Querying a Service state from WMi

Reply

Remco Veenendaal Posted: 08-30-2011 4:26 AM

rated by 0 users

Hi,

I want to use powershell to query all of our servers from a input file to check the state of the SNMP service.

There can be two states stopped or running, if the state is stopped I want to start the SNMP service.

All the checks need to be logged to a log file.

Can you help me with this and also explain.

Thanks in advance.

Remco

Reply

RSiddaway replied on 08-30-2011 1:08 PM

rated by 0 users

Hi

This should do what you want

 function test-service{            
[CmdletBinding(SupportsShouldProcess=$true)]            
param (            
[parameter(Position=0,           
   ValueFromPipeline=$true,            
   ValueFromPipelineByPropertyName=$true)]           
   [Alias("CN", "ComputerName")]             
   [string]$computer="." ,

[string]$service="BITS" ,           
              
[parameter(Mandatory=$true)]           
   [string]$file           
              
)            
BEGIN {           
if (!(Test-Path -Path $file)){Throw "log file not found"}           
}           
PROCESS {           
$result =  Get-WmiObject -Class Win32_Service -ComputerName $computer -Filter "Name='$service'"           
           
Write-Verbose "$($result.State)"           
           
if ($($result.State) -eq "Running"){           
  $logdata = "{0,14} {1} {2}" -f $computer, $($result.State), (get-date -Format f )           
}           
else{            
$start = $result.StartService()            
if ($start.ReturnValue -eq 0){           
   $logdata = "{0,14} {1} {2}" -f $computer, "Service Started", (get-date -Format f )           
}           
else {           
  $logdata = "{0,14} {1} {2}" -f $computer, "Service FAILED to Start", (get-date -Format f )           
}             
}           
Add-Content -Path $file -Value $logdata            
}           
} ## end function

use it like this

Import-Csv computers.csv | test-service -service BITS -file log.txt

the CSV file has a single field called Computer

Need to define the log file AND it needs to exist - create an empty file with notepad

The file path  is tested. The call is made to Win32_service and the service started if it isn't running.

Data is added to the log file.

A couple of ideas to improve this:

• use the event log instead of a log file
• output objects into a CSV file

Reply

Remco Veenendaal replied on 08-31-2011 4:21 AM

rated by 0 users

Hi,

I took the following steps to get the script to work.

1. I created a CSV file, with collumn Computer with in each row under the collumn a server name. Currently two servers are added, one server with the SNMP service stopped and one server with the service enabled.

2. Created a logfile.

3. Added path to log file to function. $file = path to log file

When i run the script with the following command:

Import-Csv computers.csv | test-service -service SNMP -file log.txt

The following is shown in the log, the script just keeps running.

@{computers=OMS1001} Service FAILED to Start woensdag 31 augustus 2011 9:38
@{computers=RMS1001} Service FAILED to Start woensdag 31 augustus 2011 9:38
 @{computers=} Service FAILED to Start woensdag 31 augustus 2011 9:38
 @{computers=} Service FAILED to Start woensdag 31 augustus 2011 9:38
 @{computers=} Service FAILED to Start woensdag 31 augustus 2011 9:38
 @{computers=} Service FAILED to Start woensdag 31 augustus 2011 9:38
 @{computers=} Service FAILED to Start woensdag 31 augustus 2011 9:38
 @{computers=} Service FAILED to Start woensdag 31 augustus 2011 9:38
 @{computers=} Service FAILED to Start woensdag 31 augustus 2011 9:38
 @{computers=} Service FAILED to Start woensdag 31 augustus 2011 9:38

The following is shown, when function is called with -Whatif

What if: Performing operation "Add Content" on Target "Path: D:\scripts\SNMP\log.txt".
Get-WmiObject : De RPC-server is niet beschikbaar. (Uitzondering van HRESULT: 0x800706BA)
At line:19 char:25
+ $result =  Get-WmiObject <<<<  -Class Win32_Service -ComputerName $computer -Filter "Name='$service'"           
    + CategoryInfo          : InvalidOperation: (:) [Get-WmiObject], COMException
    + FullyQualifiedErrorId : GetWMICOMException,Microsoft.PowerShell.Commands.GetWmiObjectCommand
 
You cannot call a method on a null-valued expression.
At line:27 char:30
+ $start = $result.StartService <<<< ()            
    + CategoryInfo          : InvalidOperation: (StartService:String) [], RuntimeException
    + FullyQualifiedErrorId : InvokeMethodOnNull

Two questions:

1. The script keeps running as seen in the log file, it runs against no computer. HOw come?

2. The check and start commands are not functioning, I run the script as Domain admin?

Reply

Remco Veenendaal replied on 08-31-2011 4:30 AM

rated by 0 users

When I run the following command in PS ISE, it works well

result =  Get-WmiObject -Class Win32_Service -ComputerName Servername -Filter "Name='SNMP'"  

Reply

RSiddaway replied on 08-31-2011 1:13 PM

rated by 0 users

Check that the computers listed in your csv file actually exist