The next August 16th, Debian will turn 20.
What are you planning to do to to celebrate?
Being a DIY geek, I decided to create some craft projects dedicated to the Universal Operating System. I'll publish them, one per week, on this blog with a detailed tutorial, released under a CC:BY-SA 3.0 license. If you have an original project dedicated to Debian (from cookies and cakes to knitted socks, from beaded earrings to handpainted mugs, from plushies to pottery, from glass arts to lettering and so on) join me!
Post a tutorial about your project on your blog (or if you don't have one, send me a mail and you'll publish it here as guest post) with the hashtag #debcraft and a free (as in freedom) license. Bonus points for project using recycled material :). Ready to start? Below my first one: swirl charms from plastic bottles.

---

This is a little tutorial on how to create swirl charms for keyrings from plastic bottles.
The project is really easy and quick to realize, the materials very common and the result quite pretty.
I found out that there are tons of tutorial in the Internet about how to make jewelry from PET bottles, and I'll surely give them a try (earrings, in particular, seem a good idea).
If you want some inspiration, I suggest you to check out the amazing work of Turkish artist Gulnur Ozdaglar who creates ethereal jewelry and everyday objects from plastic bottles.

"What is PET bottle?
A domesticated bottle kept for companionship or amusement."
Gulnur Ozdaglar

What you will need

• one or more plastic bottles
• metal keyring
• jump rings (I made my own ones with metal wire from a spiral block note)
• red nail polish, or acrylic paint (only for the painted swirl)
• red thread and needle (only for the transparent with red embroidery)
• scissors
• a lighter
• pen and paper (if you want to use a paper swirl as guide while cutting)
• a pin (to punch holes)
• pliers and cutters

In the pic there's also a soda can, because I thought it could be a good material too.
After some tests, I decided that soda cans would probably need some resin to make the edges less sharp and avoid cuts, so I think I'll experiment a bit more with them. Step 1 First of all, you'll need to cut out the swirl from the bottle.
I cut it in the upper part of the bottle, using a paper swirl as guide to cut the swirl shape as regular as I could. Step 2 As the edges of the cut are a bit raw, I decided to lightly melt them with the lighter: be careful as if the plastic melt too much it will ruin our nice swirl. Also, remember to open a window while doing it: it's not a lot of melting but better safe than sorry. Step 3 With a pin or a needle punch a hole in the upper part of the swirl, where the jumpring will be set to connect the swirl with the keychain ring. Now you need to decide which type of swirl do: for the painted one, follow step 4a; for the transparent one with the red embroidery, follow step 4b. Step 4a Paint your swirl red, or of your favourite colour (I experimented a bit here, having lots of nail polish, and made also a purple one). Step 4b With a pin or a needle, punch a series of holes, in the middle of the swirl, following the swirl shape.
Then embroider it using backstitch. Step 5 Add the jumpring, if you have a ready made one.
If not, use a pair of cutters to cut a little bit of metal wire and the pliers to create a ring with it, insert in the hole and close it. Step 6 Connect the jumpring and the metal keyring. Congratulations: you now have a swirl shaped keycharm!

This week was all about getting mount into shape, addind umount and hacking up a prototype for the mtab issue. With all my patches to mount the boot log looks like this:

INIT: version 2.88 booting
Using makefile-style concurrent boot in runlevel S.
Activating swap...done.
Checking root file system...fsck from util-linux 2.20.1
hd2 : tray open or drive not ready
hd2 : tray open or drive not ready
hd2 : tray open or drive not ready
hd2 : tray open or drive not ready
end_request: I/O error, dev 02:00, sector 0
ext2fs_check_if_mount: Can't check if filesystem is mounted due to missing mtab file while determining whether /dev/hd0s1 is mounted.
/dev/hd0s1: clean, 44101/181056 files, 283413/723200 blocks
done.
Cleaning up temporary files... /tmp.
/etc/rcS.d/S06mtab.sh: 48: /etc/rcS.d/S06mtab.sh: cannot open /proc/mounts: No such file
Activating lvm and md swap...(default pager): Already paging to partition hd0s5!
done.
Checking file systems...fsck from util-linux 2.20.1
hd2 : tray open or drive not ready
hd2 : tray open or drive not ready
end_request: I/O error, dev 02:00, sector 0
done.
Mounting local filesystems...done.
Activating swapfile swap...(default pager): Already paging to partition hd0s5!
done.
df: Warning: cannot read table of mounted file systems: No such file or directory
Cleaning up temporary files....
Configuring network interfaces...inetutils-ifconfig: invalid arguments
ifup: failed to open pid file /run/network/ifup-/dev/eth0.pid: No such file or directory
Internet Systems Consortium DHCP Client 4.2.2
Copyright 2004-2011 Internet Systems Consortium.
All rights reserved.
For info, please visit https://www.isc.org/software/dhcp/
can't create /var/lib/dhcp/dhclient./dev/eth0.leases: No such file or directory
Listening on Socket//dev/eth0
Sending on   Socket//dev/eth0
DHCPDISCOVER on /dev/eth0 to 255.255.255.255 port 67 interval 7
DHCPREQUEST on /dev/eth0 to 255.255.255.255 port 67
DHCPOFFER from 10.0.2.2
DHCPACK from 10.0.2.2
can't create /var/lib/dhcp/dhclient./dev/eth0.leases: No such file or directory
bound to 10.0.2.15 -- renewal in 42107 seconds.
done.
Cleaning up temporary files....
Setting up X socket directories... /tmp/.X11-unix /tmp/.ICE-unix.
INIT: Entering runlevel: 2
Using makefile-style concurrent boot in runlevel 2.
Starting enhanced syslogd: rsyslogd.
Starting deferred execution scheduler: atd.
Starting periodic command scheduler: cron.
Starting system message bus: dbusFailed to set socket option"/var/run/dbus/system_bus_socket": Protocol not available.
Starting OpenBSD Secure Shell server: sshd.
GNU 0.3 (debian) (console)
login:

