Author Archive | Ted Roche

Notes from Python SIG, 22-Jan-2009

By Ted Roche on January 26, 2009 in Home Page

The twenty-second of the month was the fourth Thursday, the usual night for the Python Special Interest Group to meet at the Amoskeag Business Incubator in Manchester, New Hampshire. Thirteen attendees made it to the January meeting, making PySIG one of the more popular regional/topical meetings of the Greater New Hampshire Linux User Group.

As usual, coordinator Bill Sconce had a printed agenda with lots of news to go over. We had a round of introductions, though it was mostly a gathering of the regulars. We talked about Gotchas! — those little surprises that pop up while working through the day — and “reverse-gotchas!” — the ah-ha moments that bring enlightenment.

Kent Johnson presented his regular Kent’s Korner presentation on context managers and the ‘with’ statement. Kent’s notes for this and all past Kent’s Korners can be found on his web site. The with statement, along with decorators and generators (see how the KK sessions build upon each other!) can make a very powerful and very pythonic addition to writing Python code.

Arc Riley made the main presentation, on writing extensions in C. Arc was apparently one of the very first programmers to actually attempt to build an extension from scratch in Python 3.0, as he found that some of the key documentation was missing and some of the most important declaration about structures can only be found by reading the source code of Python itself. Arc documented his adventures for us, found a bug report to the Python folks, and provided the group with a very useful document of where the gotchas are, and some very useful bookmarks. The last link includes Arc’s notes as well as the C and Python code for the sample extension.

Thanks to Arc and Kent for great presentations, to Janet for the cookies and Ray for bringing the milk. Thanks, as always to Bill for running the meetings and to all for attending and participating!

Ideas worth repeating

By Ted Roche on January 26, 2009 in Personal, Security

“We reject as false the choice between our safety and our ideals.”

President Barack Obama, 20 Jan 2009

“They who would give up an essential liberty for temporary security, deserve neither liberty or security.”

Benjamin Franklin, 1775

Notes from NH Ruby Group, 15-Jan-2009: Jonathan Linowes

By Ted Roche on January 18, 2009 in JavaScript, OpenSource, Ruby, Web Development

Jonathan Linowes was kind enough to drive from “the other side of the Notch” all the way down to the seacoast to present to the New Hampshire Ruby Group on the 15th of January (note that the NH Ruby group has moved their regularly scheduled meetings to the third Thursday of the month). Fourteen members attended the meeting, which started with a round of introductions. Pizza, soda and T-shirts were provided courtesy of EngineYard — thanks!

A typical scene at a Linux user group meeting for the first ten minutes of a meeting to be consumed with the speaker struggling to get his X windows display to sync up with the projector. I’m beginning to suspect that the Ruby group equivalent is for the speaker to discover he’s packed the wrong DVI-mini-DVI-HDMI-Video-VGA adapter and no one else has the right video adaptor for his MacBook despite a half-dozen machines present. I wonder if Apple made a mistake by changing this adaptor in every model.
ReviewRamp is Jonathan’s project – a SaaS web site for a group to bring in documents, route them through their own defined process, and approve/disapprove/select documents. Jonathan offered examples such as business plan reviews, marketing plans and job applications. Designed to look as much like a desktop application as possible, ReviewRamp has a simple GUI, with templates and wizards to make it a couple of clicks to process. Under the hood, Jonathan talked about the architecture, which includes RESTful protocols, and a design intended to scale to thousands of projects, hundreds of submissions and a handful of reviewers per project. Unlike many JavaScript-only sites, RevewRamp works well with JavaScript disabled; sweetened with JavaScript enabled. ReviewRamp is publicly in beta. Jonathan presented some slides of the models: reviewers, projects, pages, subpages, fieldsets. This last was a segue into the 3rd presentation: fields are generated via metadata for each project, but the database tables don’t change for each project, so each project has virtual tables vis Jonathan’s DynamicTable design.

