Mercurial for the Homeless

Generally, I'm not one to talk about crazy dreams. You know those ones right before you wake up that seem like a Salvador Dali painting? Anyway, I had one the other day where either I was homeless living out of a car, or I was observing someone like that. Anyway, it dawned on me in the dream that Mercurial (or any DVCS) would be perfect for that situation because I figured that the homeless person would only have intermittent network connectivity, but he still needed to get work done.
OK, maybe the part about someone living out of their car "needing" to get coding done is a bit crazy, but I already admitted that it was a weird dream. I suppose jet-setting open-source gurus might feel kinda homeless from time to time, and they do need to make use of their time on planes, so maybe it wasn't so crazy after all. And, when you get right down to it, the two use cases are more similar than different, and Mercurial and other DVCSs excel at it.
For the record, the rest of the dream was related to work I'm doing for a client converting from CVS to SVN without necessarily having shell access to the server machines. I thought of a zillion ways where I could do something trivially in Mercurial but SVN (without shell access) just kept kicking my butt. I just hope shell access comes through, so the dreams can cease.

Charles.

Problem with Hudson as a Windows Service

Setting up Hudson to run as a windows service is wicked easy. However, at a client we ran into a problem with the user that the service runs as. By default, the service runs as the Local Service (or maybe Local System) user. Also, by default Hudson runs out of the .hudson directory under the user's home directory (in Documents and Settings).

This ran fine until someone logged into the console. Hint number one that there was a problem was that Windows took forever to log the user in while there was a huge amount of disk activity. Then, suddenly Hudson reverted to its state from several weeks before - recently added users and builds were missing. Looking around I could see that many users had a .hudson directory (as well as Maven .m2 directories), which made no sense - only the Local Service user was running Hudson.

As near as I could tell, logging in on the console was somehow changing the value of the Local Service user's home directory. And for some reason, Windows thought everyone should have a .hudson directory. (Thus the long time to login - Windows was copying the Hudson directory to the new user.)

Anyway, the solution was to create a real directory for Hudson - C:\Hudson, and to point Hudson at that by setting the HUDSON_HOME environment variable. To make this as easy as possible, I just set it via the Control Panel as a system-wide environment variable. I filled the directory with the contents of the .hudson directory in my home, as it seemed to have most/all of the recent users and jobs.

Also, while fixing all of this up, I created a limited (non-administrator) user to run the service. This is just good security that was skipped when Hudson was initially set-up (by someone else) as a quick proof-of-concept prototype.

enjoy,
Charles.

Book: The Principles of Successful Freelancing

The Principles of Successful Freelancing by Miles Burke
ISBN 978-0-98004552-4-6

The Principles of Successful Freelancing is a comprehensive introduction (if that's not a contradiction of terms) to striking out on your own as a freelancer. This book is perfect for someone who is considering moving to freelancing or possibly for someone just starting out.

Mr. Burke covers all of the basic areas of starting and running a freelance business. He discusses how to set up your business and your office, how to sell your services, how to manage your money, and how to give good customer service, which is ultimately the most important aspect of a personal freelancing business. He also addresses how to balance work and life beyond work, which is hard in general and specifically hard in a one-man shop. He concludes with something I haven't seen in a "start you own business" book - where to go next. Do you want to remain as a one-man shop, do you want to grow into a "real" business, or do you just want to "retreat" to the old 9-to-5 job? I don't recall a book like this consider the option of going back to the grind.

Each chapter concludes with two "case studies" - Emily and Jacob. These two characters represent two very different people who might want to go into freelancing. The studies at the end of each chapter explain how these personality types might react to the issues and challenges discussed in the chapter. This device helps the reader envision how he or she might deal with the issues discussed.