As you can see, mountall.sh works fine now (it's the line about mounting local filesystems). This is a list of issues I tackled this week:

• Hurds mount lacks some command line flags:
  • -O, --test-opts
  • -t, --types: semantic difference to what Linux' and FreeBSDs mount does.
• Hurds mount -t auto does not work.
  • needed for fstab entries with fstype=auto
  • needed for d-i
• The hurd package does not provide an umount helper, needed for d-i.
  • also needed for umountfs, umountnfs.sh
  • required arguments -f, -v, -r, -d
• Patch series for all the issues above posted: http://lists.gnu.org/archive/html/bug-hurd/2013-07/msg00031.html
• Hurds swapon/swapoff lacks some command line flags:
  • -v, --verbose: set if VERBOSE=yes is given in /etc/default/rcS.
  • Patch posted: http://lists.gnu.org/archive/html/bug-hurd/2013-07/msg00055.html

Note that even though I've implemented umount, it doesn't actually work yet. That is because umount needs a mtab file or /proc/mounts to do anything, because you can either invoke umount with the mount point or the device and umount needs an mtab style file to figure out whether the argument is referring to the former or the latter. So the next big issue is the mtab issue. There is some information about that in the Hurd wiki, it even is a gsoc project idea of its own: http://www.gnu.org/software/hurd/community/gsoc/project_ideas/mtab.html But I need this now, this cannot wait for another gsoc. The implementation outlined by that page consists roughly of:

• In every translator, keep a list of translators (active and passive) being bound to nodes of the translator. Think of this as keeping a list of child-translators.
• Add a RPC procedure to query this list.
• Creating a mtab-translator that recursively queries translators starting from a given translator and collects all the information required for an mtab file.

If this hypothetical mtab translator is bound to say /proc/mounts this would solve all our problems:

% settrans -ca /proc/mounts /hurd/mtab /

As this involves adding a RPC procedure and keeping a list of passive and active translators, this involves some design decisions. As discussed in #hurd I hacked up a prototype and post it for review: http://lists.gnu.org/archive/html/bug-hurd/2013-07/msg00022.html As soon as I get the necessary feedback on this issue, I will get the implementation up to speed. Until then, I will pick another item from my status list, most probably the ifupdown issue. Speaking of feedback, all of my patches I sent last week were merged at the appropriate locations. That was really quick, many thanks for that :) While working on the mount issues, I frequently looked at the implementation of Linux' and FreeBSD's mount to see how --types is handled there. I must admit that I was not to keen about the idea of writing c again, but I was positively surprised by the code I've seen from Hurd so far. As Hurd is the operating system of the GNU system, its code is free to use any GNU extension to libc and gcc including nice stuff like nested functions. If you look at the different mount implementations, you'll find the Hurd version to be the most modern and clean one imho:

Linux

http://sources.debian.net/src/util-linux/2.20.1-5.4/mount/mount.c

FreeBSD

http://sources.debian.net/src/freebsd-utils/9.0%2Bds1-11/sbin/mount/mount.c

Hurd

http://sources.debian.net/src/hurd/20130620-1/utils/mount.c

See you next week :)

virsh send-key guestname KEY_LEFTALT KEY_SYSRQ KEY_H This doesn t work in virt-manager, but the virsh CLI tool is just fine. PS: zerofree rocks! And can be installed in Grml 2011.05 just finely.

Half a year ago, I reported that I had to find a replacement for my trusty old Thinkpad X41. Unfortunately I did not have much time to spend on it, and it took a while to find a model I believe will do the job, but two days ago the replacement finally arrived. I ended up picking a Thinkpad X230 with SSD disk (NZDAJMN). I first test installed Debian Edu Wheezy as a roaming workstation, and it seemed to work flawlessly. But my second installation with encrypted disk was not as successful. More on that below. I had a hard time trying to track down a good laptop, as my most important requirements (robust and with a good keyboard) are never listed in the feature list. But I did get good help from the search feature at Prisjakt, which allowed me to limit the list of interesting laptops based on my other requirements. A bit surprising that SSD disk are not disks according to that search interface, so I had to drop specifying the number of disks from my search parameters. I also asked around among friends to get their impression on keyboards and robustness. So the new laptop arrived, and it is quite a lot wider than the X41. I am not quite convinced about the keyboard, as it is significantly wider than my old keyboard, and I have to stretch my hand a lot more to reach the edges. But the key response is fairly good and the individual key shape is fairly easy to handle, so I hope I will get used to it. My old X40 was starting to fail, and I really needed a new laptop now. :) Turning off the touch pad was simple. All it took was a quick visit to the BIOS during boot it disable it. But there is a fatal problem with the laptop. The 180 GB SSD disk lock up during load. And this happen when installing Debian Wheezy with encrypted disk, while the disk is being filled with random data. I also tested to install Ubuntu Raring, and it happen there too if I reenable the code to fill the disk with random data (it is disabled by default in Ubuntu). And the bug with is already known. It was reported to Debian as BTS report #691427 2012-10-25 (journal commit I/O error on brand-new Thinkpad T430s ext4 on lvm on SSD). It is also reported to the Linux kernel developers as Kernel bugzilla report #51861 2012-12-20 (Intel SSD 520 stops working under load (SSDSC2BW180A3L in Lenovo ThinkPad T430s)). It is also reported on the Lenovo forums, both for T430 2012-11-10 and for X230 03-20-2013. The problem do not only affect installation. The reports state that the disk lock up during use if many writes are done on the disk, so it is much no use to work around the installation problem and end up with a computer that can lock up at any moment. There is even a small C program available that will lock up the hard drive after running a few minutes by writing to a file. I've contacted my supplier and asked how to handle this, and after contacting PCHELP Norway (request 01D1FDP) which handle support requests for Lenovo, his first suggestion was to upgrade the disk firmware. Unfortunately there is no newer firmware available from Lenovo, as my disk already have the most recent one (version LF1i). I hope to hear more from him today and hope the problem can be fixed. :)

