Puppet Fact Fix after Ruby 1.9 upgrade

Stardate: 90683.2
We recently upgraded our entire infrastructure to Puppet 3. As if that wasn't ambitious enough (though I suppose Puppet 3.1 has an rc), we are slowly bringing ruby to 1.9 from 1.8.7. Surprisingly, puppet actually works under ruby 1.9. This blows my mind since I remember having to do some seriously ugly hacks to get puppet working under ruby 1.9. Unfortunately, and embarrassingly, one of my custom facts was not forward compatible.

...
Info: Loading facts in /var/lib/puppet/lib/facter/nvidia_graphics_device.rb
Could not retrieve dns_ip_6: undefined method `each' for "yermom.cat.pdx.edu has address 131.252.222.10\n":String
Could not retrieve dns_ip_6: undefined method `each' for "yermom.cat.pdx.edu has address 131.252.222.10\n":String
...

The unfortunate cause of this (other than that I didn't write 1.9 compatible code) is that string.each has been removed from ruby as of ruby 1.9. :(
For those of you unfamiliar with puppet hacking, most testing should be done through git dynamic environments. Unfortunately, there is a bug in puppet that prevents facts from being able to be tested on any branch but production. You can add the facts to git and push them to the environments directory on the puppet master, but unless they are in branch production you won't see them get filebucketted or run.
So what to do? The answer is to develop on the box itself, usually as root, though sudo is an idea. (Hopefully I can get a friend of mine to guest post on why sudo is the correct way to attain root privileges for administration, and I can counterpost on why su - is the correct way.) On ubuntu (as of 12.04, anyways) the puppet configuration dir is /etc/puppet, but the puppet var dir is /var/lib/puppet. Facts live in /var/lib/puppet/lib/facter. The best way to get information on a current puppet's installation and configuration is through:

puppet config print all | grep vardir
vardir = /var/lib/puppet

Change directory to the puppet vardir and modify the facts in place. Then run the facter utility with the '-p' argument. The '-p' argument tells facter to run all its normal facts as well as facts loaded in from puppet.

root@yermom:/var/lib/puppet/lib/facter# facter -p | grep dns
dns_ip_4 => ["131.252.222.10"]
dns_ip_6 => []

Fantastic. All is well again.

Irc Bots in Twisted with Invite-only Channels

Stardate: 90672.08

I'm kind of obsessed with writing irc bots in python using twisted.words.protocols. A longer example of how to do that may come later but for now I want to show you one of the best ways to debug your twisted irc bot and a vector to get really cool behavior not intended by the twisted developers. On an IRC server I frequent channels that are secured by forcing users to first login with NickServ then to ask ChanServ for an invite. The problem is you must join the channel after your receive the invitation from ChanServ. My solution to this problem is below, using irc_UNKNOWN and the ircLogBot.py example in the twisted.words documentation:

class BeerBot(irc.IRCClient):
    """A logging IRC bot."""
    """That also does beer things."""

...


    def signedOn(self):
        """Called when bot has succesfully signed on to server."""
        self.logger.log('identifying to nickserv')
        self.msg("NickServ", "identify %s" % config.password)
        self.logger.log('requesting channel invite')
        self.msg("ChanServ", "invite %s" % config.channel)
        self.join(self.factory.channel)
        self.logger.log('channel joinied')

...


    def irc_unknown(self, prefix, command, params):
        self.logger.log("{0}, {1}, {2}".format(prefix, command, params))
        if command == "INVITE":
          self.join(params[1])

The irc_unknown is great because it simulates the 'window 1' on most irc clients(well most command line irc clients[and by that I mean weechat and irssi{and by that I mean irssi-for-life!}]). You can add if statements to grab the other 'named' irc control messages. The others are numbered and you can split those out as well. One of the bad things about irc is different irc servers behave differently. It must be a frustrating and thankless task for the maintainers of irssi/weechat/t.p.w to provide such a universal interface to all irc servers. (lol jk, irssi hasn't had an update since like 2010.) [but no really, thank you irssi devs *internet hug*].

The source code for beerbot can be found at my github.