Andrew's blog (Entries tagged as software)

MythTV Status in your MOTD (and email) - Version 0.6.1

andrew@etc.gen.nz (Andrew Ruthven) — Thu, 13 Dec 2007 19:19:53 +0000

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.

Domain Name Registry System - version 1.47

andrew@etc.gen.nz (Andrew Ruthven) — Tue, 04 Dec 2007 01:15:17 +0000

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.

MythTV Status in your MOTD (and email) - Version 0.5.1

andrew@etc.gen.nz (Andrew Ruthven) — Thu, 22 Nov 2007 19:28:12 +0000

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.

MythTV Status in your MOTD

andrew@etc.gen.nz (Andrew Ruthven) — Thu, 15 Nov 2007 20:24:31 +0000

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.

IPv6 Firewalling

andrew@etc.gen.nz (Andrew Ruthven) — Wed, 14 Mar 2007 22:02:10 +0000

Firewalling IPv6 on Linux seems to be a vaguely documented topic, and most of that documentation seems to be out of date as it is a fast moving target. I've spent a bit of time over the last couple of days working on improving my firewalling situation and thought I should write up what I've found.

After a bit of digging I found that while IPv6 connection tracking was merged in 2.6.16, the configuration options are somewhat hidden. Up until yesterday I was running 2.6.19.x on my firewall and I discovered that while ip6tables allowed me to configure a stateful firewall, it wasn't actually doing anything!

I looked around for the required nf_conntrack_ipv6 module and couldn't find it. I looked in my running kernels config and couldn't find it. In fact I couldn't find any option for enabling IPv6 connection tracking at all. After some digging (grep'ing the Kconfig files helps) I found that I needed to change over to the new (experimental) Layer 3 Independent Connection tracking support.

The catch here is that if you have the old school Connection tracking (CONFIG_IP_NF_CONNTRACK) enabled you'll never see the new independent method (CONFIG_NF_CONNTRACK) in menuconfig. Which is why I'd never seen it before. So I disabled CONFIG_IP_NF_CONNTRACK (in IP: Netfilter Configuration), enabled (the now visible) CONFIG_NF_CONNTRACK (in Core Netfilter Configuration) went into both the IP and IPv6 Netfilter Configuration menus and selected support for the connection tracking option.

Compiled, installed and rebooted. Suddenly I had IPv6 connection tracking working. w00t! But no IPv4 NAT. Damn. It turns out that IPv4 NAT support was only ported to the new Layer 3 Independent Connection stuff in 2.6.20.

So I downloaded 2.6.20.3, jumped into the IP: Netfilter Configuration menu and found "Full NAT". That's what I want. Compiled, installed and rebooted.

Now I have my old IPv4 NAT working, and a full stateful IPv6 firewall (with no NAT!).

Oh, if you are using IPv6 stateful firewalling with Linux then you want to upgrade to 2.6.20.3, it fixes an issue with incorrectly classifying IPv6 fragments as ESTABLISHED and letting them through. Oops. Also, 2.6.20 moves the config options around again...

Pet Projects

andrew@etc.gen.nz (Andrew Ruthven) — Sun, 04 Mar 2007 23:05:42 +0000

It's kinda funny, I keep on finding little itches that I want to scratch, but never have the time to scratch them all. Before Susanne became pregnant I didn't have much time to scratch them. Now I have less time, and once the baby is born, well, practically none I expect.

I thought I would write down what some of them are on the hope it might focus me so I'll work on them in what spare time I have. Just some of the coding related itches I have are (not in any particular order):

