Conditional loading of snapins in profile - powershell

We have an internal application that utilizes PowerShell. In my profile (Microsoft.PowerShell_profile.ps1) I have added references to various snap-ins that we've created:
#
# Profile for Joe Blow
#
Add-PSSnapIn CompanySnapin
Add-PSSnapin PowerShellTestTools
Add-PSSnapin SqlServerCmdletSnaps -ErrorAction SilentlyContinue
The problem I'm having is that when I start this internal application, the above lines of code, throw errors.
My question is, is there a way (in my profile script) where I can test WHO or WHAT is trying to open the profile and do things accordingly ?
Example might be:
if (!internalApplication)
{
Add-PSSnapIn CompanySnapin
Add-PSSnapin PowerShellTestTools
Add-PSSnapin SqlServerCmdletSnaps -ErrorAction SilentlyContinue
}
so I get the snapins if I launch the PowerShell command line utility. Otherwise, nothing is "added".
Thanks !

It depends on custom app/ host implementation, really. It also means there are at least few ways to skin the cat.
You can start with checking if $Host.Name differs.
Next - check if certain properties are present/ set (like $Host.UI.RawUI.BackgroundColor).
Once you know the difference - you just need to put any code that causes issues in if {} else {} and you should be good to go.

Related

Faulty PowerShell cmdlets filling up $Error automatic variable

In order to be informed when PowerShell Startup / Logon scripts running on remote computers have bugs, I tend to end scripts with the following:
If ($Error) {
(Code that sends a notification email to system administrators attaching the contents of the $Error variable for troubleshooting)
}
This is a great 'tell tale' to pick up edge cases / bugs. However, I've found some basic built-in PowerShell cmdlets dump data into $Error even on successful runs - for example, try:
$Error.Clear()
Get-NetIPConfiguration
$Error
And you'll see a load of errors in $Error that are not shown during normal output but look like:
Get-NetRoute : No matching MSFT_NetRoute objects found by CIM query for instances of the ROOT/StandardCimv2/MSFT_NetRoute class on the CIM server: SELECT * FROM
MSFT_NetRoute WHERE ((DestinationPrefix LIKE '0.0.0.0/0')) AND ((InterfaceAlias LIKE 'OpenVPN Wintun')). Verify query parameters and retry.
Get-NetConnectionProfile : No MSFT_NetConnectionProfile objects found with property 'InterfaceAlias' equal to 'Local Area Connection'. Verify the value of the property and
retry.
or
$Error.Clear()
Get-NetIPAddress
$Error
will return:
“Infinite : The term '“Infinite' is not recognized as the name of a cmdlet, function, script file, or operable program. Check the spelling of the name, or if a path was
included, verify that the path is correct and try again.
(A nice little bug for Microsoft to solve at some point, doubtless!)
Since it's unlikely that the cmdlets will be fixed any time soon, is there a way to run these cmdlets without them clogging up $Error with their useless information?
This is not a duplicate of Powershell: How can I stop errors from being displayed in a script? since that covers errors that actually display in red on the PowerShell console during a 'failed' run of the cmdlet; this is about errors generated by some cmdlets in the background during an apparently 'successful' run of a cmdlet which for some reason only get written to the automatic $Error variable.
Nonetheless I have already tried a number of solutions suggested in that post:
Running the cmdlets with -ErrorAction Ignore
Running the cmdlets with -ErrorAction SilentlyContinue
Running the cmdlets inside try {} catch {}
Running the cmdlets inside try {} catch {} with -ErrorAction Stop
Running the cmdlets with 2>$null following them
Setting $ErrorActionPreference = "SilentlyContinue" before running the cmdlets
I may be asking the impossible, but the way these cmdlets behave does make $Error very hard to use as an actual log, just want to know if I'm missing a trick.
I would like to be able to encapsulate buggy cmdlets in such a way that 'hidden' errors do not go into the automatic $Error variable.
I agree with #zett42' comment: I think you can't really prevent cmdlets from adding to $Error.
Also knowing that these "phantom errors" might already occur with a simple (Try/Catch) statement like:
Try { 1/0 } Catch {}
Anyways, you might consider to mark the last one and remove the errors added after that/ Like:
$HashCode = if ($Error) { $Error[0].GetHashCode() }
Get-NetIPAddress
While($Error -and $Error[0].GetHashCode() -ne $HashCode) { $Error.RemoveAt(0) }
Use the common -ErrorVariable parameter in order to collect only the (non-terminating) errors directly emitted or intentionally passed through by a cmdlet (those that it internally silences or ignores will not be captured):
# $errs is a self-chosen variable; note that it must be specified WITHOUT $
Get-NetIPAddress -ErrorVariable errs
# $errs now contains any (non-terminating) errors emitted by the
# Get-NetIPAddress call, as a [System.Collections.ArrayList] instance.
# (If no errors occurred, the list is empty).
Note: To also silence errors, combine -ErrorVariable errs with -ErrorAction SilentlyContinue (-ErrorAction SilentlyContinue does not work - see below).
The automatic $Error variable is designed to provide a session-wide log of all errors.
However, (script) cmdlets that deliberately ignore errors can avoid logging unnecessary errors by using -ErrorAction Ignore in internal calls - assuming that the errors are not only to be silenced, but also needn't be inspected.
(If errors need to be inspected after having collected them with -ErrorVariable, use of -ErrorAction Ignore is not an option, because it prevents error collection.)
The CDXML-based cmdlets from the NetTCPIP module, such as Get-NetIPAddress unfortunately use -ErrorAction SilentlyContinue in cases where -ErrorAction Ignore would suffice.
Conceivably, the cmdlet-generation code predates v3 of PowerShell, when the Ignore value was introduced.

