How to convert (and fixup) the RedHat RPM to run on Debian/Ubuntu

In an earlier post I had shown how I got the Xplat agent running on Ubuntu. I perfected the technique over time, and what follows is a step-by-step process on how to convert and change the RedHat package to run on Debian/Ubuntu. Of course this is still a hack… but some people asked me to detail it a bit more. At the same time, the cross platform team is working to update the the source code on codeplex with extra bits that will make more straightforward to grab it, modify it and re-compile it than it is today. Until then, here is how I got it to work.

I assume you have already copied the right .RPM package off the OpsMgr server’s /AgentManagement directory to the Linux box here. The examples below refer to the 32bit package, but of course the same identical technique would work for the 64bit version.

We start by converting the RPM package to DEB format:

root# alien -k scx-1.0.4-258.rhel.5.x86.rpm –scripts

scx_1.0.4-258_i386.deb generated

 

Then we need to create a folder where we will extract the content of the package, modify stuff, and repackage it:

root# mkdir scx_1.0.4-258_i386

root# cd scx_1.0.4-258_i386

root# ar -x ../scx_1.0.4-258_i386.deb

root# mkdir debian

root# cd debian

root# mkdir DEBIAN

root# cd DEBIAN

root# cd ../..

root# rm debian-binary

root# mv control.tar.gz debian/DEBIAN/

root# mv data.tar.gz debian/

root# cd debian

root# tar -xvzf data.tar.gz

root# rm data.tar.gz

root# cd DEBIAN/

root# tar -xvzf control.tar.gz

root# rm control.tar.gz

Now we have the “skeleton” of the package easily laid out on the filesystem and we are ready to modify the package and add/change stuff to and in it.

 

First, we need to add some stuff to it, which is expected to be found on a redhat distro, but is not present in debian. In particular:

1. You should copy the file “functions” (that you can get from a redhat/centos box under /etc/init.d) under the debian/etc/init.d folder in our package folder. This file is required/included by our startup scripts, so it needs to be deployed too.

Then we need to chang some of the packacge behavior by editing files under debian/DEBIAN:

2. edit the “control” file (a file describing what the package is, and does):

clip_image002

3. edit the “preinst” file (pre-installation instructions): we need to add instructions to copy the “issue” file onto “redhat-release” (as the SCX_OperatingSystem class will look into that file, and this is hard-coded in the binary, we need to let it find it):

clip_image004

these are the actual command lines to add for both packages (DEBIAN or UBUNTU):

# symbolic links for libaries called differently on Ubuntu and Debian vs. RedHat

ln -s /usr/lib/libcrypto.so.0.9.8 /usr/lib/libcrypto.so.6

ln -s /usr/lib/libssl.so.0.9.8 /usr/lib/libssl.so.6

the following bit would be Ubuntu-specific:

#we need this file for the OS provider relies on it, so we convert what we have in /etc/issue

#this is ok for Ubuntu (“Ubuntu 9.0.4 \n \l” becomes “Ubuntu 9.0.4”)

cat /etc/issue | awk ‘/\\n/ {print $1, $2}’ > /etc/redhat-release

while the following bit is Debian-specific:

#this is ok for Debian (“Debian GNU/Linux 5.0 \n \l” becomes “Debian GNU/Linux 5.0”)

cat /etc/issue | awk ‘/\\n/ {print $1, $2, $3}’ > /etc/redhat-release

 

4. Then we edit/modify the “postinst” file (post-installation instructions) as follows:

a. remove the 2nd and 3rd lines which look like the following

RPM_INSTALL_PREFIX=

export RPM_INSTALL_PREFIX

as they are only useful for the RPM system, not DEB/APT, so we don’t need them.

b. change the following 2 functions which contain RedHat-specific commands:

configure_pegasus_service() {

           /usr/lib/lsb/install_initd /etc/init.d/scx-cimd

}

start_pegasus_service() {

           service scx-cimd start

}

c. We need to change in the Debian equivalents for registering a service in INIT and starting it:

configure_pegasus_service() {

               update-rc.d scx-cimd defaults

}

start_pegasus_service() {

              /etc/init.d/scx-cimd start

}

5. Modify the “prerm” file (pre-removal instructions):

a. Just like “postinst”, remove the lines

RPM_INSTALL_PREFIX=

export RPM_INSTALL_PREFIX

b. Locate the two functions stopping and un-installing the service

stop_pegasus_service() {

         service scx-cimd stop

}

unregister_pegasus_service() {

          /usr/lib/lsb/remove_initd /etc/init.d/scx-cimd

}

c. Change those two functions with the Debian-equivalent command lines

stop_pegasus_service() {

           /etc/init.d/scx-cimd stop

}

unregister_pegasus_service() {

           update-rc.d -f scx-cimd remove

}

At this point the change we needed have been put in place, and we can re-build the DEB package.

