Green Folly

Poor man’s file compare with Powershell

23 June 2008, 6:41 pm

Frustration levels went high today as I was burned by another bad config in our prod environment. While we wait for a more robust config file management tool that will handle all our web app configs and service configs, we have relied on a Powershell script that stages code for prod and tweaks the config files so that any environment specific changes for prod are made. In the latest case, a bad config was checked into our repository and the Powershell script failed to catch the new pattern. To get around running a diff tool against each file before each release (we have dozens of configs), I wrote the following script that serves as an indication as to what files are out of sync. Operations can now run this script to understand what config changes are about to happen.

function CompareFileContents([string]$filepath1, [string]$filepath2, [string] $logFile)
{
write-output “Comparing $filepath1 to $filepath2″ | out-file $logFile -append
Compare-Object -referenceObject $(Get-Content $filepath1) -differenceObject $(Get-Content $filepath2) -syncWindow 0 | out-file $logFile -append
}

$date = Get-Date
$configDiffLogFile = “D:\builds\ConfigFileCompare{0}{1:d2}{2:d2}-{3:d2}{4:d2}.txt” -f $date.year,$date.month,$date.day,$date.hour,$date.minute
write-output “The config file diff output will be stored at $configDiffLogFile”

CompareFileContents \\qapapp01\e$\SAJServices\ReleaseStage\PriorRelease\svc\SnagAJob\SAJ.EmployerSearch\SnagAJob.EmployerSearch.WinHost.exe.config \\qapapp01\e$\SAJServices\ReleaseStage\ReleaseToDeploy\svc\SnagAJob\SAJ.EmployerSearch\SnagAJob.EmployerSearch.WinHost.exe.config $configDiffLogFile

Couple of items on the script:

The “-syncWindow 0″option ensures that each lines match sequentially. So if someone moves a line further down in the difference file, even though it has a match in the reference file, the change will be logged.
The filename format came from this post about a nifty way to use the -f format operator

Filed under Powershell, Tech. Tagged file compare, Powershell, windiff

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Thoughts on volunteering at Special Olympics

7 June 2008, 8:43 pm

Yesterday I had the chance to help out at a Special Olypmics event that was held at the University of Richmond. A coworker at SnagAJob.com had broadcast a need for volunteers. Her sister was the coach for the Area 26 team out of Northern Virginia. I was attempting to volunteer as a chaperon but somehow my volunteer form was “lost in the mail” so I was not able to volunteer in that capacity. Nevertheless, I was able to help the coach out during the day.

I essentially functioned as gopher for the coach and a supervisor for the atheletes while they waited for there events to start. Even though the weather was extremely hot and humid (97 degrees and 80% humidity), the athletes were ready to roll. I met some wonderful people and passed the time via long converstations with some of the athletes (namely David and Catie). I was interested in one of the athletes, Bruce, who looked to be in a trance as he ran a very effective 1500m race (good pace, especially in the heat). I hope I can reach that level of calmness during my training.

Overall, I was impressed with the motivation of the athletes and the show of support that the athletes showed for each other. In addition, one of the athletes on a different team was most definitely an elite athlete. She was fast while competing in the pentathlon and I found out from one of the other parents that she had completed a marathon. Regardless of their level of disabilities, the simple ability to train and ultimately compete in these type of adverse weather conditions was very impressive. I am glad that I was able to help out in a small way.

Filed under General.

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Helpful hints on connecting to Cisco VPN on Ubuntu Hardy Heron

7 June 2008, 8:23 pm

The Long Story

You can get to the Short Story by scrolling down

After getting a new wireless router and moving my desktop PC (running Windows XP) upstairs to the hallway, I went to work getting my VPN connection to SnagAJob.com up and working again. My plan was to try it out from the desktop PC (which worked when it was directly connected to the cable modem) and ensure that the VPN connection worked over the wireless network. Afterwards, I would then try to get a the Cisco VPN client working on my laptop, which is running Ubuntu (v8.04).

I was completely unsuccessful in getting my XP box to connect to the VPN client. The client would attempt to initialize the connection but would fail each time. The obvious culprit must have been the router. I am using the Netgear WPN824v3 Rangemax router. I tried changing the following settings on the router but with no success:

turned off the SPI (stateful packet inspection) firewall
turned off NAT filtering
turned on “respond to ping requests from the internet”
turned on port forwarding that are relevant for my type of VPN connection.

After a few hours of increasing frustrating results and feeling strangely exposed to the bad boys on the internet, I let things idle for a while. A couple days later, I attempted to connect to the VPN using my laptop. I wanted to use the Cisco VPN client and found the following instructions (http://www.longren.org/2007/05/17/how-to-cisco-vpn-client-on-ubuntu-704-feisty-fawn/). However, the instructions make clear that the client would not work on my version of the Linux kernel.

