The two first interviews were dedicated to long-time Debian developers. This time I took the opposite approach, I interviewed David Kalnischkies who is not (yet) a Debian developer. But he s contributing to one of the most important software within Debian the APT package manager since 2009. You can already see him in many places in Debian sharing his APT knowledge when needed. English is not his native language and he s a bit shy, but he accepted the interview nevertheless. I would like to thank him for the efforts involved and I hope his story can inspire some people to take the leap and just start helping My questions are in bold, the rest is by David. Who are you? I am David Kalnischkies, 22 years old, living in the small town Erbach near Wiesbaden in Germany and I m studying computer science at the TU Darmstadt. Furthermore I am for more than half a decade now young group leader of my hometown. I never intended to get into this position, but it has similarities with my career in this internet-thingy here. I don t remember why, but in April 2009 I was at a stage that some simple bugs in APT annoyed me so much that I grabbed the source, and most importantly I don t know why I did it but I published my changes in Mai with #433007, a few more bugs and even a branch on launchpad. And this public branch got me into all this trouble in June: I got a mail from Mr. package managment Michael Vogt regarding this branch A few days later I joined an IRC session with him and closely after that my name appeared for the first time in a changelog entry. It s a strange but also addicting feeling to read your own name in an unfamiliar place. And even now after many IRC discussions, bugfixes and features, three Ubuntu Developer Summits and a Google Summer of Code in Debian, my name still appear in places I have never even thought about e.g. in an interview. What s your biggest achievement within Debian? I would like to answer MultiArch in APT as it was my Google Summer of Code project, but as it has (not much) use for the normal user at this point will hopefully change for wheezy I chose three smaller things in squeeze s APT that many people don t even know yet:

• MMap run out of room , the most famous error related to the APT::Cache-Limit option is gone. The DynamicMMap in APT now deserves its name
• Download and usage of multiple Translations of Descriptions
• crazy stuff like apt-cache show ^apt-.*$/experimental works

If your impression is now that I only do APT stuff: that s completely right, but that s already more than enough for me for now as the toolchain behind the short name APT contains so many tools and use cases that you always have something different. You re an active member of the APT development team. Are there plans for APT in Debian Wheezy? What features can we expect? That s very hard to answer, as the team is too small to be able to really plan something. I mean, you can have fancy plans and everything and half a second later someone arrives on the mailing list with a small question which eats days of development time just for debugging But right now the TODO list contains (in no particular order):

• MultiArch managing packages built for different architectures like i386 on amd64 to ease the usage of packages which only work on specific architectures or cross-compiling.
• rewriting the subsystem responsible for downloading files to e.g. enable tools like apt-file or debtags to reuse the infrastructure by plugging into it.
• splitting long descriptions out of the Packages file to possibly decrease the size to download on an apt-get update . Includes mostly pulling the button only to enable it by the archive masters
• backporting popular features of some frontends to enable all frontends to use them, e.g. apt-get changelog or apt-get download
• support research on resolver improvements by implementing support for a distribution independent upgrade problem format (CUDF).
• an additional single binary for users wrapping apt-get, apt-cache and co.
• getting in contact (again) with various forks like apt-rpm and derivatives like maemo or telesphoreo to join forces instead of splitting them by working on different (and possibily very old) heads of the dragon