Dashboard - I really want to get back into this
Really Simple CalDAV Store - Just generally get more involved with it.
Finish an Outlook 2000 calendar to CalDAV importer so Susanne's calendar can be available on the network (using RSCDS).
OpenSync - I'd like to have my Treo 650 sync nicely with Evolution and various LDAP phone directories. Also, once this is working perhaps Susanne can stop using Outlook (she only uses Outlook because it syncs with her Treo 650).
Revision control plugin for Tomboy - I use tomboy for note taking on my desktop at work, my desktop at home and a notebook. I use git for my .tomboy directory to keep the Tomboy directory in sync across my work desktop and the notebook. It'd be nice if tomboy automatically added new pages, and committed changed pages for me.
Improve tagging on the desktop - Leaftag is neat, but I'd like to have integrated support in the Save/Open Gnome dialog window, and have those tags shared amongst other users on my system & network.
mpd - I would like to integrate Avahi so I don't have to setup environment variables on new machines anymore. The other feature I'd like to add is a basic plugin handler.
Improve the integration between Asterisk and the Gnome desktop. There are some desktop apps for interacting with Asterisk out there, but they don't have the Gnome feel to them. I've had some ideas of different use cases and how they might be implemented. I'm going to generate some mock UIs soonish.

And then there is the ongoing tweaking of my MythTV setup, and all the other neat and nifty things I stumble upon and want to play with.

Leaving ICQ

andrew@etc.gen.nz (Andrew Ruthven) — Wed, 21 Feb 2007 00:10:38 +0000

Having just taken a closer look at the Acceptable Use Policy on ICQ as linked to from here I've decided to no longer use ICQ. When I first signed up with ICQ there weren't really many other options for IM. Actually, there probably weren't. Now other, better, options abound.

This decision probably won't affect too many people, I don't tend to use ICQ that much, but it affects a couple of folks I chat with.

Update: Add note about why I signed up with ICQ to start with.

Open source release of the Domain Name Registry System

andrew@etc.gen.nz (Andrew Ruthven) — Thu, 07 Dec 2006 21:07:48 +0000

After almost 3 years we (along with NZRS) have made another open source release of the software which runs the .nz domain name system. Head over to DNRS on SourceForge to check it out.

There is a slew of improvements from the previous release (as to be expected), so we hope that people will pick it up and get involved with it. Interestingly enough there were 800 downloads of the previous version (only 500 odd downloads of all the required components though).

Apple CalendarServer on Linux

andrew@etc.gen.nz (Andrew Ruthven) — Sun, 03 Sep 2006 03:54:49 +0000

Well, a bunch of people were quite interested in the news that Apple have released a CalDAV server under an open source license, myself included. It is available from the CalendarServer project webpage.

They state that they've only tested it under MacOS X. Which as I 've tried to compile it under Linux certainly shows!

I've managed to fight through the various bits and pieces and managed to get it to run! <phew>

Here are a few notes regarding my experience, some steps and packages might be missing. These are directly related to Debian Unstable.

Required Debian packages:

python2.4-dev
libkrb5-dev
attr (and make sure that partition is mounted with the option user_xattr, as mentioned in to the comments you can also run `mount -oremount,user_xattr <mount point>`)

You need to build the Python xattr package, by running (somewhere handy) the following. You may not need to actually checkout the code first. I had to do this as it wasn't automatically checked out for me. Of course, YMMV.



  svn checkout http://svn.red-bean.com/bob/xattr/trunk/ xattr

  <become root>

  cd xattr

  export C_INCLUDE_PATH=/usr/include/python2.4

  python setup.py install

The Python module plistlib.py to read MacOS X PList files is required, it is available from SVN. I copied it into /usr/local/lib/python2.4/site-packages on my machine and it was picked up.

Some of the packages which are checked out from SVN require some patches applied to them. The patches are:

Twisted
PyKerberos - Also the patches from trac might be useful. Don't worry about the includes one that is on trac, my supplied patch over rides that.

PyKerberos will need to be patched before it will compile, Twisted will compile but will do the wrong things with the extended attributes until is is patched. Then just re-running "run" from inside the CalendarServer directory should pick up the change.

I found the method that worked reasonably well was run "run -s" as provided by CalendarServer and whenever it broke (after checking out the required packages) apply the patch that I've provided, then run "run -s" again.

Update: Added details about plistlib.py and alternative to mounting the filesystem. Thanks Andrew M.
Update 2: Add fact that xattr wasn't automatically downloaded for me.
Update 3: The PyKerberos patch should now continue to work for MacOS X folks, and added details about the patches from Trac.