Not so much ago, we had a boom of new enterprises offering Massive Online Open Courses (MOOCs for short). First were Thrun and Norvig (Artificial Intelligence), with Widom (Introduction to Databases) and Ng (Machine Learning). Then, these initial experiments led to the creation of Udacity (founded by Thrun) and Coursera (founded by Ng and Koller). I have been keeping an eye on them for some time and, in fact, I have been contributing to a project similar to youtube-dl (which I package for Debian), but focused on downloading videos from Cousera, called coursera-dl. I started contributing to coursera-dl because I wanted to stratch some itches with downloading with aria2c, but soon the original author of the project granted me write permission to the repository and I have been one of the persons that commits the most, which is strange, since I was not the original creator of the program. So far, from the courses that grant certificates, I have concluded the following:

• Algorithms: Design and Analysis, Part 1 (Coursera)
• Machine Learning (Coursera)
• Introduction to Databases (Coursera)
• Quantum Mechanics and Quantum Computation (Coursera)
• Introduction to Cryptography I (Coursera)
• M101P: MongoDB for Developers (10gen)
• M102: MongoDB for DBAs (10gen)
• M101J: MongoDB for Java Developers (10gen)

I have to say that this have been a pleasant experience, with some of the courses being challenging, but not up to what an undergraduate course would be (and the fears of some people that such courses would threaten the conventional University-style model are a bit far at this point). Anyway, talking about challenging courses, in particular, prof. Umesh Vazirani's "Quantum Mechanics and Quantum Computation" had a lot of (computational) work and this was one of the courses that prompted me to use a computer algebra system for manipulating some tedious calculations. In particular, I used a mix of the online SAGE math server and Wolfram Alpha, whichever I found the syntax to be easier to use for the problem in question. It is with happiness that I see that there are efforts to get SAGE again packaged in Debian. Another (positively) surprising course has been Dan Boneh's "Introduction to Cryptography I", which was more theoretical and more serious than what I was expecting. It even included some nice proof sketches and discussion of recent results. The last course on cryptography that I took was in 1998 and a lot of things changed since then, including the way to think about cryptography. But more on that on a future post. There are some other courses that I may be completing soon and that I will post more about, with some reviews of the good and the bad parts of select ones.

Half a lifetime ago, somewhere at the end of the last millennia I became a free software enthusiast. On and off, I've been working on Free Software for the past fifteen years - most of them unknown, discontinued by now; a huge part of this work was a hobby: small, infrequent contributions. But it was, and still is, something I enjoy doing, something that satisfies my hunger for knowledge, my desire to give back to the community I received so much from. Over the years, what originally started as a desire became a need. What started as a preference, became a requirement. And all through these years, I had a dream, a clear goal I wanted to achieve, which gave purpose to a lot of things I wrote and worked on.This past Monday, the goal was reached. I left the BalaBit support department this week, and went for greener pastures, to do what I wanted to do since I became a free software fanatic: work on free software for a living. As of July first, I'm officially a syslog-ng OSE developer, working full time on 100% Free Software. And not just any software, but something used by millions all over the world. For the first time in my life, I am able to do what I want, for a living.So how did I end up here?It all started on a boring night in December, 2010, when I wrote the first version of the mongodb destination, which also marks my entrance into the syslog-ng contributor scene (apart from a set of bugfixes I was doing in my role as a software engineer at support). From this grew an agreement between the support and development departments (and myself, of course), that I can spend 20% of my time working on syslog-ng OSE. For a while, I spent my Fridays doing just that, eventually obtaining another hat: maintaining the 3.3 stable branch, and later the 3.4 branch too. Meanwhile, the 20% percent was reconsidered, and became 50%, with the premise that it will become 100% in the not too distant future. That future is now.That future is now, and while there will be a slower ramp-up time, there are great things in store, of which, I'll talk about in a later post. Needless to say, though, even if I achieved a dream, there are other desires to pursue, and I'm not going to spend fifteen years achieving them: it's time to fire up the rocket boots, and see where they take me.Two years. Watch this place.

