catalyst - 2

Back in the days when the Unix world was more trusting, we had a command called finger. This command was used to find out information about a user. The output would look something like this:

Login: andrew         			Name: Andrew Ruthven

Directory: /home/andrew             	Shell: /bin/bash

On since Wed Jun 25 09:18 (NZST) on pts/0 from chimaera.etc.gen.nz

   1 second idle

Plan:

This is my .plan!  Surprise, surpise, surpise!

And if you ran finger against a host it would return a list of the users logged in. But the finger daemon that was queried had a few issues. Early versions had gaping security holes, and as more bad guys started appearing it became a useful way to find out what accounts existed on a host. This was useful to know who to target.

Because of these reasons the use of finger has declined, quite drastically.

One thing of interest though is the "Plan" section, this displays whatever is in the .plan file in the users home directory. This used to be used to indicate what someone was up to, or their plan.

Last year some of the folks at Catalyst started creating themselves Wiki pages called .plan or ToDo in their own namespace. In a moment of insanity I decided to create a finger daemon that would return those wiki pages. I also hooked it up to our internal staff directory. So it would return something like:

Name : Andrew Ruthven                         Extn: 7231

Email: andrew.ruthven@catalyst.net.nz         DDI : +64 4 xxx yyyyy

Nick : puck                                   Cell: +64 27 xxx yyyyy



Plan:

                              Andrew Ruthven/.plan



                                   Priorities



Do more work.

This was easy to do with our original wiki software - MoinMoin - because it had an output mode for plain text. But we've changed to MediaWiki, and Mediawiki doesn't have support for spitting out pages in plain text.

Yesterday I decided enough was enough and wrote a filter to support this. It grabs the Printable version of the page and strips out the toolboxes and headers and footers, then passes it to the text based web browser links before printing out the plain text version.

Perfect.

If you are interested in this filter, you can grab it from its git repo or you can just grab the script from here.

It seems that the iLiad might be really nice eBook reader. It supports PDF, allows you to annotate documents using a touchscreen and lots of other fancy things.

Nice.

Now if only it cost less than AUD$1,000...

I'm pleased to announce a new version of my little script - 0.6.1.

Notable new features:

• Details on disk space are reported, and individual storage groups[0];
• If there isn't enough program guide data, a warning is shown;
• The --email-only-on-conflict option has been extended to mean "Only on alert" which now includes both the previous points (this means, you'll only be emailled if there is something which needs your attention);
• For each recording (scheduled, current and conflict) show the channel name it is related to;
• We do a little bit of rinsing on the XML data now to remove some invalid unicode characters that occasionally appear;
• Suppress some warnings if the user doesn't have access to MySQL and handle some other error conditions in a nicer manner.

If you install the .deb, then the MOTD is updated automatically and the email will be sent daily if there are conflicts (and you've set some email addresses).

As usual, you can check the project page.

[0] To get the details on the individual storage groups you need to apply a couple of patches to MythTV. Please see the FAQ in the tarball or for Debian type boxes, /usr/share/doc/mythtv-status/FAQ .

Update: I've disabled comments for now as I'm tired of all the spam.

It is time for another open source release of the Domain Name Registry System (DNRS) - the software which runs the .nz domain name space.

Head over to DNRS on SourceForge to check it out.

I'm pleased to announce a new version of my little script - 0.5 0.5.1.

Notable new features (from the shiny new ChangeLog):

• Add support for printing colour in the encoder status display.
• Show any schedule conflicts, or if the MythTV Perl API isn't usable, a warning is displayed.
• Display the amount of time until the next recording.
• Add --version & --help options.
• Allow suppressing blocks of output.
• The report can be sent via email with the subject set correctly. With an option to only send out email if schedule conflicts are detected.

If you install the .deb, then the MOTD is updated automatically and the email will be sent daily if there are conflicts (and you've set some email addresses).

As usual, you can check the project page.

Update: I've released 0.5.1 which should make the colour look good on non-black backgrounds as well.

The other day I was recompiling some kernels during the day on our MythTV backend, which at the time happened to be recording my wifes favourite program (Grey's Anatomy, we discovered it part way through the season, so the repeats are good). It turns out the compilation caused some issues with the recording (which reduced the WAF).

So to increase the WAF, I'm making sure this doesn't happen again. I've written a script that spits out the MythTV status which is then displayed in the MOTD. It is available over here.

