Ted Roche’s weblog

Nineteen people made May 5th’s CentraLUG meeting the second best attended of any LUG meeting so far this year, and the most populous CentraLUG meeting in over two years!

The meeting starting with a rag-tag band of Linux enthusiasts wandering around the campus looking for a room to meet. It’s finals week at NHTI and we’d been bumped from our regular spot. From the Library to the Crocker building to the Little Building we moved as more and more and more attendees arrived and we outgrew our first and second choices of rooms. Thanks to all for patience and multiple moves, and apologies for any folks we lost along the way.

The hassle was worthwhile, as Ben put on a great presentation on “The Linux Server That Could: Setting up a Small Office Server.” Over the years, both as part of his work and his hobbies, Ben has set up many multi-purpose computer servers: a single machine to serve a small workgroup with mail, files, printing, centralized DNS, DHCP. Ben had some slides to introduce the concepts and frame the problems his scripts solves, and then he dove into how to set up and configure the services. Providing a running commentary while he showed us configuration files, he offered a number of Best Practices tips for configuring, naming your intranet ‘domain,’ how CentOS/Red Hat family distros work, the differences in different flavors of Linux distros, editing configuration files, viewing error logs and more. It was a content-filled hour!

Slides and sample scripts and configuration files can be found on the GNHLUG web site here. Thanks to Ben for a great presentation, to Bruce Dawson for last-minute projector duty, to Bill Sconce for helping with the raffle, to the NHTI staff for helping us find facilities, and to all who attended and participated!

Found a couple of good leads on setting up the Koolu as a MythTV front-end, through persistent searching in specific forums, like the Ubuntu support forums and the MythTV mailing lists. A couple quick clues:

1. Hit DEL on startup to get into the BIOS, use the BIOS options to expand the memory dedicated to the video card. Options are: 32M, 64 M, 128 M. Not sure how much of an effect it will have.

2. Hit Shift-F10 early in the startup (prompt only appears for a second) to disable the RealTek attempt to launch the machine from a network boot image via PXE. This saves 10 or 20 seconds on every boot.

3. The /etc/fstab had an entry for a swap partition, but the UUID was incorrect. Just reassigning the device to hda5 rather than the UUID was enough to get the swap to come up.

4. I’m convinced there’s a way to get a lot more performance from the video, but need to dig in more. The AMD LX800 driver should support buffering, just need to find the trick to turn it on.

5. There’s an error in the Xorg.0.log file that indicates the kernel doesn’t support MTRR and should be recompiled to do that.

“1964: In the predawn hours of May Day, two professors at Dartmouth College run the first program in their new language, Basic.” Read the tribute at Wired.com

We all know the answer is “Developers, developers, developers, developers,” but who’s asking the question these days? It seems like Sun has taken up the song, according to Timothy M. O’Brien’s posting over at O’Reilly, “Surprising Contender: NetBeans as a Ruby+MySQL IDE.” Great news for all of us looking for new tools; NetBeans is shaping up to be a pretty sharp IDE.

I saw a blog post recently and neglected to bookmark it that posited the thesis that rich IDEs were bad when learning a language. A simple text editor and console can be all the interface you might need when when starting off and as your skills increased, the need for code completion, cross-referencing, inline debugging, source code control, refactoring and macros all became more valuable. Witness the training videos on http://www.rubyonrails.org where developers use a browser, a console window and the Textmate editor to build sample applications. The simplicity is appealing.

I’ve avoided spending too much time delving into Javascript. My four-year switch from Windows-uber-alles (including VFP, VSS, SQL Server, Ingres, Oracle, HTML, OLE, ODBC, SCC, COM, XML, MCSE, MCSD, XSLT, DCOM, RSS, MS Office, Exchange, MAPI Bad, SMTP Good, MVP and more acronyms!) to Linux-Apache-MySQL-Postgres-PHP-Python-Ruby, not to mention XHTML, CSS, bash, Smarty, Django, TWiki, dojo, et al had kept me busy enough. But a new client assignment needs a highly-interactive web site and dropping in great big globs of someone else’s Javascript is not going to solve all the problems; at a minimum, I’ve got to be able to read it, debug it and tune it for the client’s particular needs.