Early on, I got the mistaken impression that this book was a bit fluffy. The typography has a fair amount of white space, and it looks kinda arty rather than serious and dense. (OK, I grew up with punched cards and line printers. When's Matlock on?) But, by the time I finished the book, as I looked back across it, I really couldn't think of anything that wasn't covered. Sure, there are whole MBAs built around marketing, and this book only has one chapter on it, but the Mr. Burke provides a perfectly reasonable introduction to the subject. I think I got this "fluffy" mis-impression because immediately prior to reading Successful Freelancing I read Eric Sink's The Business of Software, which is very detailed about a few aspects specifically related to running a small software business. Successful Freelancing covers a wider range of topics, and it is not aimed specifically at software freelancers. If anything, it's aimed more at web designers who probably like nicer typography.

To conclude, The Principles of Successful Freelancing is a great first introduction to the idea of freelancing. It covers all the bases to help someone evaluate whether or not to go into business for himself.

enjoy,
Charles.

Choosing Java Versions on Mac OS X

While debugging another manifestation of the "wrong library for groovy webtest" bug recently, I found an email thread that makes reference the java_home command (sadly, I can't find an online manual page to link to) to cleanly select a specific version of the JVM under OS X. Here I thought manually pawing through /System/Library/Frameworks to look for versions to set JAVA_HOME to was the "right" way to do it. Learn something new every day.

enjoy,
Charles.

Dealing with DreamHost Server Migration

DreamHost sent me an email telling me that my account had been moved to another server. OK, fine - "what's that mean to me, Al Franken?" They said that it shouldn't affect most sites, but that you'd have to look out for paths in your applications that look like "/home/.something/username".
So, when when on my clients emailed me to say that his WordPress site was giving him an error message that read:

Unable to create directory /home/.spuds/user/domain.com/wp-content/uploads/2009/07. Is its parent directory writable by the server?

I knew that I had been bitten by this error. OK, how to fix it? I grep'ed the WP PHP files, but couldn't find a path like that. So where was it coming from?

On a hunch, I decided to look at the wp_options table in the WP database and found a row called upload_path, and sure enough, it contained the offending directory. I just removed the ".spuds" portion of the path, as per DH's directions, and it all worked.

So, if you're on DreamHost, and they moved your WordPress blog, and it suddenly stopped working with that error message, try looking through wp_options in your databse. (FYI, DH puts a random string between the wp and the options to prevent collisions with other users in the same database.)

enjoy,
Charles.

Aliens have taken control of my PowerPoint!

I just cut-and-pasted some text from a PDF into PowerPoint, and this is how it rendered:



The aliens are the bullet points from the source PDF. WTF?

Little Summary of the Open Source Bridge Conference

It's been about a week since the Open Source Bridge Conference, and here are some brief thoughts about it. I'd summarize it by saying that it's approximately 80% as good as OSCON for nearly one tenth the cost, and it was here in Portland.

Of course, it was smaller than OSCON - a lot smaller. But it had a lot of what I go to OSCON for - talks about cool open-source software. There weren't as many talks, not as many projects, not as many "rock stars", but it's the same basic idea. The exhibitors area made a Soviet-era consumer electronics show look like NES. I felt sorry for them.

As I hinted at, the price (something like $250 for non-early bird) was beyond reasonable - it's cheap, in a good way. At the moment, I'm between clients, so there's no way I could afford over $1000 for OSCON. If I had that kind of money this year, I probably would have blown it on the Java Posse Roundup - maybe next year.

Finally, having it in Portland was crucial for me, especially this year. However, I realized a down side to that: since I'm basically local, at the end of the day, I didn't hang around for social events or the hackers lounge, but I rather went out with friends whom I was staying with in the area. So the fact that it's local sort of limited my participation.

Anyway, it was a great version 1.0, and I look forward to going to OSB again next year. Oh yeah, props out to O'Reilly for being a sponsor of a "competing" conference. That was cool.


Charles.

Version control: Autopia vs. off-roading

When I was a kid, it was cool to go to Disneyland and ride the Autopia ride. For those of you unfamiliar with it, you get to "drive" a car along a track. As I recall, you get a gas pedal, and the steering worked for about plus-or-minus a foot off the center-line of the track. It is a far cry from driving a real go-cart let alone a real car on the highway or going off-roading (not that I've ever intentionally been off-roading.) Comparing traditional centralized version control systems to distributed version control systems is a bit like autopia vs. off-roading.