I've found this is a pretty effective way of letting me know of any upcoming recordings and what is going to be happening on the system in the next little while. It is a whole lot easier than using the status page on MythWeb.

Sample output:

MythTV status for localhost
===========================
Status: Mon Oct 15 2007, 8:41 AM

Encoders:
cerberus (9) - Idle
cerberus (12) - Idle

Scheduled Recordings:
2007-10-15 13:30:00 - Grey's Anatomy
2007-10-15 18:00:00 - 3 News
2007-10-15 20:30:00 - Mythbusters
2007-10-15 22:00:00 - Flight Of The Conchords
2007-10-16 13:30:00 - Grey's Anatomy
2007-10-16 18:00:00 - 3 News

I run Debian, so there is a .deb. For those not running Debian there is a tarball (but the MOTD updating glue is Debian specific at the moment). For those interested in hacking there is a git repository.

Hopefully I'm not the only one that finds this useful.

A fantastic song from the RIPE 55 Meeting.

I'll try the embedded thing as well...

It is great to see that the OLPC folks have been listening to the clamouring on the net about wanting to buy a OLPC.

The concept they've come up with is pretty cool. Give 1 Get 1 is basically, pay OLPC US$399 (it doesn't say US, but I'm guessing here) and they'll ship a laptop off to a kid somewhere in a developing country, and they'll also ship a laptop to your kid (it is for your kid right?).

It is still a bit steep for me, but still a pretty cool idea.

During the week I stumbled across a great write up of an awesome looking place called TechShop. Which is a fully featured work shop where you can buy day passes, monthlies or annual membership. If you haven't heard of this place, go and read the write up.

We so need one of these in Wellington. I've occasionally been tempted to sign up to a woodworking night course just so I can use the workshop.

A few of us at Catalyst had a little chat about what would be involved. Currently the list is:

1. Find a suitable warehouse
2. something
3. Profit

Step 2 needs some work...

What do you do if the back of your stereo cabinet is a mess and you've been a network monkey in the past?

Simple, you grab some cable management brackets from your good junk pile[1], some bits of MDF and you hack your stereo cabinet.

I think it came out much tidier, and now I can safely push it back without risking damaging cables!

If you're wondering why some of the power cords aren't plugged in, they belong to devices we don't use very much, why have them plugged in and drawing power if we aren't actually using them?

[1] "Good junk pile" every geek should have one, it is that collection of odds and sods that you don't really need, but which - just might, one day - come in handy. It should be noted however that they don't tend to have a very high Wife Approval Factor.

There is another computer recycling event happening at the Wellington Stadium.
I don't know much about it, but here is the contents of the email I received about it:

Not sure what to do with the old computer in your garage? Or the old mobile phones cluttering your drawers? How about free disposal in an environmentally sustainable way?

The Computer Access NZ Trust (CANZ) is organising eDay 2007, a free community computer recycling day for households, small businesses and schools on Saturday 29 September at the Westpac Stadium car park from 9am-3pm. This follows on from the very successful Dell Free Recycling Day held in September 2006.

The average New Zealand household has more than one computer, representing a total of over seven million electronic devices. Their eventual disposal represents a potential challenge to our environment. eDay 2007 is part of a nationwide effort by communities and industry to start to address the electronic waste problem.

Bring in your old computer equipment on 29 September - there is no charge. All computers will be broken down and the parts will be recycled for other purposes. Mobile phones will also be disposed of in an environmentally sustainable way.

Vehicle access for the Westpac Stadium car park is off Waterloo Quay. CANZ is organising the day in partnership with the Wellington 2020 Communications Trust, Remarkit, the Wellington City Council and a number of industry sponsors.

Only computer equipment and mobile phones will be accepted so please do not bring other electronic equipment. If you have any queries about the event, please contact Mike Ennis (partsplus@actrix.gen.nz).

We normally see quite a few people finding this blog via Google. It can be quite amusing to see what search terms led to us.

Earlier this month I decided to check it out again, there were no hits from Google. At all. This was kinda odd, as the googlebots (both for the search engine and for reader) normally hit us quite often.

Looking back through the logs the last time Google hit us was the 14th of March. Which is quite some time ago.