Feeling dejected and alone (and still exposed), I searched for other VPN clients that would work. Very quickly, I found that KVpnc (http://home.gna.org/kvpnc/en/index.html) may work. I installed that and then installed the free Cisco client, vpnc (http://www.unix-ag.uni-kl.de/~massar/vpnc/) using the Synaptic Package Manager. I fired up KVpnc and imported the Cisco client profile for my VPN connection (*.pcf). I selected the imported profile and went to connect. Success! I then started dialing back all the router changes I made and testing connectivity after each change. Each time, I was successful in connecting.

Next on the list was to remote desktop into my work machine so I could access my dev environment. I fired up rdesktop and tried to connect to my work machine over port 3389. I had no luck. After a little more searching, I found that the tsclient program was better suited for my needs. I fired that up and entered the relevant info. I experimented with different resolution sizes, but ended up selecting the full screen option. I was able to remote into my work PC. However, I had no way to get back to my local desktop. Tsclient does not have a toolbar like the Windows version does. I could log off my work PC to end the session but I like to toggle from local to remote a lot during a work day. After more searching, I found that Ctrl+Alt+enter should toggle me back to my local PC. I did this and the screen flickered to the local workspace and then went back to the remote PC. After more searching (as an aside, I would be a complete idiot without Google search – I need a direct neural interface to their search engine) I found that this behavior was due to a bug in rdesktop. It appeared to revolve around the Desktop Effects feature that makes things “pretty”. There were a multitude of workarounds suggested but after reviewing these, it seemed the most practical solution was to just turn off desktop effects altogether. Just like I want my coffee black, I like having a desktop that is “effect free” I kept the OS default desktop effect option up until now since it did not appear to impact system performance, but this rdesktop bug was a great excuse to turn the effects off. After turning the Desktop effects off, I was able to use the Ctrl+Alt+Enter key combo to toggle from local to remote. Finally!

I still have not had success in getting my XP desktop to connect to my work VPN. I am giving up on that box since my laptop now works.

The Short Story

To connect to a Cisco VPN from Ubuntu 8.04 (note that there are different Cisco VPN configs out there. These steps worked for me but mileage may vary).

Environment

Ubuntu 8.04 (Hardy Heron) on local machine
Windows 2003 server on remote machine
Wireless network with Netgear WPN824v3 Rangemax router – default router options
Cisco VPN (unsure of exact type used at work)
Already have a known Cisco client profile that works in XP (when directly connected to local cable modem)

Assumptions

You know how to install applications on Ubuntu using the Synaptic package manager or the Applications → Add/Remove feature. If not, see

Steps used to connect to VPN

Open up first bottle of Sam Adams, take small swig
Install KVpnc using the Synaptic package manager or using the Applications → Add/remove feature
Copy your Cisco client profile from your Windows box to a directory on your Ubuntu installation
Run KVpnc (should be located at Applications → Internet) and select Profile → Import Cisco pcf file. Navigate to the location where you stored the pcf file and select it. Click OK.
Install vpnc using the Synaptic package manager or using the Applications → Add/remove feature
In KVpnc, go to Settings → configure kvpnc and select “Daemons” under “Programs”.
Check that the path used for vpnc is correct and that it points to where the vpnc program was installed to. Once you are set, click OK.
Get another beer.
On the main kvpnc window, you should see a Profile dropdown that has the name of the profile you imported. Select that profile and click Connect.

You should now be connected.

If you want to remote desktop into a another PC follow the following steps:

Go to System → Preferences → Appearance
Go to the Visual effects tab and select “None”. Click Close.
1. If you really are attached to the visual effects used in Ubuntu, you can try the workarounds located at https://bugs.launchpad.net/ubuntu/+source/rdesktop/+bug/153995. I have not tried them and do not know if they work.
Run tsclient (Applications → Internet → Terminal Server Client)
Click the Display tab.
Select “Operate in full screen mode”
1. Note: you can select your own resolution as well here. The default was 800×600 but that just doesn’t fly with me.
2. Note 2: Do not click “use alternate full screen switch”. It added an invalid command to the command list for rdesktop and hosed the connection attempt
Go back to the General tab and enter the computer name and your user name and password. You can save this info via the “Save As” button. Once you do this, the profile will be available under the “Quick Connect” dropdown
Click Connect
Get the nachos and another beer if you are so inclined.
Sit back back down and wonder if the ability to log back into work from home is such a good thing after all.

Filed under ubuntu. Tagged cisco, Hardy Heron, rdesktop, tsclient, ubuntu, vpn

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