A month ago, a mail hit the OpenStack mailing list entitled "The OpenStack Community Welcomes Developers in All Programming Languages". You may know that OpenStack is essentially built using Python, and therefore it is the reference language for the client libraries implementations. As a Lisp and OpenStack practitioner, I used this excuse to build a challenge for myself: let's prove this point by bringing Lisp into OpenStack! Welcome cl-openstack-client, the OpenStack client library for Common Lisp! The project is hosted on the classic OpenStack infrastructure for third party project, StackForge. It provides the continuous integration system based on Jenkins and the Gerrit infrastructure used to review contributions. How the tests works OpenStack projects ran a fabulous contribution workflow, which I already talked about, based on tools like Gerrit and Jenkins. OpenStack Python projects are used to run tox, to build a virtual environment and run test inside. We don't have such thing in Common Lisp as far as I know, so I had to build it myself. Fortunately, using Quicklisp, the fabulous equivalent of Python's PyPI, it has been a breeze to set this up. cl-openstack-client just includes a basic shell script that does the following:

• Download quicklisp.lisp
• Run a Lisp program to install the dependencies using Quicklisp
• Run a Lisp program running the test suite using FiveAM, that exit with 0 or 1 based on the tests results.

I just run the test using SBCL, though adding more compiler on the table would be a really good plan in the future, and should be straightforward. You can admire a log from a successful test run done when I proposed a patch via Gerrit, to check what it looks like. Implementation status For the curious, here's an example of how it works:
Unfortunately, the implementation is far from being complete. It only implements for now the Keystone token retrieval. I've actually started this project to build an already working starting point. With this, future potential contributors will be able to spend efforts on writing code, and not on setting up the basic continuous integration system or module infrastructure. If you wish to help me and contribute, just follow the OpenStack Gerrit workflow howto or feel free to come by me and ask any question (I'm hanging out on #lisp on Freenode too). See you soon, hopping to bring more Lisp into OpenStack!

Okay, so imagine this: you just generated an SSH RSA key and threw its public part on system B into ~foo/.ssh/authorized_keys and its private part on system A into ~bar/.ssh/id_rsa but can t login. Why? Automated processes (Jenkins *cough*) often need you to ssh(1) manually once, to accept the remote host s server key. Do that. The id_rsa file on system A must be owned by the user bar and chmod 0600 or 0400 (similarily, the .ssh directory has strict permission checks, and everything in the path until there). Check those. And, the most surprising one of the day: if there s an id_rsa.pub it will be used for offering a key to the remote host (B) even if it does not match the secret key. Deleting A:~bar/.ssh/id_rsa.pub apparently makes OpenSSH generate the public part from the secret key each time (or just put the correct pubkey there), but if one s there, it seems to like to use them. (That was the only part of this post that was news to even me, of course ) And, as bottom line: hello to Planet Debian from mirabilos at work , too. I ll occasionally tag posts so they show up here, if I think they re of interest, since I m doing Debian work at the dayjob, too.

A month ago, a mail hit the OpenStack mailing list entitled "The OpenStack Community Welcomes Developers in All Programming Languages". You may know that OpenStack is essentially built using Python, and therefore it is the reference language for the client libraries implementations. As a Lisp and OpenStack practitioner, I used this excuse to build a challenge for myself: let's prove this point by bringing Lisp into OpenStack! Welcome cl-openstack-client, the OpenStack client library for Common Lisp! The project is hosted on the classic OpenStack infrastructure for third party project, StackForge. It provides the continuous integration system based on Jenkins and the Gerrit infrastructure used to review contributions. How the tests works OpenStack projects ran a fabulous contribution workflow, which I already talked about, based on tools like Gerrit and Jenkins. OpenStack Python projects are used to run tox, to build a virtual environment and run test inside. We don't have such thing in Common Lisp as far as I know, so I had to build it myself. Fortunately, using Quicklisp, the fabulous equivalent of Python's PyPI, it has been a breeze to set this up. cl-openstack-client just includes a basic shell script that does the following:

• Download quicklisp.lisp
• Run a Lisp program to install the dependencies using Quicklisp
• Run a Lisp program running the test suite using FiveAM, that exit with 0 or 1 based on the tests results.

I just run the test using SBCL, though adding more compiler on the table would be a really good plan in the future, and should be straightforward. You can admire a log from a successful test run done when I proposed a patch via Gerrit, to check what it looks like. Implementation status For the curious, here's an example of how it works:
Unfortunately, the implementation is far from being complete. It only implements for now the Keystone token retrieval. I've actually started this project to build an already working starting point. With this, future potential contributors will be able to spend efforts on writing code, and not on setting up the basic continuous integration system or module infrastructure. If you wish to help me and contribute, just follow the OpenStack Gerrit workflow howto or feel free to come by me and ask any question (I'm hanging out on #lisp on Freenode too). See you soon, hopping to bring more Lisp into OpenStack!

Half a year ago, I reported that I had to find a replacement for my trusty old Thinkpad X41. Unfortunately I did not have much time to spend on it, but today the replacement finally arrived. I ended up picking a Thinkpad X230 with SSD disk (NZDAJMN). I first test installed Debian Edu Wheezy as a roaming workstation, and it worked flawlessly. As I write this, it is installing what I hope will be a more final installation, with a encrypted hard drive to ensure any dope head stealing it end up with an expencive door stop. I had a hard time trying to track down a good laptop, as my most important requirements (robust and with a good keyboard) are never listed in the feature list. But I did get good help from the search feature at <ahref>Prisjakt, which allowed me to limit the list of interesting laptops based on my other requirements. A bit surprising that SSD disk are not disks, so I had to drop number of disks from my search parameters. I am not quite convinced about the keyboard, as it is significantly wider than my old keyboard, and I have to stretch my hand a lot more to reach the edges. But the key response is fairly good and the individual key shape is fairly easy to handle, so I hope I will get used to it. My old X40 was starting to fail, and I really needed a new laptop now. :) I look forward to figuring out how to turn off the touch pad.

