Jan 01 2013

Ditching Vino for X11vnc

Category: Systems — jgoulah @ 2:07 PM

I’d been using gnome vino as a VNC server for years on my media computer. This way I can use touchpad to control it from my iPad. It works fine, but a little bit clunky and badly documented, plus its tied directly to gnome. The other day I woke up to a filled drive (~2TB) of vino errors. I killed it off and cleaned up the error log file and tried to start it up again. No go this time due to some startup errors. This isn’t the first time I’ve fought with it, surely something better exists.

This led me to X11vnc. A bit of fresh air its fairly easy to setup and get going very quickly. I’ll first show how to do it manually and then present my open sourced chef cookbook.

Manual Install

First thing is to install it:

sudo apt-get install x11vnc

Setup a password file:

sudo x11vnc -storepasswd YOUR_PASS_HERE /etc/x11vnc.pass

Create an upstart config:

sudo touch /etc/init/x11vnc.conf

Open it and put this into it:

start on login-session-start
script
x11vnc -xkb -noxrecord -noxfixes -noxdamage -display :0 -rfbauth /etc/x11vnc.pass \
 -auth /var/run/lightdm/root/:0 -forever -bg -o /var/log/x11vnc.log
end script

and start it up:

sudo service x11vnc start

Simple, easy, and just works.

Chef Cookbook

Naturally, I ported this to a chef cookbook which you can find here. I have to admit I’m not totally happy with it yet, mainly because it doesn’t restart x11vnc on config changes. In some cases such as our production servers, we actually prefer this so that we don’t accidentally roll out a broken config change and have an auto-restart bring everything to its knees (there are some ways to avoid this but thats another post). In any case on my home computer I prefer it to restart if I make changes, but I’m struggling to get upstart to stop the process correctly due to what seems to be some disassociation with its pid file. The other thing is the recipe currently assumes you are using Ubuntu or something similar, but can easily be extended. Hope this helps someone else out there!

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Jul 20 2012

Development is Production Too

Category: Conferences — jgoulah @ 8:56 PM

I was at OSCON this week, and my friend Erik Kastner and I did a talk about development environments. Specifically what to avoid and how to keep environments consistent across development and production. As usual the slides are not fully explanatory without seeing the accompanying talk but here they are anyway:

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May 28 2012

Using the New “load_recipe” Chef Function with Shef

Category: Coding — jgoulah @ 9:21 PM

If you are developing chef recipes it really helps to use the command line tool called shef. Shef is just a REPL to run chef in an interactive ruby session. If you haven’t ever tried it, you can find some nice instructions over here to get you going.

Shef gives an easy way to iterate on your recipes so that you can make small changes and see the effects. However, I found the include_recipe function would only load the recipe one time, and complain that its seen the recipe before on subsequent tries. I added a small patch that implemented a new function called load_recipe that will allow you to reimport the recipe. The problem is that once the recipe is loaded again, the resource list is reimported giving us the same set of resources twice.

You can see the list of resources that are loaded up like so

chef:recipe > puts run_context.resource_collection.all_resources
package[php]
package[php-common]

If you were to call load_recipe again the list would double, and the new code would be run second when calling run_chef

chef:recipe > puts run_context.resource_collection.all_resources
package[php]
package[php-common]
package[php]
package[php-common]

The trick is that you can clear this list with this command

run_context.resource_collection = Chef::ResourceCollection.new

So to use load_recipe you should call the above before it to clear the current list. This can be done in one line like so

run_context.resource_collection = Chef::ResourceCollection.new; load_recipe "php"

Hopefully I’ll be able to patch things to add a reload_recipe that overwrites the old resources so you don’t have to use this trick, but for now this will work to get quick iterations going.

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