Move yourself in the main folder of the application (the scx_1.0.4-258_i386 folder):

root# cd ../..

Create the package starting from the folders

root# dpkg-deb –build debian

dpkg-deb: building package `scx’ in `debian.deb’.

Rename the package (for Ubuntu)

root# mv debian.deb scx_1.0.4-258_Ubuntu_9_i386.deb

Rename the package (for Debian)

root# mv debian.deb scx_1.0.4-258_Debian_5_i386.deb

Install it

root# dpkg -i scx_1.0.4-258_Platform_Version_i386.deb

All done! It should install and work!

 

Next step would be creating a Management Pack to monitor Debian and Ubuntu. It is pretty similar to what Robert Hearn has described step by step for CentOS, but with some different replacements of strings, as you can imagine. I have done this but have not written down the procedure yet, so I will post another article on how to do this as soon as I manage to get it standardized and reliable. There is a bit more work involved for Ubuntu/Debian… as some of the daemons/services have different names, and certain files too… but nothing terribly difficult to change so you might want to try it already and have a go at it!

In the meantime, as a teaser, here’s my server’s (http://www.muscetta.com) performance, being monitored with this “hack”:

image

 

Disclaimer

The information in this weblog is provided "AS IS" with no warranties, and confers no rights. This weblog does not represent the thoughts, intentions, plans or strategies of my employer. It is solely my own personal opinion. All code samples are provided "AS IS" without warranty of any kind, either express or implied, including but not limited to the implied warranties of merchantability and/or fitness for a particular purpose.
THIS WORK IS NOT ENDORSED AND NOT EVEN CHECKED, AUTHORIZED, SCRUTINIZED NOR APPROVED BY MY EMPLOYER, AND IT ONLY REPRESENT SOMETHING WHICH I’VE DONE IN MY FREE TIME. NO GUARANTEE WHATSOEVER IS GIVEN ON THIS. THE AUTHOR SHALL NOT BE MADE RESPONSIBLE FOR ANY DAMAGE YOU MIGHT INCUR WHEN USING THIS INFORMATION. The solution presented here IS NOT SUPPORTED by Microsoft.

SCX Evolutions

During the beta of the Cross-Platform extensions and of System Center Operations Manager 2007 R2, the product team had promised to eventually release the SCX Providers’source code.

Now that this promise has been mantained, and the SCX providers have been released on Codeplex at http://xplatproviders.codeplex.com/ it should be finally possible to entirely build your own unsupported agent package, starting from source code, without having to modify the original package as I have shown earlier on this blog.
Of course this will still be unsupported by Microsoft Product support, but will eventually work just fine!
This is an extraordinary event in my opinion, as it is not a common event that Microsoft releases code as open source, especially when this is part of one of the product it sells. I suspect we will see more of this as we going forward.

Also, at R2 release time, some official documentation about buildilng Cross-Plaform Management Packs has been published on Technet.

Anyway, I have in the past posted a number of posts on my blog under this tag http://www.muscetta.com/tag/xplat/ (I will continue to use that tag going forward) which show/describe how I hacked/modified both the existing MPs AND the SCX agent package to let it run on unsupported distributions (and I think they are still useful as they show a number of techniques about how to test, understand and troubleshoot the Xplat agent a bit. In fact, I have first learned how to understand and modify the RedHat MPs to monitor CentOS and eventually even modified the RPM package to run on Ubuntu (which also works on Debian 5/Lenny), eventually, as you can see because I am now using it to monitor – from home, across the Internet – the machine running this blog:

www.muscetta.com Performance in OpsMgr

Or even, with or without OpsMgr 2007 R2, you could write your own scripts to interact with those providers, by using your favourite Scripting Language.

After all, those experimentations with Xplat got me a fame of being a “Unix expert at Microsoft” (this expression still makes me laugh), as I was tweeting here:
Unix expert at Microsoft

But really, I have never hidden my interest for interoperability and the fact that I have been using Linux quite a bit in the past, and still do.

Also, one more related information is that the fine people at Xandros have released their Bridgeways Management Packs and at the same time also started their own blog at http://blog.xplatxperts.com/ where they discuss some troubleshooting techniques for the Xplat agent, both similar to what I have been writing about here and also – of course – specific to their own providers, that are in their XSM namespace.