PowerShell - ActiveDirectory Module

I need the ability to have users run a script that requires the ActiveDirectory module. I copied over the following:
"C:\Windows\System32\WindowsPowerShell\v1.0\Modules\ActiveDirectory", "Microsoft.ActiveDirectory.Management.resources.dll", "Microsoft.ActiveDirectory.Management.dll".
The script runs two Get-ADUser commands, 1 without the -Server parameter and the other with. The issue is that the former is working but the latter is not.
Is there another module that I need to copy over?
I don't like the idea of installing administrative tools for non-admins. Even if you could get away with copying files and not doing the full-blown RSAT installation. Not the least of reasons is you are dramatically increasing the attack surface for malicious actors. The better solution is (Just Enough Administration) JEA, or a philosophically similar approach.
JEA / Contrained endpoints can get complicated, but a summary of what you can do looks something like this:
New-PSSessionConfigurationFile -Path 'C:\PSSessionConfigs\DemoPSEndpointConfig.pssc' -ModulesToImport ActiveDirectory -VisibleCmdlets "Get-ADUser"
Register-PSSessionConfiguration -Path 'C:\PSSessionConfigs\DemoPSEndpointConfig.pssc' -ShowSecurityDescriptorUI -Name DemoPSEndPoint
Run these commands on a system that has the ActiveDirectory module (likely the whole RSAT component) installed, it doesn't need to be a Domain Controller. It will create a new PowerShell remoting endpoint configuration that exposes only the commands you wish. The Register-PSSessionConfiguration command will display a security dialog where you can permission which users you want to allow to connect, you want to grant them read & execute permission. Once that's done, you can get the results with an Invoke-Command command like this:
Invoke-Command -ComputerName <ServerName> -ConfigurationName DemoPSEndPoint -ScriptBlock { Get-ADUser <UserName> }
You can add the -Server parameter in the command without issue. You can expand the cmdlets you are allowing in the New-PSSessionConfiguration command.
Again this is very much a summary of a more complex topic but should be enough to get what you want.
Personally, I don't use configuration files as much as I use startup scripts. I think the latter is more flexible. You can get some information about that here. If you really want to dig into this there are references at the end of the article including a link to the PowerShell JEA documentation. There's also a link to some of the MVP articles I used to develop my own endpoints.
The ActiveDirectory module is dependent on the RSAT (remote server administration tool). This is avalible to install/activate through powershell: https://mikefrobbins.com/2018/10/03/use-powershell-to-install-the-remote-server-administration-tools-rsat-on-windows-10-version-1809/
With this installed you automatically also get the Activedirectory module installed.