We will see what will get real for wheezy and what is postponed, but one thing is sure: more will be done for wheezy if you help! If you could spend all your time on Debian, what would you work on? I would spend it on APT s debbugs count zero would be cool to look at! We make progress in this regard, but with the current velocity we will reach it in ten years or so. Reading more mailing lists would be interesting, as I am kind of an information junky. Maintaining a package could be interesting to share the annoyance of a maintainer with handcrafted dependencies just to notice that APT doesn t get it in the way I intended it to be. Through, to make it feel real I need to train a few new APT contributors before so they can point my mistake out, but this unfortunately doesn t depend so much on time but on victims Maybe I could even be working on getting an official status. Beside that, I would love to be able to apt-get dist-upgrade the increasing mass of systems I and many others carry around in their pockets. In regards to my phone, this is already fixed, but there is much room for improvements. What s the biggest problem of Debian? You need to be lucky. You need to talk at the right time to the right person. That s not really a debian-only problem as such, but in a global project full of volunteers you can see it clearly as there are plenty of opportunities to be unlucky. For example, it s unlikely that an interview would be made with me now if Michael had not contacted me in June 2009. In a big project like Debian, you are basically completely lost without a mentor guiding you, so things like the debian-mentors list are good projects, but I am pretty certain they could benefit from some more helping hands. The other thing which I consider a problem is that and I read from time to time some people don t care for translations. That s bad. Yes, a developer is able to read English, otherwise s/he couldn t write code or participate on the mailinglists. Still, I personally prefer to use a translated application if I have the chance as it s simply easier for me to read in my mother tongue, not only because I am dyslexic, but because my mind still thinks in German and not in English. Yes, I could personally fix that by thinking in English only from now on, but its a quite big problem to convince my family which is not really familiar with tech-stuff to use something if they can t understand what is written on screen. It was hard enough to tell my mother how to write an SMS in a German interface. My phone with English words all over the place would be completely unusable for her despite the fact that my phone is powered by Debian and better for the task from a technical point of view. You are not yet an official Debian developer/maintainer, but you re already perceived in the community as one the most knowledgeable person about APT. It s a great start! What s your advice to other people who want to start contributing to Debian in general, and to APT in particular? It was never a goal in my life to start contributing . My goal was and still is to make my life easier by letting the computer work for me. At some point APT hindered the success of this goal, so it needed to be fixed. I didn t expect to open pandora s box. So, my advice is simple: Just start. Ignore the warning signs telling you that this is not easy. They are just telling you that you do something useful. Only artificial problems are easy. Further more, contribution to APT, dpkg or any other existing package is in no way harder than opening an ITP and working on your own, and it s cooler as you have a similar minded team around you to talk to. APT didn t accept release codenames as target release was one of the first things I fixed. If I had asked someone if that would be a good starting point the answer would have been a clear no , but I didn t search for a good starting point As a kid I can start playing football by just walking on the field and play or I can sit near the field, watching the others play, while analyzing which position would be the best for me to start ruling out one by one as the technical requirements seem too high Oh bicycle kick that sounds complicated I can t do that Julian Andreas Klode is working on a APT replacement, there s also Cupt by Eugene V. Lyubimkin. Both projects started because their authors are not satisfied with APT, they find APT s code difficult to hack partly due to the usage of C++. Do you share their concerns and what s your opinion on those projects? I don t think C++ is a concern in this regard, after all cupt is currently rewritten to C++0x and APT2 started in vala and is now C + glib last time I checked at least. I personally think that something is wrong if we need to advertise an application by saying in which language it is written The major problem for APT is probably that the code is old : APT does its job for more than 12 years now, under different maintainers with an always changing environment around it: so there are lines in APT which date from a time when nobody knew what a Breaks dependency is, that packages can have long descriptions which can be translated or even that package archives can be signed with a gpg key! And yet we take all those for granted today. APT has proven to adapt to these changes in the environment and became in this process very popular. So I don t think the point is near (if it will come at all) that APT can go into retirement as it is completely replaced by something else. The competitors one the other hand have their first 12 years still to go. And it will be interesting to see how they will evolve and what will be the state of the art in 2022 But you asked what I think about the competitors: I prefer the revolution from inside simply because I can see effects faster as more users will profit from it now. Cupt and co. obviously prefer the normal revolution. The goal is the same, creating the best package manager tool, but the chosen way to the goal is different. aptitude and cupt have an interactive resolver for example: that s something I dislike personally, for others that is the ultimate killer feature. cupt reading the same preference file as APT will have a different pinning result, which we should consider each time someone mentions the word drop-in replacement . APT2 isn t much more than the name which I completely dislike currently from a user point of view, so I can t really comment on that. All of them make me sad as each line invested in boilerplate code like configuration file parsing would be in my eyes better be spent in a bugfix or new feature instead, but I am not here to tell anyone what they should do in their free time But frankly, I don t see them really as competitors: I use the tools I use, if other do that too that s good, if not that s their problem. The thing that annoys me really are claims like plan is to remove APT by 2014 as this generates a vi vs. emacs like atmosphere we don t need. If some people really think emacs is a good editor who cares? I really hope we all can drink a beer in 2022 in Milliways, the restaurant at the end of the package universe, remembering the good old 2010 Is there someone in Debian that you admire for his contributions? No, not one, many! Michael Vogt who has nearly the monopole of package manager maintainer by being upstream of APT, synaptics and software center to name only the biggest and still has the time to answer even the dumbest of my questions. Jason Gunthorpe for being one of the initial developers behind deity who I will probably never meet in person beside in old comments and commit logs. Christian Perrier for caring so much about translations. Obey Arthur Liu as a great admin for Debian s participation in Google s Summer of Code. Paul Wise for doing countless reviews on debian-mentors which are a good source of information not only for the maintainer of the package under review. I guess I need to stop here because you asked for just one. So let s end with some big words instead: I am just a little cog in the big debian wheel

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Thank you to David Kalnischkies for the time spent answering my questions. I hope you enjoyed reading his answers as I did. Subscribe to my newsletter to get my monthly summary of the Debian/Ubuntu news and to not miss further interviews. You can also follow along on Identi.ca, Twitter and Facebook.