Recent Intel-based systems often implement something called Intel Rapid Start Technology. Like many things with the word "Technology" in the name, there's a large part of this that's marketing. The relatively small amount of technical documentation available implies that it's tied to your motherboard chipset and CPU, but as far as I can tell it's entirely implemented in firmware and could work just as well on, say, a Cyrix on a circa 1996 SIS-based motherboard if someone wrote the BIOS code[1]. But since nobody has, we're stuck with the vendors who've met Intel's requirements and licensed the code.

The concept of IRST is pretty simple. There's a firmware mechanism for setting a sleep timeout. If you suspend your computer and this timeout expires, it'll resume. However, instead of handing control back to the OS, the firmware just copies the entire contents of RAM to a special partition and turns the computer off. Next time you hit the power button, the firmware dumps the partition contents back into RAM and resumes as if nothing had changed. This takes a few seconds longer than resume from S3 but is far faster than resume from hibernation since it starts the moment the system gets power.

At a more technical level, it's a little more complicated. The first thing to know about this feature is that it's entirely invisible unless your hard drive is set up correctly. There needs to be a partition that's at least the size of your system's physical RAM. For GPT systems, this needs to have a type GUID of D3BFE2DE-3DAF-11DF-BA-40-E3A556D89593. For MBR systems, you need a partition type of 0x84[2]. If the firmware doesn't find an appropriate partition then the OS will get no indication that the firmware supports it. Boo.

(The second thing is that it seems like it really does have to be on an SSD, and if you try to do this on spinning media your firmware will ignore it anyway)

If all the prerequisites are in place, an ACPI device with an HID of INT3392 will exist. It has four methods associated with it: GFFS, SFFS, GFTV and SFTV. GFFS returns an integer representing the events that will cause the system to wake up from S3 and suspend to SSD. The system will wake after the timeout expires if bit 0 is set, and will wake when the battery becomes critically low if bit 1 is set. The other bits appear to be unused at the moment[3]. SFFS sets the wakeup events, using the same bit values as GFFS. GFTV returns an integer containing the current wakeup timeout in minutes. SFTV sets it. Values above 1440 (ie, 24 hours) seem to be considered invalid - if I set them the value instead ends up as 10 and the timeout flag gets cleared from the wakeup events field.

I've submitted a patch that adds a sysfs interface for setting these values, and unless anyone objects it'll probably end up in 3.11. There's still the remaining question of how userspace should make use of these, and also how installers should behave when it comes to systems that support IRST. As previously mentioned, there's no obvious indication to the OS that the feature is supported unless the appropriate partition already exists. The easiest way to deal with this is for installers to default to retaining any partitions with the magic IDs, but I'm still looking into whether it's possible to get the firmware to cough up some more information so it can be created automatically even if the drive's entirely blank.

And now, having got this working on a test machine, I just need to split my Thinkpad's swap partition in half and make sure it works here as well. Woo.

[1] Note: I am not going to do this.
[2] Conveniently, the same as the partition type that APM systems used for suspend to disk back when dubstep hadn't been invented yet
[3] At least, if you attempt to set them they get ignored.

comments

Hello OpenSsh 6.0 has been out for more than a year and the OpenSSH configuration editor still lacks the new parameters introduced by this release (like AllowAgentForwarding). Technically, the task is not difficult, but I lack time to address it: I m swamped by real life job, maintenance of Config::Model, Debian packaging activities So I m looking for volunteer(s) to help me on Config::Model. Updating OpenSSH model is a great way to start ! If you want to help, please:

• say so in a comment of this post or on config-model-users at lists.sourceforge.net (to synchronize efforts)
• Fork Config::Model::OpenSsh repository
• Follow instructions in the README file to install dependencies
• Read this wiki page that details how to upgrade OpenSSH model.
• Update and test the model
• Send a pull request (Note that I ll also accept patches sent by mail)

Be sure that you won t be forgotten in the change log Feel free to contact config-model-users at lists.sourceforge.net to get help, exchange ideas, or to discuss how to handle deprecation or upgrade of OpenSSH parameters All the best update: OpenSSH project name was corrected after Rafal s comment.
Tagged: Config::Model, OpenSsh, Perl

I have attended the SciPy 2013 conference in Austin, Texas. Here are my impressions.

Number one is the fact that the IPython notebook was used by pretty much everyone. I use it a lot myself, but I didn't realize how ubiquitous it has become. It is quickly becoming the standard now. The IPython notebook is using Markdown and in fact it is better than Rest. The way to remember the "[]()" syntax for links is that in regular text you put links into () parentheses, so you do the same in Markdown, and append [] for the text of the link. The other way to remember is that [] feel more serious and thus are used for the text of the link. I stressed several times to +Fernando Perez and +Brian Granger how awesome it would be to have interactive widgets in the notebook. Fortunately that was pretty much preaching to the choir, as that's one of the first things they plan to implement good foundations for and I just can't wait to use that.

It is now clear, that the IPython notebook is the way to store computations that I want to share with other people, or to use it as a "lab notebook" for myself, so that I can remember what exactly I did to obtain the results (for example how exactly I obtained some figures from raw data). In other words --- instead of having sets of scripts and manual bash commands that have to be executed in particular order to do what I want, just use IPython notebook and put everything in there.
Number two is that how big the conference has become since the last time I attended (couple years ago), yet it still has the friendly feeling. Unfortunately, I had to miss a lot of talks, due to scheduling conflicts (there were three parallel sessions), so I look forward to seeing them on video.