With a centralized version control system (VCS), your options are limited, and to a certain extent that can be a good thing. A critical difference between Autopia and a centralized VCS, is that the VCS actually goes somewhere - your code line continues to move forward and doesn't loop back to the starting point.

A distributed VCS (DVCS) can follow the exact same path that a cetralized VCS provides/requires - just like you could drive a 4x4 along the Autopia track. With a DVCS tool like Mercurial, you can implement policies that end up following the same trajectory as you would with Subversion. You have one "master" repository; everyone checks out from it; everyone commits directly to the central repo; the only branching is officially sanctioned, and it occurs in master repo. And that's fine for a lot of applications. Also, some organizations want to operate on the straight and narrow, which is fine if it works for them.

As I mentioned before, I think Mercurial is very simple to use on that path. But, the blessing or curse or fun or power of a DVCS is that you need not follow that track. You can go off the track. Doing so might be the fastest way to get where you're going. Or, you might end up in the weeds. And, you can drive back onto the main road. Developers can head off in some strange direction in their private repo, share their changes with other repos, bring in changes from other repos, abandon their work, or merge it all back into the designated "main" repo. All the while, they have a real VCS tracking their work and saving it - not just random hacking in a random directory.

If Autopia is where you want to be, more power to you. I wouldn't recommend using a DVCS in that environment. Although I don't go seriously "off-road" in my development, I like to have the option to get a little mud on the tires. And even if I'm "driving on the track" and using Mercurial like a centralized VCS, I like to clone a tree onto my laptop to operate disconnected for an extended period, which is something that's not generally possible with traditional VCSs.

My most "extreme" use of Mercurial to-date has been to mirror a P4 repository that I only have intermittent access to. Hg lets me do all my work without having to get the admin to let me onto the P4 repo from by dyanamic IP address. Before that, I would work for weeks without checking in, which makes me nervous. Due to some ignorance and poor planning, I created a bit of a mess in my hg development repo, but I was able straighten it all out, build a series of mq patches, stage them on another repo, and push them back to the P4 tree.

404 Errors with Django flatpages

In a Python class I'm teaching, I had the students do the Django tutorial with some added bits. One of the added bits was to add an About page using Django flatpages. A couple of students had problems where they were getting 404 errors even though there was a flat page defined at the /about/ URL.

I had one student zip up his project (including his sqlite database) and send it to me. (One of the other "added bits" was that they had to create portable projects - no hardcoded paths in settings.py.) When I first ran his project, sure enough - 404. I poked around, and everything looked good. Then, I used manage.py loaddata to load my data (including a flat page) into his DB, and it all worked fine. So, it was a data issue, not a project-level mis-configuration.

After reading a comment from another student about this problem, I looked into the database using SQLite Manager, where I could see that the flat page was assigned with site_id #3, not the default #1, and somewhere along the line he had created multiple sites in his DB. I looked in settings.py, and sure enough, SITE_ID referred to site #1, not #3 As noted in the flat pages docs, this needs to match (under some circumstance). Changing that, fixed it all up with the students original data.

If you have been having this problem, I am hopeful that the Google sent you here, and you can see how to fix it.

enjoy,
Charles.

How to Get a Software Job w/o Experience.

This is a talk I gave at WOU last week. I also presented it later the same week at Beaver Bar Camp. In an ideal world, I would have delivered the talk at least a few weeks before the deadline for Google Summer of Code applications. :-( OTOH, maybe some students will join some F/OSS projects this summer, and they can nail the application next year.

How to Get a Software Job w/o Experience

View more presentations from Charles Anderson.

Slideshare liked it (but I'm not sure what their criteria are): "Your presentation How to Get a Software Job w/o Experience is currently being showcased on the 'Career' page by our editorial team."

enjoy,
Charles.