Next, Jonathan had a presentation on “Cucumber: How I Slice It” Jonathan had worked PHP and other languages before, was very attracted by Ruby as a new language and the philosophy of testing, testing and more testing. Unit-testing, test-driven-design, behaviour-driven-design. Jonathan also pointed us to Brandon Keepers presentation as an excellent starting point.

Jonathan showed us some of his Cucumber scripts, which include a lot of pretty cool extensions to the base, like {show me} to actually end a test by launching a browser so he could visually verify a result. It was apparent that Jonathan really took to the testing regime, adding extensions like “He” or “She” instead of always including “The current logged in user” or “the current project”

Should you use RSpec or Cucumber? Both, according to Jonathan: each has strengths and weaknesses. RSpec is more tuned to unit-test individual functions where Cucumber is more tuned to describing behavior and outcomes.
Check out

cap deploy:features

to run Cucumber on the deployed app (typically, you’d do this on a staging server, not a production server)
Shows some example Cucumber scripts. They describe in English the point of the test, and use keywords (“GIVEN” “WHEN” “{actorname}”), an action and an expected result. This is actually parsable Ruby code that defines fixtures and features and processes defined within the story runner. It’s not just a requirement, it’s actually the test as well!

Finally, running out of time, Jonathan jumped into his DynamicRecord presentation, where he had developed a method that was ActiveRecord compatible so that it could be integrated in the rest of a standard rails app, but actually queried against virtual tables that were created on the fly rather than actual tables on disk. Interesting stuff, and I’m looking forward to seeing this code pushed into OpenSource, Jonathan’s eventual goal.

Thanks to Jonathan for the great presentations, to Nick for running the presentation, to Tim for hosting the facilities and attempting to webcast the presentation, to Engine Yard for the pizza and T-shirts, and to all the members who made it to the meeting!

You can download the 3 presentations from the NHRuby site here: ReviewRamp, Cucumber, DynamicRecord, or view them online (Flash/JavaScript required) here.

GNHLUG in 2008, a retrospective by the numbers

By Ted Roche on January 5, 2009 in Home Page

I’ve added a link to the GNHLUG PastEvents page that provides a comma-separated file listing all the events from calendar year 2008. Some interesting highlights:

Despite under-counting or -reporting of many events, we recorded attendance of 589 people, total, at GNHLUG events. This looks to be down a bit from last year, but I know I didn’t post as many numbers as last year. And it’s almost the same as 2006. Worth watching.
The best attended event of the year (30) was the GNHLUG cookout. Thanks to Bruce Dawson and Carole Soule for hosting the event!
Tied for second (at 22) were:
- MerriLUG’s Linux Digital Audio Workstation presentation by Christoph Doerbeck,
- DLSLUG’s presentation by Bill Stearns on FUSE, and
- Kent Johnson‘s Python 101 presentation at MerriLUG
The bronze medal goes to Máirín Duffy’s Photographic Prowess (MerriLUG ,20)
Honorable Mentions:
- Ben Scott’s Linux Server that Could (CentraLUG, 19),
- Arc Riley’s PySoy (PySIG, 17),
- James Fogg’s Administrator in a Box (DLSLUG, 17),
- Guy Pardoe’s Joomla 1.5 (MonadLUG, 16)
- And another tie: Richard Weait’s OpenStreetMap (MerriLUG, 15), Ed Lawson’s Scribus DTP (CentraLUG, 15) and my Cascading Style Sheets (DLSLUG, 15)

In terms of cumulative attendance, MerriLUG was on top as usual:

MerriLUG (140)
CentraLUG (83)
PySIG (80)
DLSLUG (65)
MonadLUG (57)
RubySIG (48)
SLUG (46)

This is certainly a measuring issue, too: I record CentraLUG’s numbers every time, but many groups only infrequently post their numbers. Finally, by average attendance, a few numbers change, pointing out the many unreported ??? posted to the web page, and also reflected the varied numbers of times each group met:

DLSLUG: 16.25
MerriLUG: 14
PySIG: 10
SLUG: 7.67
MonadLUG: 7.13
CentraLUG: 6.92
RubySIG: 5.33

If anyone would like to work with the data, you’ll find the CSV linked here (below the heading for each year, a link labeled “CSV format”) or linked directly off the bottom of individual year’s pages: 2008, 2007, 2006, 2005. And if anyone is really into it, I’ve got an OpenOffice.org spreadsheet I’d be glad to share.

