Skip to main content

PowerShell Code That Write’s it’s Own Code

I know, sounds a bit out there, but it is possible.

My PowerShell Class this week took a question from PowerShell.com. I do this every once and a while so we can apply our newly acquired skill sets to real life situations. This time around we helped out an IT Pro who was importing a CSV file to modify user objects using the Set-ADUser cmdlet of the Active Directory Module for Windows PowerShell.

The problem that he was having is that the database that generated this CSV file would occasionally place a NULL value in one of the properties. If you hard code Set-ADUser with a parameter, but then feed it a NULL value, it errors. The same thing happens if you pipe in a NULL value. He needed help trying to fix this. So, we went into action. And generated the cmdlet below.

The cool part about this code is that we did not hard code anything with regards to sending data to Set-ADUser. We utilized Invoke-Expression to execute commands that the code generates live. We also did not know if the CSV file contained data that would not be valid for a user object. We handled this little issue the same way that we handled the NULL values in the CSV file. We captured the errors and did nothing with them. No harm, no foul. We used SamAccountName as our identity property. Just modify the code to fit the identity property that you are using. You must have access to the Active Directory module for Windows PoweerShell for this to work.

 

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

19

20

21

22

23

24

25

26

27

28

29

30

31

32

33

34

35

36

37

38

39

40

41

42

43

44

45

46

47

48

49

50

51

52

53

54

55

56

57

58

59

60

61

62

63

64

65

66

67

68

69

70

71

72

73

74

75

76

77

78

79

80

81

82

83

84

85

86

87

88

89

90

91

92

93

94

95

96

97

98

99

100

101

102

103 

 

Function Set-ADUserFromCSV

{

[cmdletbinding()]

Param(

   

    [parameter(Mandatory=$true,

    ValueFromPipeline=$true)]

    $UserData,

 

    [Switch]

    $PassThru

)

Begin {} # END: Begin Block

Process

{

    # Import the data.

    $Data = Import-Csv -Path E:\data.csv

 

    # Extract the valid Property names from the object.

    $Props = $Data[0] | GM |

        Where-Object MemberType -eq NoteProperty |

        Select-Object -ExpandProperty Name

 

    $Data | ForEach-Object {

        ForEach ($P in $Props)

        {

            # This is the part that writes its own code.

            $String = "Set-ADUser -Identity $($_.SamAccountName) -$P $($_.$P)"

 

            # Add PassThru is requested.

            If ($PassThru) {$String += " -PassThru"}

 

            Try

            {

                # This makes the magic work.

                Write-Verbose "Executing: $String"

                Invoke-Expression -Command "$String" -ErrorAction Stop

            } # End: Try Block

            catch

            {

                <#

                Two items can cause errors here.

                1. Your CSV file have a property that is not a valid property for

                   a user object.

                2. You have a NULL field in your CSV.

                This will simply ignore the error and keep going.

                #>

 

            } # END: Catch Block

 

        } # END: ForEach ($P in $Props)

    } # END: ForEach-Object

} # END: Process Block

End {} #END: END: Block

<#

.SYNOPSIS

Modifies user accounts.

 

.DESCRIPTION

Takes an object containing SamAccountNames and other properties and

applies it to user accounts if the user account exists and the

property is a valid property for Set-ADUser.

 

.PARAMETER UserData

This is the object containing the data to be used to modify

the user object.

 

.PARAMETER PassThru

Places the modified user object into the pipeline.

 

.EXAMPLE

Import-Csv -Path E:\data.csv | Set-ADUserFromCSV

 

Modifies user objects based on the data imported from a CSV file.

 

.EXAMPLE

Import-Csv -Path E:\data.csv | Set-ADUserFromCSV -Verbose -PassThru

 

Modifies user objects based on the data imported from a CSV file.

This also places the user object into the pipeline and displays

verbose information.

 

.NOTES

Requires the Active Directory PowerShell Module.

 

===============================================================================

== Cmdlet: Set-ADUserFromCSV                                                 ==

== Author: Jason A. Yoder                                                    ==

== Company: MCTExpert of Arizona                                             ==

== Date:    2015JUN24                                                        ==

== Copyright: All rights reserved.                                           ==

== Version: 1.0.0.0                                                          ==

== Legal: The user assumes all responsibility and liability for the usage of ==

== this PowerShell code.  MCTExpert of Arizona, Its officers, shareholders,  ==

== owners, and their relatives are not liable for any damages.  As with all  ==

== code, review it and understand it prior to usage.  It is recommended that ==

== this code be fully tested and validated in a test environment prior to    ==

== usage in a production environment.                                        ==

==                                                                           ==

== Does this code make changes: Yes                                          ==

===============================================================================

#>

} # END: Function Set-ADUserFromCSV

 

 

 

 

Comments

Popular posts from this blog

Sticky Key problem between Windows Server 2012 and LogMeIn

This week I instructed my first class using Windows Server 2012 accessed via LogMeIn and discovered a Sticky Key problem every time you press the Shift key. Here is my solution to resolve this.  First off, in the Preferences of LogMeIn for the connection to the Windows Server, click General . Change the Keyboard and mouse priority to Host side user and click Apply at the bottom. On the Windows 2012 server, open the Control Panel – Ease of Access – Change how your keyboard works . Uncheck Turn on Sticky Keys . Click Set up Sticky Keys . Uncheck Turn on Sticky Keys when SHIFT is pressed five times . Click OK twice. If you are using Windows Server 2012 as a Hyper-V host, you will need to redo the Easy of Use settings on each guest operating system in order to avoid the Sticky Key Problem. Updated Information: March 20, 2013 If you continue to have problems, Uncheck Turn on Filter Keys .

Where did a User’s Account Get Locked Out?

Updated: May 15, 2015 When this article was originally published, two extra carriage returns were add causing the code to malfunction.  The code below is correct.   My client for this week’s PowerShell class had a really interesting question. They needed to know where an account is being locked out at. OK, interesting. Apparently users hop around clients and forget to log off, leading to eventual lock out of their accounts. The accounts can be unlocked, but are then relocked after Active Directory replication. This problem is solved in two parts. The first one is to modify the event auditing on the network. The second part is resolved with PowerShell. The first part involves creating a group policy that will encompass your Domain Controllers. In this GPO, make these changes. Expand Computer Configuration \ Policies \ Windows Settings \ Security Settings \ Advanced Audit Policy Configuration \ Audit Policies \ Account Management Double click User Account Management C...

Backup and Restore AD LDS with DSDBUTIL.exe

Active Directory Lightweight Directory Services allow you to create a directory service that allows applications to have access to user accounts, groups, and authentication similar to Active Directory Domain Services.  The big advantage here is that the schema of the directory service will not be bound by the rules of an Active Directory database.  Exchange 2007/2010, for example, use an instance of AD LDS on the Edge Transport Server to provide for user authentication from the internet.  Because your Active Directory database is not exposed to the internet, this is more secure. Applications will handle most of the dirty work should they require AD LDS.  You may want to make sure the database is being backed up and also have a restore plan in place.  Should the database become corrupt, the application that uses that database will fail.  This document will walk you through backing up and restoring an instance of AD LDS using the dsdbutil.exe command. Fi...