+Aaron Meurer and I have done the SymPy tutorial (see the link for videos and other tutorial materials). It's been nice to finally meet +Matthew Rocklin (very active SymPy contributor) in person. He also had an interesting presentation
about symbolic matrices + Lapack code generation. +Jason Moore presented PyDy.
It's been a great pleasure for us to invite +David Li (still a high school student) to attend the conference and give a presentation about his work on sympygamma.com and live.sympy.org.

It was nice to meet the Julia guys, +Jeff Bezanson and +Stefan Karpinski. I contributed the Fortran benchmarks on the Julia's website some time ago, but I had the feeling that a lot of them are quite artificial and not very meaningful. I think Jeff and Stefan confirmed my feeling. Julia seems to have quite interesting type system and multiple dispatch, that SymPy should learn from.

I met the VTK guys +Matthew McCormick and +Pat Marion. One of the keynotes was given by +Will Schroeder from Kitware about publishing. I remember him stressing to manage dependencies well as well as to use BSD like license (as opposed to viral licenses like GPL or LGPL). That opensource has pretty much won (i.e. it is now clear that that is the way to go).

I had great discussions with +Francesc Alted, +Andy Terrel, +Brett Murphy, +Jonathan Rocher, +Eric Jones, +Travis Oliphant, +Mark Wiebe, +Ilan Schnell, +St fan van der Walt, +David Cournapeau, +Anthony Scopatz, +Paul Ivanov, +Michael Droettboom, +Wes McKinney, +Jake Vanderplas, +Kurt Smith, +Aron Ahmadia, +Kyle Mandli, +Benjamin Root and others.


It's also been nice to have a chat with +Jason Vertrees and other guys from Schr dinger.

One other thing that I realized last week at the conference is that pretty much everyone agreed on the fact that NumPy should act as the default way to represent memory (no matter if the array was created in Fortran or other code) and allow manipulations on it. Faster libraries like Blaze or ODIN should then hook themselves up into NumPy using multiple dispatch. Also SymPy would then hook itself up so that it can be used with array operations natively. Currently SymPy does work with NumPy (see our tests for some examples what works), but the solution is a bit fragile (it is not possible to override NumPy behavior, but because NumPy supports general objects, we simply give it SymPy objects and things mostly work).

Similar to this, I would like to create multiple dispatch in SymPy core itself, so that other (faster) libraries for symbolic manipulation can hook themselves up, so that their own (faster) multiplication, expansion or series expansion would get called instead of the SymPy default one implemented in pure Python.

Other blog posts from the conference:

• Aaron's post
• Fernando's post

A backup run takes time. During a backup run the live data may change. This can mean that the snapshot of the live data may not be internally consistent. For example, suppose you're writing an e-mail when the backup starts automatically. If the timing goes wrong in exactly the right way, the backup might capture both the draft e-mail you were writing when the backup started, and the sent e-mail, when you finished the draft and sent the mail before the backup ended. Or, worse, the backup might miss both the draft and the sent e-mail. The next backup run will, certainly, get the sent e-mail, but what if you have a disaster before that happens? Internal consistency of data can be quite difficult to achive. Some programs, such as MySQL, don't do a good job of keeping the data consistent on-disk, making it difficult for the backup program to get a proper setup. (In that case, a standard trick is to "dump" or "export" the data in a consistent form, and back that up instead.) In an ideal situation, when the backup starts, the system would have a way to tell all running programs to store all their state on disk in a recoverable manner (save all open documents, dump data base content, etc), and once that is done, the backup program creates a snapshot of the filesystem. Unfortunately, I don't know of any operating system that can request consistent state from running applications. Snapshotting, however, is easy-peasy. It can be achieved by the filesystem (e.g., btrfs), or using LVM. Doing the snapshots requires root privileges, but that can probably be arranged. However, snapshotting like this, without getting all programs to commit their state to disk first, is not a guarantee of consistency. A thorough way to be consistent is to shut down the computer, and then reboot it into a special backup mode (similar to single-user mode), where no services or applications are running. However, this is, for most people, much too heavyweight a procedure to be worth it. Does consistency really matter? It matters a lot when the live data is being changed actively and consistency of the data is critical. For example, a bank's database of the amount of money in each account is quite critical: if data is not backed up consistently, money can be lost or created spontaneously, and that's probably a bad thing. Most people, however, don't need to worry a lot, and merely need to be aware of the issue, and perhaps mitigate it by backing up when the computer is mostly idle, and run backups often enough. Oh dear. This blog post contains too few jokes. I seem to have run out of jokes to make, so that will conclude this series of blog posts. I hope it was useful to some.

Running a pristine operating system is fun. I keep going to run programs and finding they're not installed! For example I'd planned to re-deploy the Debian Administration code-base this evening, but couldn't because fabric is not contained in Wheezy (#714421). Thankfully backporting the package was trivial, but it was a minor stumbling block. I've hit a few of those recently. Still in happier new my lumail mail client can now handle both adding attachments to outgoing mails and extracting them from incoming mails. There are missing features which some people might expect and rely upon, such as:

• Threading support.
• GPG support.

But that said the scripting primitives allow interesting things to be done and I'm enjoying the experience of writing something so "major". True I've got ~20 "stars" on github which isn't a great sign of popularity, but I have had some fun feedback and the client works for me. I'm going to have to spend a few days working on TAB-completion code that plays-nice with curses, because that's a major irritation (and you can't mix/match curses & readline, annoyingly). But otherwise I think we're getting close to being complete enough I'll slow down.