Disclaimer

The information in this weblog is provided “AS IS” with no warranties, and confers no rights. This weblog does not represent the thoughts, intentions, plans or strategies of my employer. It is solely my own personal opinion. All code samples are provided “AS IS” without warranty of any kind, either express or implied, including but not limited to the implied warranties of merchantability and/or fitness for a particular purpose.
THIS WORK IS NOT ENDORSED AND NOT EVEN CHECKED, AUTHORIZED, SCRUTINIZED NOR APPROVED BY MY EMPLOYER, AND IT ONLY REPRESENT SOMETHING WHICH I’VE DONE IN MY FREE TIME. NO GUARANTEE WHATSOEVER IS GIVEN ON THIS. THE AUTHOR SHALL NOT BE MADE RESPONSIBLE FOR ANY DAMAGE YOU MIGHT INCUR WHEN USING THIS INFORMATION. The solution presented here IS NOT SUPPORTED by Microsoft.

CentOS discovery in OpsMgr2007 R2 beta

Here we go again. Now that the OpsMgr2007 R2 beta is out, with an improved and revamped version of the System Center Cross Platform Extensions, I faced the issue of how to upgrade my test lab.

I have to say that OpsMgr2007 R2 beta release notes explain the known issues, and I had no trouble whatsoever upgrading the windows part. It just took its time (I am running virtual machines in my test lab, that don’t have the best performance), but it went smoothly and without a glitch. In a couple of hours I had everything upgraded: databases, RMS, reporting, agents, gateway. All right then. The new purple icons in System Center look cute, and the new UI has some great stuff, such as a long-awaited way to update your management packs directly from the Internet, better display of Overrides (kind of what we used to rely on Override Explorer for)… and  A LOT more new stuff that I won’t be wasting my Sunday writing about since everybody else has already done it two days ago:

opsmgr aggregated feed on Twitter

Therefore let’s get back to my upgrade, which is a lot more interesting (to me) than the marketing tam-tam 🙂

As part of the upgrade to R2, I had to first uninstall the Xplat beta refresh bits, which I had installed, including all Unix Management Packs. Including my CentOS Management Pack I had improvised.

So this is the new start page of the integrated Discovery Wizard:

Discovery Wizard

Looks nice and integrates the functionality of discovering and deploying Windows machines, SNMP Devices, and Unix/Linux machines.

Of course, my CentOS machine would not be discovered, and showed up as an unsupported platform. Of course my old Management Pack I had hacked together in XPlat Beta 1 did not work anymore. Therefore, I figured out I had to see what changes were there, and how to make it work again (of course it IS possible – It is NOT SUPPORTED, but I don’t care, as long as it works).

Since the existing agent could not be discovered, the first step I took was logging on the Linux box, un-install the old agent, and install the new one:

XPlat Agent RPM Install on CentOS

There I tried to discover again, but of course it still failed.

At that point I started taking a look at the new layout of things on the unix side. Most stuff is located in the same directories where beta1 was installed, and there are a bunch of useful commands under /opt/microsoft/scx/bin/tools.
You can check out the Open Pegasus version used:

[root@centos tools]# ./scxcimconfig –version
Version 2.7.0

Let’s take a look at what SCX classes we have available:

./scxcimcli nc -n root/scx -di |grep SCX | sort

./scxcimcli nc -n root/scx -di |grep SCX | sort

Nice. That’s the stuff we will be querying over WS-Man from the Management Server.

So let’s look at the OS Discovery, and we test it from the OpsMgr 2007 box:

winrm enumerate http://schemas.microsoft.com/wbem/wscim/1/cim-schema/2/SCX_OperatingSystem?__cimnamespace=root/scx -username:root -password:password -r:https://centos:1270/wsman -auth:basic -skipCACheck

it returns results:

OS WS-Man Query

At first I assumed this worked like in Beta1, therefore I exported RedHat management pack and I made my own version of it, replacing the strings it is expecting to find to discover CentOS instead than Redhat.

While the MP was syntactically correct and would import fine, the Discovery wizard still didn’t work.

I took one more look at the discoveries in the MP, and I found there are two more, targeted to Management Server, which is probably what gets used by the Discovery Wizard to understand what kind of agent kit needs to be deployed.

MP XML - Discoveries

So basically this discovery checks for the returned value from the module to determine if the discovered platform is a supported one:

Discovery Settings

But how does the module get its data?