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I attended a workshop sponsored by the IAB, W3C, ISOC and MIT on Internet Privacy. The workshop had much more of a web focus than it should have: the web is quite important should certainly cover a majority of the time, but backend issues, network issues, and mobile applications are certainly important too. For me this workshop was an excellent place to think about linkability and correlation of information. When people describe attacks such as using the ordered list of fonts installed in a web browser to distinguish one person from another, it s all too easy to dismiss people who want to solve that attack as the privacy fringe. Who cares if someone knows my IP address or what fonts I use? The problem is that computers are very good at putting data together. If you log into a web site once, and then later come back to that same website, it s relatively easy to fingerprint your browser and determine that it is the same computer. There s enough information that even if you use private browsing mode, clear your cookies and move IP addresses, it s relatively easy to perform this sort of linking. It s important to realize that partially fixing this sort of issue will make it take longer to link two things with certainty, but tends not to actually help in the long-run. Consider the font issue. If your browser returns the set of fonts it has in the order they are installed, then that provides a lot of information. Your fingerprint will look the same as people who took the same OS updates, browser updates and installed the same additional fonts in exactly the same order as you. Let s say that the probability that someone has the same font fingerprint as you is one in a million. For a lot of websites that s enough that you could very quickly be linked. Sorting the list of fonts reduces the information; in that case, let s say your probability of having the same font set as someone else is one in a hundred. The website gets much less information from the fonts. However it can combine that information with timing information etc. It can immediately rule out all the people who have a different font profile. However as all the other people who have the same font fingerprint access the website over time, differences between them and you will continue to rule them out until eventually you are left. Obviously this is at a high level. One important high-level note is that you can t fix these sorts of fingerprinting issues on your own; trying makes things far worse. If you re the only one whose browser doesn t give out a font list at all, then it s really easy to identify you. The big question in my mind now is how much do we care about this linking. Governments have the technology to do a lot with linking. We don t have anything we technical we can do to stop them, so we ll need to handle that with laws. Large companies like Google, Facebook and our ISPs are also in a good position to take significant advantage of linking. Again, though, these companies can be regulated; technology will play a part, especially in telling them what we re comfortable with and what we re not, but most users will not need to physically prevent Google and Facebook from linking their data. However smaller websites are under a lot less supervision than the large companies. Unless you take significant steps, such a website can link all your activities on that website. Also, if any group of websites in that space want to share information, they can link across the websites. I d like to run thought experiments to understand how bad this is. I d like to come up with examples of things that people share with small websites but don t want linked together or alternatively don t want linked back to their identity. Then look at how this information could be linked. However, I m having trouble with these thought experiments because I m just not very privacy minded. I can t think of something that I share on the web that I wouldn t link directly to my primary identity. I certainly can t find anything concrete enough to be able to evaluate how clearly I care to protect it. Helping me out here would be appreciated; if you can think of fairly specific examples. There s lots of important I prefer to keep private like credit card numbers, but there, it s not about linking at all. I can reasonably assume that the person I m giving my credit card number to has a desire to respect my privacy.a

As I mentioned recently, the Ubuntu Technical Board is reviewing the most popular topics in Ubuntu Brainstorm and coordinating official responses on behalf of the project. This means that the most popular topics on Ubuntu Brainstorm receive expert answers from the people working in these areas. This is the first batch, and we plan to repeat this process each quarter. We ll use feedback and experiences from this run to improve it for next time, so let us know what you think. Power management (idea #24782) Laptops are now outselling desktops globally, and laptop owners want to get the most out of their expensive and heavy batteries. So it s no surprise that people are wondering about improved power management in Ubuntu. This is a complex topic which spans the Linux software stack, and certainly isn t an issue which will be solved in the foreseeable future, but we see a lot of good work being done in this area. To tell us about it, Amit Kucheria, Ubuntu kernel developer and leader of the Linaro working group on Power Management, contributed a great writeup on this topic, with technical analysis, tips and recommendations, and a look at what s coming next.

