Matthew Revell

I’ve been playing with Python and Desktop Couch over the past few days, primarily as a learning exercise.

Why Desktop Couch? Well, there are a couple of reasons:

1. I’m writing a command-line podcast catcher and one of the main things that annoys me about other podcast catchers is that I end up downloading the same stuff if I move from one machine to another. CouchDB’s replication can solve that.
2. It seems more useful to learn to use Desktop Couch than to create my own file format to save my podcast catcher’s data.

What is Desktop Couch?

My understanding is that Desktop Couch is a project to make Apache’s CouchDB attractive to the developers of desktop applications, thereby giving those applications a common way of storing and replicating data.

Aq, one the people behind Desktop Couch, often gives the example of using a Couch database to store your web browser’s bookmarks. That way, if all your web browsers also speak to that database, you can share the bookmarks between them and, perhaps more interestingly, you can replicate your database to your other machines or the cloud and have your bookmarks on other computers, mobile devices, wherever.

Unlike SQL-based databases, CouchDB is not a relational database but a document-oriented database. A very simple relational database might have two tables:

• Table 1: first_name, last_name, favourite_colour
• Table 2: colour_name, rgb_hex_value, pantone_number

In table 1, favourite_colour would actually be a link to one of the entries in table 2.

In CouchDB, and other document-oriented databases such as Lotus Notes, you’d instead have a single document for each person that included all the info. So, no links elsewhere, just the info right there and then.

I’m no database expert but this is much simpler and, if you can get away with it, simple seems to be a good thing. I’ll leave it to other people to talk about why Desktop Couch, CouchDB and use of document-oriented databases are good ideas.

So, Desktop Couch provides a Python library that gives you access to Couch.

What I’m doing with Desktop Couch

I’m going to write here about my experience of writing a simple app that uses Desktop Couch. There’s not a great deal on the web, right now, about Desktop Couch so I’m hoping this will help me to work out what I’m doing and maybe provide a reference for others.

One thing to note, I’m pretty much learning Python at the same time and I’m not a developer, so I may write things that seem crazy or naive. Well, if I do, be kind

Flicking through the TV channels this morning I spotted a surprising message at the bottom of the screen:

Free Boston Celtics Ubuntu t-shirt

Turns out that their coach has been using the word “ubuntu” as an inspirational chant for his players and, following the team’s success, their fans have taken up the word too.

Not being a basketball follower, it looks like I’m a touch late to this. CNet has more.

I’ve been struggling to get a Remote Desktop connection from my Ubuntu laptop to Xubuntu running on my Viglen MPC-L.

foxmajik provides a simple solution on the Ubuntu Forums: ditch vino in favour of x11vnc. Works a treat

Each month, we in the Launchpad team make a new release.

Over the past couple of years, we’ve learnt some of what works — and what doesn’t — when announcing our releases. I thought I’d share some of that here.

Style and content

Keep it:

• Relevant: announce only what is of interest to the majority of your readers and what they can use “out of the box”. Direct your most ardent readers to the relevant milestone page in your bug tracker’ for the full details. Consider direct communication with those groups who are affected by a specific change. Ignore things that help you, the developer, rather than the reader.
• Personal: “The user” is not an abstract: they’re the person reading your text. Speak directly to them and show them how each change affects them. Use examples.
• Easily understood: don’t assume too much of your reader. Give them enough background to understand the problem you’re describing and your solution.
• Well ordered: start with the exciting, most relevant, stuff. Assume your reader has a limited attention span because, y’know, they do.
• Enticing: your readers are lazy and promiscuous. Suck them in by trailing the highlights in your headline.
  • Bad: ACME releases a RoadRunnerStop v1.2
  • Better: RoadRunnerStop 1.2: now easier to catch your lunch
  • Better: Catch more road runners with ACME RoadRunnerStop 1.2
• Benefit-led: tell your reader how you’ve fixed their life.
  • Good: Save time uploading branches to Launchpad
  • Not so good: Launchpad now supports Bazaar stacked branches
  • Bad: Launchpad will no longer OOPS when you attempt to alter a conjoined slave bug-task
• Plain-speaking: your readers aren’t stupid but you should err towards commonly used words and shorter sentences with fewer clauses.

Format

Launchpad release announcements have four parts, in order of importance:

• headline/subject line
• introduction
• detail of each change
• supplemental information: where to find more detail, other announcements, etc.

Examples

Take a look at the Launchpad releases page for some examples of our past release announcements.

I love a good logo. The best find the simplest way to communicate a brand’s values.

Take a look at our very own Ubuntu logo, for a great example.

It’s recognisable whether it’s tiny or huge, black and white or in colour. With just three curves and three circles, it conveys Ubuntu’s commitment to community, humanity and cooperation.

Now, we – the Launchpad team – have been wondering if there might be a better logo for Launchpad. Whether it’s another interpretation of the rocket ship or something entirely different, we’re holding a competition to see what ideas other people have.

So, here are the details:

Closing date: 31 March 2008
Rules and all that: https://help.launchpad.net/logo
Prize: one of the snazzy new Ubuntu messenger bags.

You can submit as many entries as you like, although the competition isn’t open to Canonical staff or vendors. The Launchpad team will choose the winner by majority vote. If you want to see our current rocket logo in situ, take a look at the Launchpad project page.

Any questions? Find me (mrevell) in #launchpad on Freenode, leave a comment or send us a mail to feedback AT launchpad.net.

One of the goals we have for Launchpad is to offer different ways to get data in and out.