Look at the layout of the /AgentManagement/UnixAgents folder on the Management Server:

/AgentManagement/unixAgents

That’s it: GetOSVersion.sh – a shell script. A nice, open, clear text, hackable shell script. Let’s take a look at it:

Discovery Script Hack

So that’s it, and how my modification looks like. What happens during the discovery wizard is that we probably copy the script over SCP to the box, execute it, look at a number of things, and return the discovery data we need.

If you do those steps manually, you see how the script returns something very similar to a PropertyBag, just like discoveries done by VBScript on Windows machines:

Discovery Script Output

So after modifying the script… here we go. The Wizard now thinks CentOS is Red Hat, and can install an agent on it:

Discovery Wizard

Deploying Agent

Only when the Management Server discovery finally considers the CentOS machine worth managing, then the other discoveries that use WS-Man queries start kicking in, like the old one did, and find the OS objects and all the other hosted objects. In order for this to work you don’t only need to hack the shell script, but to have a hacked MP – the “regular” Red Har one won’t find CentOS, which is and remains an UNSUPPORTED platform.

CentOS Health Model

Disclaimer

The information in this weblog is provided “AS IS” with no warranties, and confers no rights. This weblog does not represent the thoughts, intentions, plans or strategies of my employer. It is solely my own personal opinion. All code samples are provided “AS IS” without warranty of any kind, either express or implied, including but not limited to the implied warranties of merchantability and/or fitness for a particular purpose.
THIS WORK IS NOT ENDORSED AND NOT EVEN CHECKED, AUTHORIZED, SCRUTINIZED NOR APPROVED BY MY EMPLOYER, AND IT ONLY REPRESENT SOMETHING WHICH I’VE DONE IN MY FREE TIME. NO GUARANTEE WHATSOEVER IS GIVEN ON THIS. THE AUTHOR SHALL NOT BE MADE RESPONSIBLE FOR ANY DAMAGE YOU MIGHT INCUR WHEN USING THIS INFORMATION. The solution presented here IS NOT SUPPORTED by Microsoft.

CentOS 5 Management Pack for OpsMgr SCX

As I mentioned here, I have been testing the SCX beta.

Not having one of the “supported” platforms pushed me into playing with the provided Management Packs, and in turn I managed to use the MP for Red Hat Enterprise Linux 5 as a base, and replaced a couple of strings in the discoveries in order to get a working CentOS 5 Management Pack.

CentOS_HealthExplorer01_NEW

I still have not looked into the “hardware” monitors and health model / service model, so those are not currently monitored. But it is a start.

A lot of people have asked me a lot of information and would like to get the file – both in the blog’s comment, on the newsgroup, or via mail. I am sorry, but I cannot provide you with the file, because it has not been throughly tested and might render your systems unstable, and also because there might be licensing and copyright issues that I have not checked within Microsoft.

Keep also in mind that using CentOS as a monitored platform is NOT a SUPPORTED scenario/platform for SCX. I only used it because I did not have a Suse or Redhat handy that day, and because I wanted to understand how the Management Packs using WS-Man worked.

This said, should you wish to try to do the same “MP Hacking” I did,  I pretty much explained all you need to know in my previous post and its comments, so that should not be that difficult.

Actually, I still think that the best way to figure out how things are done is by looking at the actual implementation, so I encourage you to look at the management packs and figure out how those work. There are a few mature tools out there that will help you author/edit Management Packs if you don’t want to edit the XML directly: the Authoring Console, and Silect MP Studio Lite, for example. If you want to delve in the XML details, instead, then I suggest you read the Authoring Guide and peek at Steve Wilson’s AuthorMPs.com site.

Disclaimer
The information in this weblog is provided “AS IS” with no warranties, and confers no rights. This weblog does not represent the thoughts, intentions, plans or strategies of my employer. It is solely my own personal opinion. All code samples are provided “AS IS” without warranty of any kind, either express or implied, including but not limited to the implied warranties of merchantability and/or fitness for a particular purpose.
THIS WORK IS NOT ENDORSED AND NOT EVEN CHECKED, AUTHORIZED, SCRUTINIZED NOR APPROVED BY MY EMPLOYER, AND IT ONLY REPRESENT SOMETHING WHICH I’VE DONE IN MY FREE TIME. NO GUARANTEE WHATSOEVER IS GIVEN ON THIS. THE AUTHOR SHALL NOT BE MADE RESPONSIBLE FOR ANY DAMAGE YOU MIGHT INCUR WHEN USING THIS PROGRAM.

