Node.js – building massively parallel applications with javascript and epoll

Node.js [http://nodejs.org/] is a framework for rapidly building massively parallel network applications using non-blocking io. It’s built on the performant v8 javascript engine [http://code.google.com/p/v8/] which compiles javascript to machine code at runtime. Node is similar in design to systems like Ruby’s EventMachine [http://rubyforge.org/projects/eventmachine/] or python’s twisted [http://twistedmatrix.com/trac/]. It’s suitable for building chat-like protocols, comet servers, mmo game servers, etc. This session will cover some of the basics of how to build and install node.js as well as analyze some demo programs.

If time permits, I might talk a little bit about python’s twisted and compare some programs written using twisted/node.js

About Shane Hansen:

I’m a Software Engineer working on Backcountry.com’s replatforming teams. Prior to that I worked on projects ranging from compliance tracking software for the goverment to building  mathematical models for reflectometry to immune system modeling. I’m interested in open source software, web standards, high performance computing and application architecture

Meeting Location:

BetaLoft (http://betaloftslc.com) is located at 357 W 200 S. Upstairs in Suite 201. Salt Lake City, UT, 84101

Betaloft is a coworking space in the heart of downtown Salt Lake City founded by Drew Tyler.

We are a community of freelancers, independents and work-from-home people, who have an interest in getting out of our dull work day and participating in a community that’s designed to support and encourage people who make a living doing what they love.

We provide communication tools, events (social and educational), as well as a physical space to work and collaborate.

See you all there!

Clint

Today, I found myself needing to enable the network (using dhcp) from the anaconda command line (the part that says boot: when you load a CentOS/RHEL/Fedora install disk).

I needed this because I was providing a bit of local media to our external employees for them to use to install, but I had 3 yum repositories I wanted them to be able to use for a few additional rpms I provided.

So, I popped into one of my common support channels and asked the question:

16:11 < herlo> looking for an option that I can put on the anaconda boot: prompt that will force a
               dhcp request even though the install is from a local disk.  I have repos that are not
               being accessed because the network is not being enabled.
16:11 < herlo> things I have tried
16:11 < herlo> ip=dhcp
16:12 < herlo> boot: linux noipv6 ks=hd:sdb1:media/kickstart.cfg ip=dhcp
16:20 < herlo> okay, so for those who might care
16:20 < herlo> if you do
16:20 < herlo> boot: linux asknetwork ip=dhcp noipv6 ks=hd:sdb1:media/kickstart.cfg
16:20 < herlo> anaconda will force a network dhcp request :)
16:20  * herlo is happy again

As you may have noticed above, I resolved this issue without any assistance from the channel, and it only took me 10 minutes to do so.  I found my answer by trial and error from a great page on the fedora wiki: https://fedoraproject.org/wiki/Anaconda/Options

Probably the only thing I wish was documented on that page was when each of the options started being supported in anaconda.  Otherwise, thank you to the folks that wrote and maintain that page.

Cheers,

Herlo

As usual, come from 11:30am-1pm at BetaLoftSLC (357 W 200 S #201)  - http://betaloftslc.com

This month, I thought I would share a basic git introduction.  In my opinion, the best Source Control Management (SCM) system out right now.  I’ve been using it for nigh on a year and I have converted a few systems over to it from svn.  This is more of a work session than a presentation, so come on down and learn how to use git.  It is recommended that you bring your laptops with you as that will benefit more if you do.

Some suggested topics I can cover:

• Local and remote git repositories (different workflows and other fun stuff)
• Using git-svn to ‘convert’ from svn
• Comparing Distributed Revision Control with Traditional (non-distributed) Revision Control
• Git hooks, why they are valuable and when to use them
• Other basic git discussions

See you all there.

Cheers,

Herlo

Everything Just Works(TM).

I highly recommend it to anyone who wants to have a system working with great sound, awesome graphics and very usable GNOME and KDE desktops.  I really like the new NetworkManager features and the ability to tether any device, vpnc and other easy-to-configure options.  KVM support is much improved with the new libguestfs improvements.

Fedora 12 media should be available on December 3, if you are a Fedora Ambassador in North America, start requesting media* for your events (and ambassador kits).

You can get your copy today!!

Cheers,

Herlo

*NOTE: This request page is not for the freemedia project. You must be a Fedora Contributor to request media.  Join the Fedora Project today and help us continue making Fedora the best operating system!!

To do this, I’ve been using a centralized git repository using gitosis and gitweb.  Because it’s behind the Backcountry firewalls, there is no easy way to share our repository data.  However, there are some great git repos at github, which I highly recommend.

Anyway, we do the hub-and-spoke model with our git repositories.  Meaning that we have a central repository where much of the data is stored so everyone can get access.  Of course, though, most people clone these repositories and work on the code where they choose.  Because we have several people pushing puppet data to our repository, which has been on subversion until 2 weeks ago, I am keen on making sure the puppet code we push to the central repo is at least syntactically valid.