Notes from Python Special Interest Group, 17-December-2008

By Ted Roche on December 18, 2008 in LAMP, Python, Web Development

Six folks attended the December meeting of the Python Special Interest Group, held on the irregular third Wednesday in December to allow for the festivities next week. (We normally meet the fourth Thursday, same place, same time.)

There wasn’t a formal agenda, and discussion was first the ice storms of last week and everyone’s power status.

I talked with Bill about setting up my new Sansa player with Rockbox and using gPodder in Fedora10 to sync music. The gPodder Podcast client can sync with using the standard file-based method or by using the Media Transfer Protocol popular in many players. To run with gPodder, I needed to install libMTP and PyMTP (there’s a Python connection!) I also discovered while importing RSS feeds that there’s a bug in Fedora 10’s version of Mark Pilgrim’s awesome feedparser, fairly easy to patch, documented here. It’s an arguable bug; it may be that feedparser throws an error instead of behaving more gracefully when hander RSS that might not be fully valid, in this case apparently a bad Unicode character. Perhaps not fully following Postel’s Law, paraphrased “be conservative in what you do and liberal in what you accept.” Is ignoring malformed Unicode too liberal? A philosophical question, perhaps. I noted that the RSS feed that fails in gPodder and from the Python command line actually passes the http://feedvalidator.org tests. Hmm.

Arc had sent a link, “If Languages were Religions,” which included the suggestion, “Python would be Humanism: It’s simple, unrestrictive, and all you need to follow it is common sense. Many of the followers claim to feel relieved from all the burden imposed by other languages, and that they have rediscovered the joy of programming. There are some who say that it is a form of pseudo-code. ” Read the whole post; there are some good ones!

Bill Freeman had an idea he’d like to float for a project to avoid name contention issues, using a naming scheme similar to Java’s com.sun…. namespace for individual projects. Kent dug around in the comp.lang.python archives for some previous threads on the subject to review what had been said on the issue before.

Kent wanted to talk about Python 3.0! Shawn had sent a link to the list for Python porting resources, but wasn’t able to make the meeting. We discussed some of the issues with porting 2.x Python code to Python 3.0 and tested out the 2to3 program. Arc and Matt arrived and joined in the conversation. We first converted the canonical “hello world” program and worked up to Bill’s telephone list program, Arc suggested jinja, and an unpublished project that Kent had been working on involving recognizing human languages, each of which had gradually more and more complex issues. The 2to3 program won’t always make working code, but it does a fine first pass in making all of the well-known changes in converting a 2.x program to 3.0. In running the programs through 2to3 and examining the results, the group had a good discussion about some of the syntax and structural changes in 3.0

Thanks to Bill Sconce for organizing the meeting and bringing the milk, to Janet for the wonderful airplane cookies, to the Amoskeag Business Incubator for providing us with the great facilities and to all for attending and participating.

Rails Launch Checklist

By Ted Roche on December 17, 2008 in Home Page

Robby on Rails posts a thoughtful “Launching Ruby on Rails projects, a checklist,” a handy list of things to be thinking of from day one in a project.

Notes from CentraLUG: 1-Dec-2008

By Ted Roche on December 14, 2008 in Home Page

Five members attended the December meeting of the Central New Hampshire Linux User Group, one chapter of the Greater New Hampshire Linux User Group, held as usual on the New Hampshire Technical Institute Library Room 146. (Note that there will not be a January meeting at NHTI, as the facility will be on break.)