Did you know that a limited version of Safari, the O’Reilly online library, is included with a membership to the Association of Computing Machinery? I’ve been an ACM member for years and been meaning to get around to trying this out. My Javascript studies seemed the perfect occasion. I’m reading Shelley Power’s Learning Javascript online and getting quite a bit out of it. I love when you settle down with a book and start going “Oh, is that what that meant?” or “Now I get it!”

Eight attendees had a great time last night eating all of Janet’s brownies, cookies, cupcakes and Ray’s milk while discussing Python, news, questions, life, the universe and everything. The April meeting of the Python Special Interest Group of the Greater New Hampshire Linux User Group took place as usual on the fourth Thursday of the month at the Amoskeag Business Incubator in Manchester.

Shawn K. O’Shea took some great notes with links to dozens of the topics on his blog at: http://www.eth0.net/blog/?p=11 (what a cool domain, eh?)

Thanks to Bill and Alex for arranging the meeting, to Janet for the awesome confections, to Ray for bringing the milk, to the ABI for the great facilities and to all for attending and participating!

Over at the SANS Internet Storm Center, John Bambenek describes the increasingly grim situation for keeping machines secure. Automated patching triggers automated reverse engineering and the development of exploits in The Patch Window is Gone: Automated Patch-Based Exploit Generation. Deeply troubling.

Eleven people attended the April meeting of MerriLUG, the Merrimack Valley chapter of the Greater New Hampshire Linux User Group. Heather called the meeting to order at 7:30 PM, noted the that attendees were pretty much The Usual Suspects, and dispensed with the long-winded announcements for new members. http://www.gnhlug.org will tell you all you want to know.

Dan Walsh was the main presenter tonight. Dan had a very special visit from the Demo Gods, just before he was to start. His hard drive decided that his boot partition wasn’t. Never heard of ext3. Ouch. Ever the good showman, he borrowed my laptop, downloaded his presentations from the web, and put on a great show.

Dan mentioned that he’d lost his previous laptop during his recent tour in Europe when it was stolen and that maintaining your home directory encrypted was a Good Idea.

Dan reviewed the history of SELinux and the iterations we saw in Fedora 3 though 8 and RHEL 3 through 5 and what to expect in 9. He talked about the evolution of the policies, the different feature sets available, how the SELinux architecture can meet the stringent requirements of DoD level organizations (with bullet points like: “RHEL5: MSP Policy: EAL4+, LSPP, RBAC” - who wouldn’t be impressed?) to the Significant Others at home who really just want a machine to use the browser on.

Dan showed off the new kiosk policy, xguest, which was essentially a minimal-permissions user (no setuid, no executables in the home directory, no installation abilities, etc.) extended to run FireFox. Perfect when someone wants to borrow your machine for a second! In the default settings (installable in F8 or 9 with sudo yum install xguest), it creates a fairly ’safe’ user that can’t do a lot of harm and whose directories are temporary RAM-based and vanish when the user logs out. (You can modify it to keep a persistent home to store cookies and bookmarks.) Ideal for a library or public kiosk situations. Yes, the evil minded boys in the room could come up with some work-around exploits, but this is a promising start!

Thanks to Dan for a great presentation under trying circumstances, to Heather and Jim for managing and promoting the meetings, to Martha’s Exchange for providing the facilities, and to all who attended and participated.

UPDATE: Dan’s posted an article to Red Hat Magazine, “Confining the user with SELinux” that covers a lot of material in the presentation, with more detail than my notes and links for further study.

Eight people attended the April meeting of the Ruby Special Interest Group, http://www.nhruby.org, held as usual on the second Tuesday of the month in the meeting room at RMC Research.

We lead the night off with a brief video on Passenger from Phusion.nl, a new Apache module that host rails, like a mod_rails (not _ruby) module. Nick reported he’s been running it on one of his sites for a while and is pleased with the performance and the marked decrease in load. Having a mod_rails option available is likely to get hosting companies offering fractional horsepower shared virtual machines to be able to host Rails apps, bringing Rails onto the $7-a-month commodity hosting sites. Cool!