For example, in addition to the web interface we have an email interface for the Bug Tracker. For many people, the quickest way to file a bug is to fire off an email. Of course, it also provides a full range of options for editing and commenting on existing bugs.

In Launchpad 1.1.12 we introduced bug feeds. Now, each bug, person, team, project and distribution in Launchpad has an associated Atom feed. I’ve used my bug feed on the home page of my website to give a flavour of what I’m working on. As I use Wordpress, which has built-in support for MagpieRSS, this was supremely easy.

Upgrade to the latest Wordpress

Before you begin, you should upgrade to the latest Wordpress. Previously, I was running 2.2.2 and it had some trouble with the Atom feed.

Pulling in the feed

First off, you need to pull in MagpieRSS, which is distributed with Wordpress.

I’ve created a sidebar specifically for the my site’s home page and I’ve got the following at the top of my home-sidebar.php template file:

<?
include_once(ABSPATH . WPINC . '/rss.php');
$myBugs = fetch_rss("http://feeds.launchpad.net/~matthew.revell/latest-bugs.atom");
$myBugsItems = array_slice($myBugs->items, 0, 4);
?>

The first line includes MagpieRSS and the next creates an array of the feed’s posts in $myBugs. I don’t have too much room in my side bar, so I use the last line to cut it down to the top four entries.

Displaying the feed

Actually displaying the feed is simple:

<ul>
<? foreach ($myBugsItems as $item ) {
	$title = $item[title];
	$url   = $item[link];
	echo "<li><a href=$url>$title</a></li>";
}

?>
</ul>

I’m looking to seeing how other people, in particular projects, use these new feeds.

Please post a comment or
contact me if you’re using Launchpad’s feeds or you have a suggestion for how we can improve them.

Update: two suggestions of easier ways to achieve the same effect. Dave Murphy suggested Wigitize.com (hat-tip Joey) and Jeremy Visser commented that Wordpress has a widget to embed a feed into your page.

Something I forget to put in the original post was that I’ve also used straight MagpieRSS (i.e. without Wordpress) to create an ugly but functional page at http://launchpad.understated.co.uk/. The code is pretty much exactly as shown in the Wordpress example above.

The past few days I’ve tried using my ThinkPad R50e with a wired connection to my Linksys WRT54GS (version 6). I’m running Ubuntu 7.10 (Gutsy).

Each time I plugged the Ethernet cable into the Thinkpad, Network Manager took far longer than usual to connect to the network. Once connected, I had no access outside my own network – i.e. no internet access – and even connecting to some machines on my network was hit and miss.

The fix: a firmware upgrade. My router was running 1.50.6 of the firmware. Under 1.50.9, everything’s fine and dandy. Visit the WRT54GS downloads page.

I have a Nokia 6233. It’s a 3G phone and is on Virgin Mobile UK. With the help of a USB<->Nokia cable (£3 from eBay), I’ve just used it to connect my Ubuntu laptop to the internet.

Following two threads on the Ubuntu Forums I managed to get connected with minimal fuss.

Here’s my /etc/wvdial.conf:

[Dialer nokia]
Init2 = ATZ
Init3 = ATE0V1&D2&C1S0=0+IFC=2,2
Init5 = AT+CGDCONT=1,"IP","goto.virginmobile.uk";
Modem Type = USB Modem
ISDN = 0
Phone = *99***1#
Modem = /dev/ttyACM0
Username = user
Dial Command = ATDT
Password = wap
Baud = 460800

After disabling networking via the Gnome network-manager applet, I opened a terminal and typed wvdial nokia. After some blurb, it reported my primary and secondary DNS servers and I was online.

I don’t recommend you use Virgin Mobile for data, though. At £5.12 per MB you’ll pretty soon be remortgaging. However, it has proven that I can get online with a phone as a modem using Ubuntu, so I’m now off to find a provider with a decent data tariff. 3 and T-Mobile look favourite so far, although everyone I speak to at 3 seems to have very little knowledge of using a phone as a modem.

Just a quick note: you can find blogs from many of the Bazaar guys now at Planet Bazaar.

Bloggers featured so far include: Aaron Bentley, Andrew Bennetts, John Arbash Meinel, Mark Shuttleworth, Martin Pool, Robert Collins and Szilveszter Farkas.

It’s not long now until Ubuntu Live! July 22 – 24 in Portland, Oregon.

Ubuntu Live will be a great opportunity to learn more about the technical and business background to both Canonical and Ubuntu and how Launchpad and Bazaar fit into that.

So, if you’re particularly interested in Launchpad and Bazaar, the sessions to look out for are:

• How Ubuntu uses Launchpad – Matt Zimmerman, Paul Alexander
• An introduction to Launchpad for collaboration and hosting – John Meinel
• Tutorial: Collaboration and code hosting with Launchpad and Bazaar – John Meinel

It probably goes without saying that the Ubuntu project is the largest user of Launchpad. Hearing Matt and Paul’s tale of how Ubuntu uses Launchpad will give you a practical understanding of what makes Launchpad unique.

John Meinel’s talk will be a great way to see how Launchpad and Bazaar – together – can work for your project. In John’s tutorial session, he’ll then show exactly how Launchpad and Bazaar work together, with plenty of opportunity for attendees to learn the ins and outs.

Now’s a good time to book, if you’re thinking of going, as you can get a fat discount with the super-special-Canonical-discount-code Enter the code ubu07ucm to get a 35% discount.