A good time was had by all. We discussed and demonstrated the new Fedora 10, released on 25-November. Attendees were impressed with the depth and breadth of the Network Manager, version 0.7.0. We reviewed the dialogs with configuration for wireless, wired, broadband mobile (cell), DSL and VPN configurations. Bill Sconce did some Googling and reported that Network Manager, the application, was available for several other desktop managers, including his favorite, Fluxbox.

We also admired the updated “Monitor Resolution Settings” available off the System|Preferences|Hardware|Screen Resolution GNOME menu. In combination with the latest X.org, the interface gave us the ability to detect the projector and adjust the laptop’s screen display and arrange the geometry of the two outputs, either mirroring them or placing them side-by-side or top-to-bottom. Very slick!

We talked about the ease of upgrade: I had Fedora 9 installed on this laptop and used the Fedora-supplied “preupgrade” package to stage the laptop and perform the upgrade very easily. A restart into the new kernel and confirmation that the /etc/fedora-release version was correct, and I was upgraded! I have never seen an easier upgrade in a RedHat-family-based system.

We discussed the challenges in digging up solutions to more complex troubleshooting problems, not Fedora 10 related. Mark talked about a problem it took him months to track down that eventually pointed to remarking out a single module in rc.d. Dave referred us to A.P. Lawrence.com where he was able to come up with the magical incantation to correct the timezone settings on an SCO box.

Meanwhile, back at Fedora 10, we looked at the new OpenOffice.org 3.0 and talked about some of the compelling features in the new version. The ability to edit PDF files was something that generated a lot of interest. Bill pointed out that there is no concept of text flow within a PDF, so while you can correct a typo, you can’t expect the text to be reflowed.

There were questions on OO.o compatibility with other office packages, like MSOffice and WordPerfect. Novell has come out with a translator to read Office-BASIC macros and translate them into OpenOffice.org’s StarBASIC. Version 3.0 can apparently read the new proprietary Office DOCX documents. We talked about where to find good resources for OpenOffice.org (suggestions welcomed!). Bill mentioned that Jim Kuzdrall’s presentation on OpenOffice.org styles (see Sept 20, 2007 for links to notes and slides) was a real help in him getting OpenOffice.org working. We also mentioned that Solveig Haugland’s blog was a great resource for more information.

Thanks to Bill Sconce for bringing the projector, to all for participating and to the New Hampshire Technical Library for the great facilities. Note that there is no January meeting planned at the moment, but keep an eye out for a February announcement.

Wrestling GenuineJava onto Fedora 10

By Ted Roche on December 9, 2008 in Home Page

In order to get access to a client’s VPN, I needed to get their VPN client software installed on my Fedora 10 workstation. Following their basic directions, it was apparent that there was an attempt to run Java in FireFox, and it was failing. Running FireFox from a shell, I could see IcedTea errors. So, I went off for instructions to get Sun’s Java installed.

There were some clues from the http://ubuntuforums.org/showpost.php?p=1356952, and few promising Google results. The Fedora Project had an FAQ on Java that was a good start. That pointed to http://www.city-fan.org/tips/JpackageJava with some fairly intricate instructions to download the Sun JDK package and invoke some serious RPM magic on it to turn it into a set of RPM packages that could be installed on Fedora. Once I followed the instructions, the ‘alternatives’ script showed me that Java was installed – hurrah! I tried the VPN install again, but no joy, same IcedTea error messages. Hmm. It turned out that the global Mozilla FireFox plugins, stored in /usr/lib/mozilla/plugins, had two shortcuts: libjavaplugin_oji.so and libjavaplugin.so. Running FireFox and examining about:config and searching for plugin told me that Moz should only be using the first one, but that was pointing to the correct place. The second, on the other hand, was pointing to the Iced Tea installation. FireFox’s about:plugins showed me that Iced Tea was still the preferred plugin. I deleted the second, libjavaplugin.so, link and tried it one more time. Yes! Installed. Whew!