I am going to attempt to summarize the various use profiles and what Ubuntu does (or can do) to prolong battery life in those profiles. Power management, when done right, should not require the user to make several (difficult) choices. It should just work providing a good balance of performance and battery life.

IP address conflicts (idea #25648) IP addressing is a subject that most people should never have to think about. When something isn t working, and two computers end up with the same IP address, it can be hard to tell what s wrong. I was personally surprised to find this one near the top of the list on Ubuntu Brainstorm, since it seems unlikely to be a very common problem. Nonetheless, it was voted up, and we re listening. There is a tool called ipwatchd which is already available in the package repository, and was created specifically to address this problem. This seems like a further indication that this problem may be more widespread than I might assume. The idea has already been marked as implemented in Brainstorm based on the existence of this package, but that doesn t help people who have never heard of ipwatchd, much less found and installed it. What do you think? Have you ever run into this problem? Would it have helped you if your computer had told you what was wrong, or would it have only confused you further? Is it worth considering this for inclusion in the default install? Post your comments in Brainstorm. Selecting the only available username to login (idea #6974) Although Linux is designed as a multi-user operating system, most Ubuntu systems are only used by one person. In that light, it seems a bit redundant to ask the user to identify themselves every time they login, by clicking on their username. Why not just preselect it? Indeed, this would be relatively simple to implement, but the real question is whether it is the right choice for users. Martin Pitt of the Ubuntu Desktop Team notes that consistency is an important factor in ease of use, and asks for further feedback.

So in summary, we favored consistency and predictablility over the extra effort to press Enter once. This hasn t been a very strong opinion or decision, though, and the desktop team would be happy to revise it.

Icon for .deb packages (idea #25197) Building on the invaluable efforts of Debian developers, we work hard to make sure that people can get all of the software they need from Ubuntu repositories through Software Center and APT, where they are authenticated and secure. However, in practice, it is occasionally necessary for users to work with .deb files directly. Brainstorm idea 25197 suggests that the icon used to represent .deb packages in the file manager is not ideal, and can be confusing. Matthew Paul Thomas of the Canonical Design Team responds with encouragement for deb-thumbnailer, which makes the icon both more distinctive and more informative. He has opened bug 685851 to track progress on getting it packaged and into the main repository.

I have reviewed the proposed solutions with Michael Vogt, our packaging expert. Solution #1 is straightforward, but we particularly like solutions #5 and #10, using a thumbnailer to show the application icon from inside each package.

Keeping the time accurate over the Internet by default (idea #25301) It s important for an Internet connected computer to know the correct time of day, which is why Ubuntu has included automatic Internet time synchronization with NTP since the very first release (4.10 warty ). So some of us were a little surprised to see this as one of the most popular ideas on Ubuntu Brainstorm. Colin Watson of the Ubuntu Technical Board investigated and discovered a case where this wasn t working correctly. It s now fixed for Ubuntu 11.04, and Colin has sent the patches upstream to Debian and GNOME.

My first reaction was hey, that s odd I thought we already did that? . We install the ntpdate package by default (although it s deprecated upstream in favour of other tools, but that shouldn t be important here). ntpdate is run from /etc/network/if-up.d/ntpdate, in other words every time you connect to a network, which should be acceptably frequent for most people, so it really ought to Just Work by default. But this is one of the top ten problems where users have gone to the trouble of proposing solutions on Brainstorm, so it couldn t be that simple. What was going on?

More detail in GNOME system monitor (idea #25887) Under System, Preferences, System Monitor, you can find a tool to peek under the hood at the Linux processes which power every Ubuntu system. Power users, hungry for more detail on their systems inner workings, voted to suggest that more detail be made available through this interface. Robert Ancell of the Ubuntu Desktop Team answered their call by offering to mentor a volunteer to develop a patch, and someone has already stepped up with a first draft. Help the user understand when closing a window does not close the app (idea #25801) When the user clicks the close button, most applications obediently exit. A few, though, will just hide, and continue running, because they assume that s what the user actually wants, and it can be hard to tell which has happened. Ivanka Majic, Creative Strategy Lead at Canonical, shares her perspective on this issue, with a pointer to work in progress to resolve it.

This is more than a good idea, it s an important gap in the usability of most of the desktop operating systems in widespread use today.