Create a Script-Based Unit Monitor in OpsMgr2007 via the GUI

Warning for people who landed here: this post is VERY OLD. It was written in the early days of struggling with OpsMgr 2007, and when nobody really knew how to do things.
I found that this way was working – and it surely does – but what is described here is NOT the recommended way to do things nowadays. This post was only meant to fill in a gap I was feeling existed, back in 2007.
But as time passes, and documentation gets written, knowledge improves.
Therefore, I recommend you read the newly released Composition chapter of the MP Authoring Guide instead
http://technet.microsoft.com/en-us/library/ff381321.aspx – and start building your custom modules to embed scripts as Brian Wren describes in there, so that you can share them between multiple rules and monitors.

This said, below is the original post.

Create a Script-Based Unit Monitor in OpsMgr2007 via the GUI

There is not a lot of documentation for System Center Operations Manager 2007 yet.
It is coming, but there’s a lot of things that changed since the previous release and I think some more would only help. Also, a lot of the content I am seeing is either too newbie-oriented or too developer-oriented, for some reason.

I have not yet seen a tutorial, webcast or anything that explains how to create a simple unit monitor that uses a VBS script using the GUI.

So this is how you do it:

Go to the “Authoring” space of OpsMgr 2007 Operations Console.
Select the “Management Pack objects”, then “Monitors” node. Right click and choose “Create a monitor” -> “Unit Monitor”.

You get the “Create a monitor” wizard open:
wizard02

Choose to create a two-states unit monitor based on a script. Creating a three- state monitor would be pretty similar, but I’ll show you the most simple one.
Also, choose a Management pack that will contain your script and unit monitor, or create a new management pack.
wizard03

Choose a “monitor target” (object classes or instances – see this webcast about targeting rules and monitors: www.microsoft.com/winme/0703/28666/Target_Monitoring_Edit… ) and the aggregate rollup monitor you want to roll the state up to.

Choose a schedule, that is: how often would you like your script to run. For demonstration purposes I usually choose a very short interval such a two or three minutes. For production environments, tough, choose a longer time range.
wizard04

Choose a name for your script, complete with a .VBS extension, and write the code of the script in the rich text box:
wizard05

As the sample code and comments suggest, you should use a script that checks for the stuff you want it to check, and returns a “Property Bag” that can be later interpreted by OpsMgr workflow to change the monitor’s state.
This is substantially different than scripting in MOM 2005, where you could only launch scripts as responses, loosing all control over their execution.

For demonstration purpose, use the following script code:
 

On Error Resume Next
Dim oAPI, oBag
Set oAPI = CreateObject(“MOM.ScriptAPI”)
Set oBag = oAPI.CreateTypedPropertyBag(StateDataType)
Const FOR_APPENDING = 8
strFileName = “c:\testfolder\testfile.txt”
strContent = “test ”
Set objFS = CreateObject(“Scripting.FileSystemObject”)
Set objTS = objFS.OpenTextFile(strFileName,FOR_APPENDING)
If Err.Number <> 0 Then
Call oBag.AddValue(“State”,”BAD”)
Else
Call oBag.AddValue(“State”,”GOOD”)
objTS.Write strContent
End If
Call oAPI.Return(oBag)

[edited on 29th of May as pointed out by Ian: if you cut and paste the example script you might need to change the apostrophes (“) as that causes the script to fail when run – it is an issue with the template of this blog.] [edited on 30th of May: I fixed the blog so that now post content shows just plain, normal double quotes instead than fancy ones. It seems like a useful thing when from time to time I post code…]

The script will try to write into the file c:\testfolder\testfile.txt.
If it finds the file and manages to write (append text) to it, it will return the property “State” with a value of “GOOD”.
If it fails (for example if the file does not exist), it will return the property “State” with a value of “BAD”.

In MOM 2005 you could only let script generate Events or Alerts directly as a mean to communicate their results back to the monitoring engine. In OpsMgr 2007 you can let your script spit out a property bag and then continue the monitoring workflow and decide what to do depending on the script’s result.

wizard06

So the next step is to go and check for the value of the property we return in the property bag, to determine which status the monitor will have to assume.

We use the syntax Property[@Name=’State’] in the parameter field, and we search for a content that means an unhealthy condition:

wizard07

Or for the healty one:
wizard08

Then we decide which status will the monitor have to assume in the healty and unhealty conditions (Green/Yellow or Green/Red usually)
wizard09

Optionally, we can decide to raise an Alert when the status changes to unhealthy, and close it again when it goes back to healty.

wizard10

Now our unit monitor is done.
All we have to do is waiting it gets pushed down to the agent(s) that should execute it, and wait for its status to change.
In fact it should go to the unhealthy state first.
To test that it works, just create the text file it will be searching for, and wait for it to run again, and the state should be reset to Healthy.

Have fun with more complex scripts!

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