Git Hooks: The skinny

Essentially, the key here is to understand is that git, like many other popular revision control systems is distributed.  This means that many people keep repos locally and push to the central repository after many many commits (or just one or two).  Git keeps the history in a clean way and all of the commits are pushed and tracked.  Essentially, we need some way to validate the data coming in from an outside source.  Enter git hooks.

There are several git hooks, but three that are quite critical to this scenario; pre-commit, pre-receive and post-receive.

The first, pre-commit is specific to the repository where the commit is taking place, such that a validation of the puppet syntax here is useful to help the person writing the puppet rules.

Next is post-receive which is generally useful for sending out emails after a successful push.  It would list the files and the diff of each in an email to those who wish to know about the commit.

And finally, the least documented of the bunch; the one with the least amount of examples, pre-receive.  The pre-receive hook has some really awesome power, but without knowing the git commands backward and forward, it can be very frustrating to get working.

The value of the pre-receive hook

Whenever a push is made to the centralized repository, you don’t just want to let any willy nilly commit crawl in there.  You can’t trust that the author of the commits did his part to validate the code.  So you need to at least do some basic checks.  That is what the pre-receive hook does.  In the following example, I am parsing files that end in ‘.pp’ with puppet syntax validation as you would do from the command line.

#!/bin/bash

while read old_sha1 new_sha1 refname anothervalue ; do
    list=$(git show --pretty="format:" --name-only $new_sha1 | grep -e ".pp$")
    for tmpfile in ${list}; do
        git show ${new_sha1}:${tmpfile} | puppet --color=false --confdir=/tmp --vardir=/tmp --parseonly --ignoreimport
        if [ "$?" -ne "0" ]; then exit 1; fi
    done
done

exit $?

The above script, placed in a bare repository at hooks/pre-receive with the execute (+x) bit turned on, will get a list of files that end in ‘.pp’ and run the puppet validator for the newest commit in the push.  Essentially, I can validate someone else’s puppet code in just a few seconds and return a failure if it doesn’t succeed.  With git hooks, a failure means no commit/push/etc will actually happen.

I sure hope this helps someone else to understand pre-receive hooks as well as git hooks in general.  If you have any helpful suggestions or comments, those are most welcome as well.

Cheers,

Herlo

Thank you UTOS Core Team

In addition, it’s been great to have a Conference Manager this year.  Will Smith (aka undertakingyou) has taken these reigns with fire and he’s really picked up the leadership role.  Thank you Will for doing an amazing job.  I know his role will continue to grow as we start our transition into a 501c3 this year, I am excited to have him leading the Core Team charge!

I would also like to recognize the hard work of Barry McCormick.  He’s been a bulldog at getting our program together this year.  His hard work, dedication and shear will has made this years conference program the best I’ve seen.  50+ presentations, several events, scheduling requests, etc.  Even through the flu last week, he was finalizing details.

We have an awesome art and marketing team.  Victor Villa heads up this department, with contributions from Velda Christensen (and former Core Team member Emily Shaw).  I want to thank each and every one of you for your hard work and dedication to detail and spreading the open source love around the Mountain West.

Jason Hall is heading up our volunteer efforts this year.  As the emcee again, we’re excited to have a volunteer manager that will assign and maneuver 50+ volunteers.  The call for volunteers has officially closed, but there’s always 2010.  Come and see the volunteers at work, Jayce^ has them all lined up and ready to go!

While we’ve had some bumps and bruises with our sponsorship position, Justin Carmony has really stepped in to make that role work.  We’ve been able to secure some really good sponsorships this year due to his hard work.  I’m excited to see what the future hold with our sponsorships and Justin at the helm.

Our Network is going to be stellar again this year.  I don’t know of any free software community conference that can boast 100mb/s lines, free wifi and drops to every booth in the convention center.  Trevor Sharpe (Heartsbane) and Nick Brooks (peno) have done an amazing job with this as well.

Securing our parties, getting printable schedules, providing the topics with which our emcee will hand out SWAG, talk about different organizations, introduce presenters and talk about our sponsors is C.R. Oldham.  C.R. joined the core team as an effort to bolster another group, HopeKids, which he will do during the conference.  He’s been a great asset to our core team and we look forward to seeing him for years to come.

And finally, because well, he’d want it that way.  Without our Code Guru, Adam Barrett, the website would look a little bare (or bear, since that’s his nickname).  The site would probably be still in a state of disarray and those schedules, layouts with all the pretty boxes and such would not be there.  He’s working on some more amazing things each week as we meet for our HackNights (which anyone is welcome to attend).  I suspect you’ll see some really cool features at the conference that are part of Adam’s evil plan.

This is the Utah Open Source Core Team.  If you see them at the Utah Open Source Conference, please take a moment to thank them for their hard work.  I know that I will!!

Please register today, we have a few days left before the prices go up.  Promo codes are available for up to 50% off registration at any time.  Contact a LUG or Sponsor if you would like a promo code for discounted registration.