This blog post is the second of a series of posts dealing with the results of the Debian systemd survey. I intend to give a presentation at DebConf 2013, too, so you could either read my posts, or watch the talk, or both :-). It seems that it is unclear how Debian s transition to systemd is intended to work. By transition , we mean going from the current state (sysvinit is the default and fully supported) to systemd is fully supported. Then by merely installing systemd by default and letting it provide /sbin/init, we can make it the default init system. If and when that happens is a different matter and it s not necessary for all packages to have systemd support. sysvinit compatibility systemd natively supports sysvinit scripts, meaning your existing package will work as-is but you cannot utilize all the features that systemd provides. The sysvinit support works very well, as you can try in a fresh Debian wheezy VM. In the output of systemctl list-units , every entry which has an LSB: prefix is actually a sysvinit script. The mechanism with which systemd decides whether to use an init script or a service file is by looking whether a service file with a corresponding name exists. That is, if e.g. apache2.service exists, systemd will prefer it over /etc/init.d/apache2. To make this crystal clear: it is not necessary to ship service files for all services in some kind of flag day. systemd supports a mixed installation where some services use init scripts and some services use service files. Adding systemd support to your package In a nutshell, it usually works like this:

1. Install a service file to /lib/systemd/system/foo.service.
   Often, upstream already provides and installs a .service file.
   If not, you can place your file at debian/package.service
   Make sure that your service file name corresponds to the sysvinit script name
   (e.g. apache2.service for /etc/init.d/apache2)
2. Ensure your service file(s) are enabled and started.
   We strongly recommend you to use our package dh-systemd.
   If you use dh(1), add --with=systemd in debian/rules and Build-Dep on dh-systemd
3. Test your package, see the next section.

For details see wiki.debian.org/Systemd/Packaging. Testing systemd We carefully made sure that you can install the systemd Debian package on your machine alongside sysvinit without breaking anything. The systemd package does not conflict with any other packages, it will not replace /sbin/init and systemd will not be enabled right away. It is only after you specify the kernel parameter init=/bin/systemd in /etc/default/grub that you switch to systemd. In case you want to go back, simply boot without this kernel parameter. Conclusion In conclusion, the transition is straight-forward and the necessary infrastructure is in place. systemd is available in Debian and can be used today. Packages can add systemd support whenever their maintainer(s) feel like it. There is no need for a flag day. We can switch the default whenever we think we are ready.

Review: Dark Lies the Island, by Kevin Barry

Publisher:	Greywolf
Copyright:	2012
Printing:	2013
ISBN:	1-55597-651-4
Format:	ARC
Pages:	185

This is a literary short story collection by a mainstream Irish writer, rather far from my normal fare. It was the second book in a shipment of Powell's Indiespensable, which is generally (when there is one) a proof or Advanced Reading Copy of something relatively obscure. I'm not really the target audience, not being much of a short story aficionado, but the whole point of doing this Indiespensable experiment is to stretch my reading range. First off, as I would generally expect by mainstream fiction, the quality of the writing is excellent. One thing I particularly like about Barry is that he's refreshingly and unhesitatingly profane. His characters curse like I expect people to curse, some of them at the drop of a hat, and for me it gives a feel of solid realism to his dialogue. He's also very good with eye dialect, giving the impression of accents without making the text hard to read. Some of these stories I liked a great deal, rather more than I had expected. But if there was a general undermining flaw for me, it was that I prefer stories that go somewhere, that have a plot or lead up to a definite point. Some of Barry's do, but a lot of them seem more vignettes or just scenes, sketches of characters, that drift off without resolution. I can admire those as writing exercises, but for me they don't fill the desire I have when I sit down with a story. I'm not sure how useful these reviews will be, given that I don't have a lot of mainstream fiction background to compare them with, but here are some reactions, for whatever they're worth. "Across the Rooftops": This is one of those sketches, but it's one of the best of them. It's a single moment on the rooftops, an attempt to capture the moment of possibility around the first romantic overture. It's sadly quite conventional in gender roles (nervous man initiating, woman as relationship gatekeeper), but apart from that it's very well-written. This kind of thing is normally not to my taste, but Barry does such a great job capturing the sense of uncertainty and the sharp focus on detail that I couldn't help but like it. (7) "Wifey Redux": This is by far my favorite story of this book. I think it's both hilarious and brilliant, right from the starting line.

This is the story of a happy marriage but before you throw up and turn the page let me say that it will end with my face pressed hard into the cold metal of the Volvo's bonnet, my hands cuffed behind my back, and my rights droned into my ear this will occur in the car park of a big-box retail unit on the Naas Road in Dublin.

