Nagios Conference 2011 - Michael Medin - Workshop: Scripting On The Windows Side

Scripting...
…on the Windows side

These slides represent the work and opinions of the author and do not constitute official positions of any organization sponsoring the author’s work
This material has not been peer reviewed and is presented here as-is with the permission of the author.
The author assumes no liability for any content or opinion expressed in this presentation and or use of content herein.
Disclaimer!
It is not their fault!
It is not my fault!
It is your fault!

External Scripts
Internal Scripts
Arguments
Scripting: Batch files
Wrapped scripts
Scripting: VBA
Internal Scripts
Agenda

Windows monitoring
NSClient++ (from a scripters perspecitve)

External Scripts
The normal kind of scripts
Can be written in:
Batch
VBA/VBScript (pretty popular on Windows)
Powershell (a rather strange language)
But also:
Perl, python, bash, etc etc…
Internal Scripts
Can interact with (other) internal commands
Can access settings
Can hold state
Can be written in:
Lua
Python (requires python on the machine)
Two kinds of scripts

Enable the check module
[/modules]
CheckExternalScripts= # Runs the script
NRPEServer= # NRPE server
Each script requires a definition
[/settings/External Scripts]
check_es_test=scriptstest.bat
Options disabled by default (for a reason)
allow arguments = false
allow nasty characters = false
Configuring External Scripts

Enable the check module
[/modules]
LUAScript=
PythonScript=
Each script requires a definition
[/settings/LUA/Scripts]
<alias>=test.lua
[/settings/python/Scripts]
<alias>=test.py
Scripts requires NRPE/NSCA (or NSCP)
[/modules]
NRPEServer=
Configuring Internal Scripts

Can be configured in many places
Is probably more confusing then it is worth
The server module
Means NO commands can have arguments
The script module
Means NO external script can have arguments
Allow arguments

Allow arguments

Writing our first Scripts
The first batch script

Output:
Use: echo <text>
Don’t forget @echo off (or all commands will be echoed)
Exit statuses:
Use: exit <code>
0 = OK
1 = Warning
2 = Critical
3 = Unknown
NSC.ini syntax:
[/settings/External Scripts/scripts]
my_script=scriptsscript.bat
Reference:
http://www.ss64.com/nt/
Don’t let preconceptions fool you: batch can actually do a lot!
Writing a Script (Batch)

@echo off
echo CRITICAL: Everything is not going to be fine
exit 2
A basic script (batch)

…NSClient++scripts>cmd /ctest.bat
CRITICAL: Everything is not going to be fine
…NSClient++scripts>echo %ERRORLEVEL%
2
Running from Command Line

D:demo>nscp --test
NSClient++ 0,4,0,98 2011-09-06 x64 booting...
Boot.ini found in: D:/demo//boot.ini
Boot order: ini://${shared-path}/nsclient.ini, old://${exe-path}/nsc.ini
Activating: ini://${shared-path}/nsclient.ini
Creating instance for: ini://${shared-path}:80/nsclient.ini
Reading INI settings from: D:/demo//nsclient.ini
Loading: D:/demo//nsclient.ini from ini://${shared-path}/nsclient.ini
Booted settings subsystem...
On crash: restart: NSClientpp
Archiving crash dumps in: D:/demo//crash-dumps
booting::loading plugins
Found: CheckExternalScripts as
Processing plugin: CheckExternalScripts.dll as
addPlugin(D:/demo//modules/CheckExternalScripts.dll as )
Loading plugin: Check External Scripts as
NSClient++ - 0,4,0,98 2011-09-06 Started!
Enter command to inject or exit to terminate...
Running from NSClient

Enter command to inject or exit to terminate...
my_scripts
Injecting: my_script...
Arguments:
Result my_script: WARNING
WARNING:Hello World
Running from NSClient
Command
Return Status
Return Message

Demo

Killing notepad once and or all!

TASKKILL [/S dator [/U användarnamn [/P lösenord]]]]
{ [/FI filter] [/PID process-ID | /IM avbildning] } [/T][/F]
Beskrivning:
Det här verktyget används för att avsluta en eller flera aktiviteter
utifrån process-ID (PID) eller avbildningsnamn.
Parameterlista:
…
/FI filter Använder ett filter för att välja aktiviteter.
Jokertecknet * kan användas, t.ex:
imagenameeq note*
/PID process-ID Anger process-ID för den process som ska avbrytas.
Använd kommandot Tasklist för att hämta process-ID
/IM avbildning Anger avbildning för den process som
för den process som ska avslutas. Jokertecknet *
användas för att ange alla aktiviteter eller
avbildningar.
Killing notepad once and for all!

@echo off
taskkill /im notepad.exe 1>NUL 2>NUL
IF ERRORLEVEL 128 GOTO err
IF ERRORLEVEL 0 GOTO ok
GOTO unknown
:unknown
echo UNKNOWN: unknown problem killing notepad...
exit /B 3
:err
echo CRITICAL: Notepad was not killed...
exit /B 1
:ok
echo OK: Notepad was killed!
exit /B 0
KILL!!!