Cheers,

Herlo

21:37 <herlo> did you say you were willing to cook breakfast for us during UTOSC ??
21:37 <herlo> :-P
21:37 <herlo> I couldn’t remember if you agreed, or balked
21:37 <Jennifer> I did. I will make sure I don’t work so I can do it properly.
21:37 <Jennifer> 5 people, right. Plus us, of course.
21:38 <Jennifer> ?
21:38 <herlo> yeah
21:38 <Jennifer> Yep, for 3 days? I can do that. :)
21:38 <herlo> so far, I have Ian, Scott, Larry and Mirano and possibly Scott (from LA)
21:39 <herlo> it does mean that it has to be ready kind of early though…
21:40 <JenniferDean> Yep
21:40 <herlo> kk, grerat!
21:40 <herlo> or just great!
21:40 <JenniferDean> That’s what prep the night before is for
21:40 <herlo> lol, yeah
21:41 <JenniferDean> The only rule is: stay out while I’m cooking. Lol

So as you can see, I just had to comment about it right now!  Jennifer is awesome!

Looks like our guests will be well taken care of during UTOSC 2009!!

See you all there! October 8-10, 2009.  Register today!

Cheers,

Herlo

We have a great presentation lined up for you all!  Here’s the details:

Infrastructure Renaissance

Open source is at the forefront of an evolving ecosystem of tools and processes for building more adaptable and maintainable computational infrastructure. Virtualization and network booting tools speed up and simplify the process of provisioning. Configuration management tools provide policy based service descriptions which collapse the complexity of scaling. Monitoring solutions provide feedback which potentially drive provisioning and configuration. For organizations to fully leverage these tools is often as much a social engineering problem as a technical one. This talk is about building computational infrastructure with the tools, and processes that can help maximize the benefits.

About Andrew

Andrew Shafer is a Co-founder of Reductive Labs Inc., helping organizations build more flexible and scalable systems through better tools and processes with the Open Source system management framework, Puppet™. He brings with him a background in computational science, embedded Linux development, web frameworks and Agile methods.  Currently, Andrew is devoted to AR⊗TA (arxta.net, watch the video). Andrew has been an Open Source user and advocate since the late 90s. His two sons think he is pretty cool.

See you all this Wednesday.

Cheers,

Herlo

This month’s SLLUG Daytime SIG meeting is this coming Wednesday, July 8, from 11:30am-1pm at BetaLoft.  I apologize for being slow getting this out, we’ve been working through a big datacenter move this past week at work.  Now that is over, it’s time for SLLUG Daytime at BetaLoft, (357 W 200 S Suite 201 Salt Lake City, UT, 84101).  Here’s a map if you need directions.

I’d like to let you all know that I (Herlo) will be presenting this month, and the topic is: Cobbler, the powerful, installation, dhcp, dns and repo server!

If you have ever wanted to setup a system with pxe, dhcp, customized repositories and more, then cobbler is for you.  Feel free to read up on the cobbler website before the meeting.

I should mention that cobbler supports several distributions of Linux, and will soon support Windows remote installation (using Linux RIS).  Albeit, I’ll focus on setup of cobbler, a simple installation server with just one distro, using kvm and koan (kickstart over a network) with some basic networking and showing the gui tools as well.

Bring your lunch and your brains and learn all about setting up your very own install server in under an hour.

See you all on Wednesday!

Cheers,

Herlo

Now that I am back from the SouthEast LinuxFest at Clemson University, I wanted to report on the fun we had this weekend.  I’m completely wiped out, but it was a very fun and productive weekend.  I wanted to say thanks to the gang at SELF for a job well done.  With only minor issues, they did an amazing job.  They’re first year conference had attendance of 500+, that’s great to hear!  Congratulation on such a great conference fellas!!

As far as my presentation, I was the victim of an apparent overheating of the projector.  After about 20 minutes of fiddling, the staff got it all solved with a portable projector that was waiting in the wings.  This did affect the time on my presentation though, so i wasn’t able to finish everything I wanted.  However, we did a lot of Q&A up front and helped explain some of the four foundations from the Fedora Project and talked a bit about the tools while we were waiting.  I usually show a completed customized liveusb, but ran out of time.  I hope everyone enjoyed it anyway.

The booth area was packed, and every presentation seemed full, it was a great conference.  I went to the after-party, where DualCore rapped for a while, which is always fun.  The rest of the night was drinking, socializing and having an altogether good time.  I recall eating at waffle house around 12:30am and then heading back to the hotel for some much needed sleep.

On Sunday, we spent a good bit of time on the Docs Fedora Activity Day (FAD), quite productive and we made some good goals for F12.  I mostly helped by being an outsider looking in on this process, but did help Lee and Eric to understand packaging as Ian explained how packaging works.  It was great to help the docs guys get the rest of the modules for Zikula into Fedora.  I expect to see some good progress there over the next release period.

All in all, it was an awesome weekend, and if you ever get the chance, Mellow Mushroom pizza is the bomb!  I also took a lot of pictures, they are available up on Flickr.

Cheers,

Herlo