fixed. You can read about that here: http://tommymaynard.com/twitter-reply-hashtag-aws-tweet-prompts-fix-to-awspowershell-module-2016.

I get that a tweet probably isn’t the preferred method of reporting problems, but it worked before, so why shouldn’t it again? That said, if there is a preferred method, then I’d be happy to use that, although it doesn’t make for as good a story.

So, here’s where we need a fix. The Stop-EC2Instance cmdlet includes a -Terminate switch parameter that indicates it will terminate the instance (think, remove) in addition to stopping it. It works; it really does terminate the instance. The problem here is that the help file indicates it will prompt the user for confirmation unless the -Force parameter is also included. Nope; it doesn’t prompt. Not for me at least. It does terminate the instance, however, and it does so with no questions asked. It didn’t get me, but it might ruin someone’s day someday.

I didn’t try it, but it seems that there’s some built-in protection, although it’s not the default.


So you can see it yourself, here’s two PowerShell commands I ran against two different EC2 instances. In the first command I simply stop an EC2 instance. In the second, I added the -Terminate switch. As I mentioned, it works, but there wasn’t a confirmation prompt. This was tested on AWS Tools for Windows PowerShell and the newest version as of this writing,



My suggestion to resolve this problem is to remove the -Terminate switch from the Stop-EC2Instance cmdlet, and make a Remove-EC2Instance cmdlet. Maybe alias it with Terminate-EC2Instance, as Terminate isn’t an approved verb. In fact, when I first wanted to remove an EC2 instance, I started by hunting for a Remove-EC2Instance cmdlet. Tracking down the -Terminate switch of Stop-EC2Instance was the last place I would’ve looked. It seems to go against all PowerShell conventions. Does Stop-Transcript have an option to remove a transcript as part of its usage? Does Stop-VM in Hyper-V delete the VM? Does Stop-Cluster include a way to delete the cluster. No. Terminating an instance shouldn’t be a part of stopping an instance unless Stop-EC2Instance can be piped to Remove-EC2Instance. Think about the safety that a separate cmdlet would provide (and it’s not like the AWS Tools team is shy about adding new cmdlets).

There’s a couple cmdlets out there that can be used to get the metadata from a compiled PowerShell cmdlet. We use it as a part of writing proxy functions. By using this, I was able to determine the reason why it doesn’t prompt. The problem, as best I can tell, is that Stop-EC2Instance’s ConfirmImpact CmdletBinding argument is set to Medium and the default value of the $ConfirmPreference variable is set to High.


This means that no matter how the Stop-EC2Instance cmdlet is run, it’s never going to prompt for confirmation to terminate, unless someone has modified their $ConfirmPreference value to Medium, and that’s not likely at all. Since a cmdlet, or advanced function, can’t have more than one ConfirmImpact argument, we need the terminate functionality removed from Stop-EC2Instance and the development of a Remove-EC2Instance cmdlet. For comparison, here’s the CmdletBinding attribute for the Remove-ADGroupMembership Active Directory cmdlet. This one always prompts unless we include -Confirm:$false.


I get this fix is much more involved than the last one I brought up (changing the name of a parameter), and would require more work. Additionally, it’s probably one of those things that have to be discussed among the AWS Tools team members and management. Before I close, I should make sure everyone knows that AWS is still new to me, and as such, there may be things that weren’t considered, or known, when this post was written.

Thanks for reading, and enjoy the upcoming weekend.