It's the story of a marriage and how it changes over time, but also the story of being a father and his baffled, flailing reactions to his daughter's sexual explorations. But that's not what makes the story. What makes the story is what leads up to the arrest at the end, which had me laughing out-loud in delight. Barry is great at writing a sort of devilish humor; I wish more of the collection was like this. (9) "Fjord of Killary": This is another one of the ones I enjoyed. It's about an author who buys a hotel (with a bar) on the fjord of Killary thinking that the local culture and contact along with the wild beauty would inspire his poetry. At the start of the story, he's thoroughly sick of both the climate and the people, and the collision between his idyllic dreams and the reality, as well as his acerbic first-person complaints, is quite entertaining. A huge storm and resulting flood provides the conflict and impetus for change, and a few moments of humor in the understated local reactions. I thought the closing epiphany was a bit too obvious and expected, and the ending didn't quite work for me, but it has some good moments. (7) "A Cruelty": Here's where the collection started losing me. This is still well-written and closely observed, but in the case of this story, I wish it weren't, since I found it extremely uncomfortable. The viewpoint character is vulnerable to an encounter of unalloyed nastiness. I'm sure that's the point, but, similar to how I avoid horror, it's the sort of story I'd rather not read. (3) "Beer Trip to Llandudno": This was my second-favorite story of the collection. It's about a group of men who take periodic beer-tasting trips and rate beers. They're just normal men, from a variety of backgrounds and professions, and I thought Barry did a great job capturing the sort of camaraderie that comes from long association with a hobby. That includes, here, the awkward limits on what one talks about and the tendency to use the hobby as a shield from anything that drifts into less certain territory. I thought the story suffered somewhat from not having much of a plot or conclusion, but that's also necessary from the setup. This group of people isn't actually going to solve problems, but will be there for each other in their own way. (8) "Ernestine and Kit": Another very dark story, although that's not quite as obvious at the start. As with "A Cruelty," it's well-written but disturbing and lacks any sort of positive resolution. Here, I think Barry went a bit far into portraying people who are a large part of the popular imagination but who are exceptionally rare in reality. It's the kind of story that, at least for me, plays badly with my brain's threat analysis: too memorable for the level of actual risk, and feeling like it was playing a bit too much with popular boogeymen. (4) "The Mainland Campaign": This one was just too subtle for me. Some of the summaries for this book hint at a meaning for the story that I didn't pick up at all on my first reading. On re-reading, I suspect that analysis is right, but even re-reading the story with that interpretation in mind (this is the sort of story where I'm not sure the average American would pick it up on first reading, but others might), I still don't understand exactly what happened. I think some mainstream writing, and some short stories, tends to err on the side of subtle. (4) "Wistful England": Another one that's way over on the sketch of a moment side of stories. Unlike "Across the Rooftops," it failed to make any impression on me whatsoever; I had to skim it just now to remind myself of any details at all, and by the time I edited this review for posting, I'd forgotten it again. I think it was aiming at capturing a mood, but the mopey viewpoint character didn't mean anything to me. (3) "Doctor Sot": This is another odd one, and I'm not quite sure what I think of it. Either it's another character sketch without much of a plot, or the plot was too subtle. The protagonist is a rather unlikable drunk who doubles as a small town's incompetent doctor. The story involves his encounter with a local sort of hippie encampment, which is moderately interesting even though I couldn't stand the man. Then it leads to an encounter that clearly meant something, but which was entirely lost on me. (4) "The Girls and the Dogs": And from an absence of plot back to the deeply disturbing. This story is about a moderately unlikable drug dealer who gets refuge from an extremely unlikable crazy person in a weird relationship with a woman and her sister. (As is sadly typical, polyamory only makes an appearance when the author wants to paint a scenario that's utterly fucked up and psychotic.) There's a pseudo-fantasy element here in that the characters talk about spells, but I think the only spell involved is authorial fiat to create a deeply broken and sick game that plays into a host of negative stereotypes. Despite myself, I did get drawn into the suspense of the story (Barry's undoubtedly a good writer), but it left me feeling dirty on several levels. (4) "White Hitachi": Finally, another story that I liked, although not as good as the ones earlier in the collection. This one follows a con man and two-bit thief as he gets his brother out of lockup and tries to resolve, or at least stay ahead of, various problems in his life. Again, no real ending, but I thought Barry did a good job at taking a snapshot of a life from a perspective that I don't read much in literature (along with all the sexism and racism that comes along with it). It sort of drifts off rather than ends (although the last sentence is a great bit of characterization), but I found it oddly enjoyable. (6) "Dark Lies the Island": I'm not sure what to make of this. It's another character sketch, a moment of deep psychological significance for a character, floating somewhat alone but described in detail. But the character is a girl struggling with cutting, from a male author whose other stories did not fill me with confidence in his handling of female characters. Barry makes this psychologically believable, but I'm a little nervous about trusting his portrayal of that mindset. It's also, again, just a bit too subtle; I had a hard time getting an emotional feel for how the events of the story connect. (5) "Berlin Arkonaplatz My Lesbian Summer": The final story of the collection is fairly typical of the problem I had with most of it. It seems reasonably well-written, I had a hard time connecting with the protagonist or understanding his motivations. It looks at a slice of life with which I have no familiarity at all (and is interesting for that reason), but I don't quite trust the story enough to submerge in it. Barry seems to write a lot of protagonists who seem aimless, befuddled, or just largely out of control, and I like a bit more agency in the primary character. Silvija is an interesting character, even shown from another's perspective, but the story is almost purely observational: showing her without comment, without obvious motive, and mostly without plot. It's strangely compelling, but not quite compelling enough that I'd actually seek it out. Which, really, is the whole book in a nutshell. (6) Rating: 6 out of 10

Just a quick note about a new release of the script I use to publish new software releases. I'm moving more packages to Module::Build, and I noticed I'd been pre-generating release tarballs for Perl modules and then using the release script to do the rest of the work. It supports building a release tarball from the Git repository, though, and by plugging into that machinery I could ensure that I run the test suite with the released code. That's now implemented for the Module::Build build system. Although I do think it's odd that ./Build disttest doesn't actually build a distribution, just acts like it will and then runs a test. You can get the latest version from my miscellaneous scripts page.