I asked for recommendations on the right way of parsing incoming XML and SOAP packets and was referred to Hpricot and soap4r. Another attendee asked for recommendations on Content Management Systems. Nick mentioned Radiant (which we got to see later in the presentation). comatose and railfrog. We got into a couple discussions during the evening on the stability and applicability of Ruby and Rails for many situations, citing high traffic web sites and the several runtime engines/VMs like JRuby in which Ruby code can run.

Finally, we arrived a the Live Hacking session where we got to watch Scott and then Nick show how to add new functionality to an existing app. Actually getting to see another craftsman at work brings out all sorts of good questions. Scott added chronic to his To-Do application. Chronic is a “natural language datetime parser,” according to the web site, and Scott showed how it could easily be integrated into an existing app, and accept values like “Next Tuesday” or “Thursday last week” and return sane datetime values. We also looked at what would be involved and set up a unit test to check our changes.

Nick showed us a little more of the Radiant application, and his work on making the Radiant CMS support multiple sites. The source he’s working on is stored at github.com, and the networking graph is a thing to behold. Nick spent a little time getting us familiar with the different philosophy of git (branching is inexpensive, merging is very smart, branches can interact in many ways including pushing to and pulling from each other) and then grabbed the most recent code and hopped right into to refactor a code snippet that was an inelegant hack using a deprecated technique into one that was more proper, running our unit tests before and after to confirm the refactoring didn’t break anything.

An excellent evening as usual! Thanks to all for their attendance and participation, to Scott and Nick for organizing, announcing and presenting, and to RMC Research for providing the nice facilities.

Sixteen people were present for the April Meeting of MonadLUG, the Monadnock Area Linux User Group meeting, held as usual on the second Thursday of the month at the School Administrative Unit #1 main office off Hancock Road in Peterborough.

As is usual with most LUG meetings, we spent the standard ten minutes wrestling with monitor settings for the cool new projector. We couldn’t do better than 640 x 480 so Guy was a trooper and persevered through the presentation at teeny resolution. Ouch. We’ll have to do some research to figure out how to get this new projector system to rock and roll.

Guy reminisced about his last presentation, (February last year) where he had talked about the new version of Joomla, which was due Real Soon Now and how he had promised to be back when it was released. In April of 2008, he was back to report that 1.5 is released, and the wait was worthwhile. In fact, version 1.5.2 is out now.

There was a discussion of the many new content management systems - Drupal is another one that’s received a lot of attention. Guy had also heard another one - ModX (http://modxcms.com/) that he hears all the cool kids are playing with.

Guy talked about how the web grew up in a table driven layout just to get positioning right, and that as css came along, that was prefered. Joomla templates are nearly always 100% CSS and valid HTML with few or no tables, and how there’s a lot of advantages from better accessibility, easier localization, better search engine optimization and fewer cavities.

As part of his presentation, Guy downloaded the .zip from the web site www.joomla.org, un-zipped the package, copied to an install directory, ran the installation (a pre-flight check, verified versions, etc.) and he was up and running (Joomla reminded to remove installation). Members noted that Guy showed them things about file management using the GNOME file manager that no one had bothered to try, since they would have all done it from a shell. Guy didn’t apologize for being a Windows refugee. There’s more than one way…

Guy talked about the first presentation of Joomla we saw, from Barrie North on 7 September 2006 at DLSLUG. Barrie has recently published a book, which Guy had with him and praised.

Guy gave us tour of the interface, both the public presentation and the administrative interface. Built-in default templates are pretty slick. The setup wizard was quite graceful. And addons and replacement templates seem to be available in huge quantities (Ted: downloading code off the internet and installing it to run on your computers without inspecting and understanding the code is a Bad Idea. Use only trustworthy sites and review what you get.)

Finally, Guy showed off a site he is developing for a client at Bristol Elder Care and talked about what was involved in getting the site up and running.

Thanks to Guy for a great presentation, to Charlie for organizing the meeting, to Ken and the SAU for the great facilities.