PowerShell ignoring Write-Verbose while running Import-Module

For presenting the problem, I have this simple script saved as PowerShell module (test.psm1)
Write-Verbose 'Verbose message'
In real life, it includes command to import additional functions, but that is irrelevant at the moment.
If I run Import-Module .\test.psm1 -Verbose -Force I get only
VERBOSE: Loading module from path 'C:\tmp\test.psm1'.
My Write-Verbose is ignored 😟
I tried adding cmdletbinging but it also did not work.
[cmdletbinding()]
param()
Write-Verbose 'Verbose message'
Any clue how to provide Verbose output while importing the PowerShell module?
P.S. I do not want to display Verbose information always, but only if -Verbose is specified. Here would be my expected output for these two different cases:
PS C:\> Import-Module .\test.psm1 -Verbose -Force # with verbose output
VERBOSE: Loading module from path 'C:\tmp\test.psm1'.
VERBOSE: Verbose message
PS C:\> Import-Module .\test.psm1 -Force # without verbose output
PS C:\>
That is an interesting situation. I have a theory, but if anyone can prove me wrong, I would be more than happy.
The short answer: you probably cannot do what you want by playing with -Verbose only. There may be some workarounds, but the shortest path could be setting $VerbosePreference.
First of all, we need to understand the lifetime of a module when it is imported:
When a module is imported, a new session state is created for the
module, and a System.Management.Automation.PSModuleInfo object is
created in memory. A session-state is created for each module that is
imported (this includes the root module and any nested modules). The
members that are exported from the root module, including any members
that were exported to the root module by any nested modules, are then
imported into the caller's session state. [..] To send output to the host, users should run the Write-Host cmdlet.
The last line is the first hint that pointed me to a solution: when a module is imported, a new session state is created, but only exported elements are attached to the global session state. This means that test.psm1 code is executed in a session different than the one where you run Import-Module, therefore the -Verbose option, related to that single command, is not propagated.
Instead, and this is an assumption of mine, since I did not find it on the documentation, configurations from the global session state are visible to all the child sessions. Why is this important? Because there are two ways to turn on verbosity:
-Verbose option, not working in this case because it is local to the command
$VerbosePreference, that sets the verbosity for the entire session using a preference variable.
I tried the second approached and it worked, despite not being so elegant.
$VerbosePreference = "Continue" # print all the verbose messages, disabled by default
Import-Module .\test.psm1 -Force
$VerbosePreference = "SilentlyContinue" # restore default value
Now some considerations:
Specifying -Verbose on the Import-Module command is redundant
You can still override the verbosity configuration inside your module script, by using
Write-Verbose -Message "Verbose message" -Verbose:$false
As #Vesper pointed out, $false will always suppress the Write-Verbose output. Instead, you may want to parameterized that option with a boolean variable assigned in a previous check, perhaps. Something like:
if (...)
{
$forceVerbose=$true
}
else
{
$forceVerbose=$false
}
Write-Verbose -Message "Verbose message" -Verbose:$forceVerbose
There might be other less invasive workarounds (for instance centered on Write-Host), or even a real solution. As I said, it is just a theory.
Marco Luzzara's answer is spot on (and deserves the bounty in my opinion) in regards to the module being run in its own session state, and that by design you can't access those variables.
An alternative solution to setting $VerbosePreference and restoring it, is to have your module take a parameter specifically for this purpose. You touched on this a little bit by trying to add [CmdletBinding()] to your module; the problem is you have no way to pass in named parameters, only unnamed arguments, via Import-Module -ArgumentList, so you can't specifically pass in a $true for -Verbose.
Instead you can specify your own parameter and use it.
(psm1)
[CmdletBinding()]param([bool]$myverbose)
Write-Verbose "Message" -Verbose:$myverbose
followed with:
Import-Module test.psm1 -Force -ArgumentList $true
In the above example, it would apply only to a specific command, where you were setting -Verbose:$myverbose every time.
But you could apply it to the module's $VerbosePreference:
[CmdletBinding()]param([bool]$myverbose)
$VerbosePreference = if ($myverbose) { 'Continue' } else { 'SilentlyContinue' }
Write-Verbose "Message"
That way it applies throughout.
At this point I should mention the drawback of what I'm showing: you might notice I didn't include -Verbose in the Import-Module call, and that's because, it doesn't change the behavior inside the module. The verbose messages from inside will be shown purely based on the argument you passed in, regardless of the -Verbose setting on Import-Module.
An all-in-one solution then goes back to Marco's answer: manipulating $VerbosePreference on the caller's side. I think it's the only way to get both behaviors aligned, but only if you don't use -Verbose switch on Import-Module to override.
On the other hand, within a scope, like within an advanced function that can take -Verbose, setting the switch changes the local value of $VerbosePreference. That can lead us to wrap Import-Module in our own function:
function Import-ModuleVerbosely {
[CmdletBinding()]
param($Name, [Switch]$Force)
Import-Module $Name -Force:$Force
}
Great! Now we can call Import-ModuleVerbosely test.psm1 -Force -Verbose. But... it didn't work. Import-Module did recognize the verbose setting but it didn't make it down into the module this time.
Although I haven't been able to find a way to see it, I suspect it's because the variable is set to Private (even though Get-Variable seems to say otherwise) and so that value doesn't make it this time. Whatever the reason.. we could go back to making our module accept a value. This time let's make it the same type for ease of use:
(psm1)
[CmdletBinding()]param([System.Management.Automation.ActionPreference]$myverbose)
if ($myverbose) { $VerbosePreference = $myverbose }
Write-Verbose "message"
Then let's change the function:
function Import-ModuleVerbosely {
[CmdletBinding()]
param($Name, [Switch]$Force)
Import-Module $Name -Force:$Force -ArgumentList $VerbosePreference
}
Hey now we're getting somewhere! But.. it's kind of clunky isn't it?
You could go farther with it, making a full on proxy function for Import-Module, then making an alias to it called Import-Module to replace the real one.
Ultimately you're trying to do something not really supported, so it depends how far you want to go.