Demo
Killing notepad…

Wrapped scripts
Interlude

NSC.ini syntax:
[External Scripts]
check_bat=scriptscheck_test.bat
Or
[Wrapped Scripts]
check_test=check_test.bat
Adding a Script (.bat)

NSC.ini syntax:
[External Scripts]
check_test=cscript.exe /T:30 /NoLogo scriptscheck_test.vbs
Or
[Wrapped Scripts]
check_test=check_test.vbs
Adding a Script (.VBS)

NSC.ini syntax:
[External Scripts]
check_test=cscript.exe /T:30 /NoLogo scriptslibwrapper.vbs scriptscheck_test.vbs
Or
[Wrapped Scripts]
check_test=check_test.vbs
Adding a Script (.VBS) w/ libs

NSC.ini syntax:
[External Scripts]
check_test=cmd /c echo scriptscheck_test.ps1; exit($lastexitcode) | powershell.exe -command -
Or
[Wrapped Scripts]
check_test=check_test.ps1
Adding a Script (.PS1)

[…/wrappings]
bat=scripts%SCRIPT% %ARGS%
vbs=cscript.exe //T:30 //NoLogo scriptslibwrapper.vbs %SCRIPT% %ARGS%
ps1=cmd /c echo scripts%SCRIPT% %ARGS%; exit($lastexitcode) | powershell.exe -command -
[…/wrapped scripts]
check_test_vbs=check_test.vbs /arg1:1 /variable:1
check_test_ps1=check_test.ps1 arg1 arg2
check_test_bat=check_test.bat $ARG1$ arg2
check_battery=check_battery.vbs
check_printer=check_printer.vbs
; So essentially it is a macro! (but a nice one)
What is wrapped scripts?

Writing your first Scripts
Writing a simple VB script

Output:
Use: Wscript.StdOut.WriteLine <text>
Exit statuses:
Use: Wscript.Quit(<code>)
0 = OK
1 = Warning
2 = Critical
3 = Unknown
NSC.ini syntax:
[External Scripts]
check_vbs=cscript.exe //T:30 //NoLogo scriptscheck_vbs.vbs
//T:30 Is the timeout and might need to be changed.
Reference:
http://msdn.microsoft.com/en-us/library/t0aew7h6(VS.85).aspx
Writing a Script (VBS)

wscript.echo ”Hello World"
wscript.quit(0)
Hello_World.vbs

Set <variable name>=CreateObject(“<COM Object>")
There is A LOT of objects you can create
A nice way to interact with other applications
For instance:
Set objWord = CreateObject("Word.Application")
objWord.Visible = True
Set objDoc = objWord.Documents.Add()
Set objSelection = objWord.Selection
objSelection.Font.Name = “Comic Sans MS"
objSelection.Font.Size = “28"
objSelection.TypeText“Hello World"
objSelection.TypeParagraph()
objSelection.Font.Size = "14"
objSelection.TypeText "" & Date()
objSelection.TypeParagraph()
Object oriented programming (ish)

Demo:
Words…

strFile=”c:windows”
Dim oFSO
Set oFSO=CreateObject("Scripting.FileSystemObject")
If oFSO.FileExists(strFile) Then
wscript.echo”Yaay!"
wscript.quit(0)
else
wscript.echo“Whhh… what the f***!"
wscript.quit(2)
end if
Are we running windows?

Demo:
Are we running Windows?

Using the library
Dissecting a VBScript

Can be used to extend NSClient++
Are very powerful
A good way to:
Alter things you do not like
Create advanced things
Are written in Lua or Python
Possibly unsafe
Runs inside NSClient++
Internal Scripts

Internal scripts are fundamentally different
One script is NOT equals to one function
A script (at startup) can:
Register query (commands) handlers
Register submission (passive checks) handlers
Register exec handlers
Register configuration
Access configuration
Handlers can:
Execute queries (commands)
Submit submissions (passive checks)
Etc etc…
Anatomy of an internal script

definit(plugin_id, plugin_alias, script_alias):
conf = Settings.get()
reg = Registry.get(plugin_id)
reg.simple_cmdline('help', get_help)
reg.simple_function(‘command', cmd, ‘A command…')
conf.set_int('hello', 'python', 42)
log(Answer: %d'%conf.get_int('hello','python',-1))
def shutdown():
log(“Shutting down…”)
A basic script

defget_help(arguments):
return (status.OK, ‘Im not helpful ')
def test(arguments):
core = Core.get()
count = len(arguments)
(retcode, retmessage, retperf) =
core.simple_query(‘CHECK_NSCP’, [])
return (status.OK, ‘Life is good… %d'%count)
A basic script

Questions?
Q&A

Michael Medin
michael@medin.name
http://www.linkedin.com/in/mickem
Information about NSClient++
http://nsclient.org
Facebook: facebook.com/nsclient
Slides, and examples
http://nsclient.org/nscp/conferances/2011/nwcna/
Thank You!

Nagios Conference 2011 - Michael Medin - Workshop: Scripting On The Windows Side

by Nagios

Accessibility

Categories

Upload Details

Usage Rights

1 Embed 62

Statistics

Nagios Conference 2011 - Michael Medin - Workshop: Scripting On The Windows Side Presentation Transcript