I cruised over to Google and checked Reader, and sure enough the most recent article from our blog is dated the 14th of March. I then tried telling Google to index blog.etc.gen.nz using the WebMaster tools. No dice, it says:

General HTTP error: Domain name not found

Two things happened on that day:

1. I moved from DynDNS to FreeDNS,
   
2. I added AAAA (IPv6) records to some of my hosts, which is why I moved to FreeDNS. DynDNS doesn't support that.
   

It appears that one of those changes caused Google to start ignoring us. And in fact, it is the change to FreeDNS.

Damn.

I think it is finally time to bite the bullet and start running my own nameserver. Which I want to do anyhow to start using DNSSEC...

Some further investigations with the help of a mate (you know who you are) I've discovered that FreeDNS is rejecting DNS queries from Google. I'm not the only one to have encountered this problem.

Update: The issue is FreeDNS. Updated entry to reflect that.
Update 2: Okay, the FreeDNS maintainer is now allowing Google to access our DNS entries again, so we're back in Google. But still, bizarre.

Due to popular request I'm hiding the majority of the geeky blog entries from the front page of our blog. Anything that is only in the Catalyst category won't be shown on the front page, you'll need to click through to that category to see the geeky Catalyst related things.

I'll need to update a few of the blog aggregaters to handle this change...

In our house we have a server that does a number of tasks, one of which is playing a jukebox (using MusicPD) it is hooked up to an amp that has speakers in our study and in our family room. This rocks, turn on the amp, have continuous music that we want to listen to and no chatter.

Unfortunately this doesn't extend to the lounge. Which means that if you sit in the lounge you can only just hear the music (unless you turn it up too loud). I've thought off and on (mostly off) about extending the jukebox to the lounge, the other week Susanne asked about having this, which meant it was finally time for me to really look into possible solutions.

Warning, geeky bits follow...

Since we used to use Icecast2 to stream the jukebox to Susanne's computer in our old flat I tried that first. We have a PC in the lounge that is a MythTV frontend that we could play the stream on, so that aspect is covered. Unfortunately the 5 second lag which was acceptable when Susanne's computer was a long way away from the main jukebox in our old flat was too annoying when the speakers were only a room apart (yes, I could have reduced the buffers, but it would never have been quite right).

So fall back to plan B, stick another soundcard in the jukebox computer and run line level audio to the amp in the lounge. We managed to dig up an old soundcard in the good junk pile (every geek should have a good junk pile), stuck it in the computer and then proceeded to try and configure ALSA to drive it. The plan was to duplicate the same audio stream out to both soundcards. After a bit of researching and a bit of tinkering with asound.conf and it not working I decided not to waste any more time on that path.

I vaguely recalled that PulseAudio was incredibly flexible and allowed all sorts of things. A quick apt-get install pulseaudio pulseaudio-module-hal and bit of reading, and I found that adding the following line to /etc/pulse/default.pa:

load-module module-combine master=<sound card 1> slaves=<sound card 2> set-default-sink combined

Would create a new virtual soundcard output (PulseAudio refers to this as a sink) called "combined" that would replicate the audio to both soundcards. Awesome. (The master and slaves settings were determed by using paman to inspect the PulseAudio devices.)

Then after recompiling MusicPD (to add PulseAudio support, the version in Debian unstable already has it, but stable doesn't), telling it to use that sink and voila, both soundcards are playing the jukebox.

To actually get the line level audio to the lounge I've used some Cat5 we already have running there (with suitable audio flyleads) and we have the jukebox playing in the lounge, in sync with the family room. The sound quality is pretty good, so I won't worry about balanced audio or anything else fancy like that. Gotta love structured cabling.

Another benefit of PulseAudio is we will be able to configure our Linux workstations to use the jukebox soundcards as audio sinks as well, which will mean no more tinny little monitor speakers. w00t!

Update: Say which file to add the load-module line to, and fix a typo.

Why doesn't hardware have changelogs?

Perhaps I've been using open source software for too long, but I like to scan through the changelogs (a log of changes that the authors have made before releasing a new version) to see what has changed. This can give me hints to new features to checkout, or changed behaviour that it would be helpful to know about.

But hardware (and closed source software) typically don't have changelogs. An example is my Brand New Replaced Under Warranty D-Link DGS-1008D. The old one was hardware revision C3. The new one is C4. What has changed? Will it not brick itself like the old one did after a years usage? Is this one going to be faster because they've improved the code or silicon in some fashion?

I'll never know...