Remove Class from Memory in PowerShell

I've created a class called "Application" and loaded it in my main script with:
Import-Module -NAME "C:\PowerShell_Scripts\Class\Application.ps1" -GLOBAL -FORCE;
However if I ONLY make changes to the class file and run the code in PowerShell ISE none of the changes are applied. It's almost as if the class is still in memory even though I've used -FORCE.
I've also tried to remove the module before loading it and the same issue happens:
Remove-Module "Application" -ErrorAction Ignore -FORCE;
Import-Module -NAME "C:\PowerShell_Scripts\Class\Application.ps1" -GLOBAL -FORCE;
If I make a single character change in my main script then it reloads the class! But I shouldn't have to modify the main script to force PowerShell to reload the class, that just seems silly.
Is there a way to remove the Application class from memory if it exists?
NOTE: Files with just functions in them work file. This only applies to Class imports.
Addition: In the console, if I run the Remove-Module command it runs successfully but I can STILL create new objects with:
$appDetails = [Application]::new($applicationID);
Doesn't make sense to me...
MAIN SCRIPT:
# Application Details
# -----------------
#ID
$applicationID = 1;
############################################
#
# Load Supporting Scripts
#
############################################
try
{
Remove-Module "Application" -ErrorAction Ignore -FORCE;
Remove-Module "Common" -ErrorAction Ignore -FORCE;
Remove-Module "ServerData" -ErrorAction Ignore -FORCE;
Import-Module -NAME "C:\PowerShell_Scripts\Common.ps1" -GLOBAL -FORCE;
Import-Module -NAME "C:\PowerShell_Scripts\ServerData.ps1" -GLOBAL -FORCE;
Import-Module -NAME "C:\PowerShell_Scripts\Class\Application.ps1" -GLOBAL -FORCE;
}
catch
{
Write-Host "`nError: Cannot load required PowerShell scripts. Ensure C:\PowerShell_Scripts\ exists and has the required files." -ForegroundColor Red;
EXIT;
}
############################################
#
# Load the SharePoint Snapin Module.
#
############################################
LoadSharePointModule;
############################################
#
# Display component details to user.
#
############################################
#Create object of "Application" to get app details based on the ID.
$appDetails = [Application]::new($applicationID);
Write-Host "Ending ......";
APPLICATION CLASS FILE
Class Application
{
#Class Properties
[STRING] $appName;
[INT32] $appID;
[INT32] $versionMajor;
[INT32] $versionOS;
[INT32] $versionCentraAdmin;
[INT32] $versionMain;
[INT32] $versionGUI;
[INT32] $versionWorkflow;
[INT32] $versionForm;
[INT32] $versionVS;
[INT32] $versionOther;
[INT32] $versionFull;
[OBJECT] $spDevSite;
[OBJECT] $versionList;
#Constructor: Setup class properties.
Application ([INT32] $appID)
{
Write-Host "`nGathering application details ..." -ForegroundColor Yellow;
try
{
#Get the SharePoint Developer site Object.
$this.spDevSite = Get-SPWeb -ErrorAction Stop $GLOBAL:spDevURL;
}
catch
{
Write-Host "`nUnable to connect to SharePoint Developer site!: $($GLOBAL:spDevURL)";
#EXIT;
}
#Assign class property.
$this.appID = $appID;
}
}
I have deliberately set the URL for $GLOBAL:spDevURL; so that the Constructor fails for this test. It fails normally and displays
Write-Host "`nUnable to connect to SharePoint Developer site!: $($GLOBAL:spDevURL)";
But if I make a change to this line and run the script, the change is not applied.
The Known Issue
There is a known issue in PowerShell 5.0 and 5.1 that explains this behavior. The issue was acknowledged by DongBo Wang on the PowerShell 6 team in November 2016. He wrote the following:
"The module analysis result is stored in a cache with the module file path as the key and the PSModuleInfo object as the value. The cache entries are not properly invalidated based on the LastWriteTime of the module file, and thus same cached value got reused."
In other words, PowerShell 5.0, 5.1, and 6.0 keeps (and uses) old copies of classes in memory when it shouldn't.
Implications
This issue causes considerable problems for development using PowerShell classes if you do not compensate for it. I wrote a test that covers about 100 of the scenarios where class reloading is important. Vaguely speaking, in about 17 of those scenarios PowerShell 5.0 and 5.1 doesn't reload the class when it should. This means using the same session across edits creates a real likelihood the interpreter will have cached duplicate copies of the same or similar classes. That makes behavior unpredictable and causes strange results that cannot be troubleshot.
Workaround
I have found that you can still be productive developing using PowerShell classes. You just need to perform each test run in a fresh PowerShell session when a project involves PowerShell classes whose source the PowerShell interpreter may consider to have changed. The customary way to do this is to invoke your test command from your PowerShell console by invoking powershell.exe:
powershell.exe -Command { Invoke-Pester }
That's not a terribly inefficient test-edit-test cycle if you've got tight unit tests. If you need to step through code, you'll need to launch a fresh copy of ISE each time you make an edit.
With this workaround, I have found the productivity impact of this bug to be manageable. I developed this and this entirely using this workaround. Each of those projects involve a significant amount of code involving PowerShell classes.