Now to get to work…

Notes from October Python SIG: Unit testing and Sphinx

By Ted Roche on December 9, 2008 in LAMP, OpenSource, Python, Technology

An even dozen (or maybe an odd dozen…) folks attended the October Python Special Interest Group meeting, held as usual on the fourth Thursday of the month at the Amoskeag Business Incubator.

It was a busy and exciting meeting. Vigorous conversations filled the first half hour, as we welcomed a few new members, a few members not seen in a long time, caught up on news and what’s new in the Python world, and made a round of introductions.

Kent S. Johnson presented a new episode of Kent’s Korner, talking about the unit testing facilities available in Python. Python has a couple of options, including a xUnit-clone version and a more Python system in nose. We got into a great discussion on the philosophy of unit-tests, the test-first-fail-code-test cycle, test-driven development, and so forth. It was quite enlightening.

Arc Riley made the second presentation on the Sphinx documentation generator for Python. Arc talked about the history of Python documentation, with docstrings and EPyDoc and ReStructuredText (not to be confused with ReST, Representational State Transfer!). Sphinx seems to be a popular project name these days, as I heard about a different project by the same codename both at the RubySIG and maintainer Patrick Galbraith’s presentation at MonadLUG).

Arc provided us with the slides to his presentation, available on the gnhlug site here.

Links and notes from this meeting and past meetings can be found at Shawn O’Shea’s blog at http://eth0.net/ — thanks, Shawn!

NOTE that the next meeting of PySIG will take place on Wednesday December 17th at the Amoskeag Business Incubator across the hall from our usual meeting room. Hope to see you there!

Thanks to Arc and Kent for great presentations, to Bill and Alex for organizing and running the meetings, to Janet for the incredible cookies, to the Amoskeag Business Incubator for the great facilities, and to all who attended and participated.

SFTP, DropBear on Linksys WRTSL54GS and OpenWrt

By Ted Roche on December 4, 2008 in Home Page

For some reason, I couldn’t get this to work the first time through, but perseverance paid off. On our home office LAN, we use the LinkSys WRTSL54GS router. The WRTSL54GS (whew!) is the Storage Link (that means it has a USB connection) version with 802.11 G technology, the standard 54 Mbps wireless protocols, with the SpeedBoost option.

I’ve upgraded the factory-installed firmware with the third-party Open Source firmware OpenWrt. This gives me more capabilities, the ability to tweak lots of settings, and the ability to add on many, many third party applications. You might not think of a little sub-$100 consumer-grade router as a platform for third-party applications, but under the hood this device is a Linux box with a decent CPU, a bit of spare RAM, switches, routers, bridges and USB connections. Thanks to the storage option, you might make your router a file server using Samba or NFS protocols, or an ftp or SFTP server you can use to share files inside the firewall or securely outside of your firewall (if your contract with your upstream provider allows you to run servers; many consumer connections disallow this, unfairly, in my opinion.)

OpenWrt is accessible remotely through telnet (discouraged, as it is not secure), Secure Shell (ssh), and a web interface. There are even third party add-ons to created an enhanced web interface (WebIf2) with a built-in package manager, usage graphs that update live, and more.

This week’s project was to get the storage working. I was under a misunderstanding that disk sharing had been broken in the version of OpenWrt (White Russian) that I’m using, but a CentraLUG meeting earlier this year, presenter Bruce Dawson showed off one of his LinkSys machines with disk storage working, so I was encouraged to give it another try. Following the instructions at the OpenWrt wiki for USBStorage and SFTP, I was up and running pretty quickly. Nifty!

This is pretty cool. In slightly less geeky terms, this gives me the ability to transfer files to our home office LAN from anywhere on the Internet without having to keep any of the machines in the office running, just the router itself and a USB flash drive hanging off it.

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