Merge-SPLogFile- Doesn't return me any records

thanks for taking the time to try any help me out!
As the title suggests I cannot get the Merge-SPLogFile cmdlet to return me any results!
I find hunting down error messages in SharePoint logs a very time consuming and laborious process- Being relatively new to PowerShell I only recently stumbled across the cmdlet. Knowing how much time this could save me I was excited to implement it.
I started with the following code:
Add-PSSnapin Microsoft.SharePoint.Powershell
$correlationId = "C826869C-4A8E-10E2-6C5E-58A1C87EB651"
Merge-SPLogFile –Path “C:\Users\Administrator\Desktop\SPLog.log” –Correlation $correlationId -Overwrite
This gives me the warning- "WARNING: Cmdlet did not return any records in the log file. Check your time range or filters."
Naturally I typed the error into my search engine and it seems other people have had the same problems when the -Correlation argument isn't in upper case. I tried both uppercase and lowercase but to no avail. I was able to manually find the GUID in the logs so I know it exists.
When I ran out of luck with this technique I thought I would try filtering using different arguments (by time):
Add-PSSnapin Microsoft.SharePoint.Powershell
[int] $HowFarBack = 15
[int] $howFarBackInMinutes = (-1) * $HowFarBack
[datetime] $startDateTime = [System.DateTime]::Now.AddMinutes($howFarBackInMinutes)
write-host $startDateTime
Merge-SPLogFile -Path 'C:\Users\Administrator\Desktop\SPLog.log' -Overwrite -StartTime $startDateTime
I get exactly the same error. To rule out my arguments being incorrect I tried not giving it a filter at all:
Add-PSSnapin Microsoft.SharePoint.Powershell
Merge-SPLogFile -Path 'C:\Users\Administrator\Desktop\SPLog.log' -Overwrite
I still get- "WARNING: Cmdlet did not return any records in the log file. Check your time range or filters." The logs are all there and in the default "LOG" folder within the 15 hive. I haven't changed any logging settings away from the defaults.
I am running on SharePoint 2013 Foundation.
What am I doing wrong?
The problem in my case was that there was no diagnostic logging activated for my SharePoint Farm.
How to enable diagnostic logging
Go to your Central Administration (usually http://YOUR_SHAREPOINT:10000/) (there is also a shortcut in your start menu on the server you installed the SharePoint at)
Go to "Monitoring"
Under "Reporting" click "Configure diagnostic logging"
Select the categories that you want to merge in case of an Error. I just selected All Categories here. Then click the "Ok" button at the bottom of the page.
(5. Reproduce the error and use the SP Shell again to Merge the Log Files)