Ubuntu Software Centre Removal of Configuration Files (idea #24963) One feature of the Debian packaging system used in Ubuntu is that it draws a distinction between removing a package and purging it. Purging should remove all traces of the package, such that installing and then immediately purging a package should return the system to the same state. Removing will leave certain files behind, including system configuration files and sometimes runtime data. This subtle distinction is useful to system administrators, but only serves to confuse most end users, so it s not exposed by Software Center: it just defaults to removing packages. This proposal in Ubuntu Brainstorm suggests that Software Center should purge packages by default instead. Michael Vogt of the Ubuntu Foundations Team explains the reasoning behind this default, and offers an alternative suggestion based on his experience with the package management system.

This is not a easy problem and we need to carefully balance the needs to keep the UI simple with the needs to keep the system from accumulating cruft.

Ubuntu One file sync progress (idea #25417) Ubuntu One file synchronization works behind the scenes, uploading and downloading as needed to replicate your data to multiple computers. It does most of its work silently, and it can be hard to tell what it is doing or when it will be finished. John Lenton, engineering manager for the Ubuntu One Desktop+ team, posts on the AskUbuntu Q&A site with tools and tips which work today, and their plans to address this issue comprehensively in the future. Multimedia performance (idea #24878) With a cornucopia of multimedia content available online today, it s important that users be able to access it quickly and easily. Poor performance in the audio, video and graphics subsystems can spoil the experience, if resource-hungry multimedia applications can t keep up with the flow of data. Allison Randal, Ubuntu Technical Architect, answers with an analysis of the problem and the proposed solutions, an overview of current activity in this area, and pointers for getting involved.

The fundamental concern is a classic one for large systems: changes in one part of the system affect the performance of another part of the system. It s modestly difficult to measure the performance effects of local changes, but exponentially more difficult to measure the network effects of changes across the system.

With this weeks lawless governmental attacks on Wikileak and free speech, it has become obvious that PayPal, visa and mastercard can not be trusted to handle money transactions. A blog post from Simon Phipps on bitcoin reminded me about a project that a friend of mine mentioned earlier. I decided to follow Simon's example, and get involved with BitCoin. I got some help from my friend to get it all running, and he even handed me some bitcoins to get started. I even donated a few bitcoins to Simon for helping me remember BitCoin. So, what is bitcoins, you probably wonder? It is a digital crypto-currency, decentralised and handled using peer-to-peer networks. It allows anonymous transactions and prohibits central control over the transactions, making it impossible for governments and companies alike to block donations and other transactions. The source is free software, and while the key dependency wxWidgets 2.9 for the graphical user interface is missing in Debian, the command line client builds just fine. Hopefully Jonas will get the package into Debian soon. Bitcoins can be converted to other currencies, like USD and EUR. There are companies accepting bitcoins when selling services and goods, and there are even currency "stock" markets where the exchange rate is decided. There are not many users so far, but the concept seems promising. If you want to get started and lack a friend with any bitcoins to spare, you can even get some for free (0.05 bitcoin at the time of writing). Use BitcoinWatch to keep an eye on the current exchange rates. As an experiment, I have decided to set up bitcoind on one of my machines. If you want to support my activity, please send Bitcoin donations to the address 15oWEoG9dUPovwmUL9KWAnYRtNJEkP1u1b. Thank you!

I'm using WebDAV on Lenny and on Squeeze now for some time for syncing my bookmarks and calendars which is working just fine. But now I want to extend my WebDAV in order to use it as an external storage. The only problem is: it doesn't workon OSX! D'oh! Basically I followed several HowTos on the Net, so I ended with this configuration so far:

DavLockDB /path/to/DAVLockDB/DAVLockDB
<Directory /path/to/webdav/>
DAV On
AuthType Digest
AuthName "realm"
AuthUserFile /path/tot/.htdigest
Require valid-user
Options +Indexes
AllowOverride None
Order allow,deny
Allow from all
<LimitExcept GET PUT POST OPTIONS DELETE PROPFIND PROPPATCH MKCOL COPY MOVE LOCK UNLOCK>
RewriteEngine Off
</LimitExcept>
</Directory>

I can connect to and browse the WebDAV directory, but I can't upload new files - neither with Finder on OSX nor with cp on command line in OSX. When using Finder I get the following errors:

For non-Germans: it says that the process couldn't be completed because the object is still in use.

Error -36 seems to be a generic I/O error in OSX and you can find many hits when you do a search in your favorite search engine. The Apache logs report lots of these lines:

==> /var/log/apache2/domain-ssl-error.log <==
[Thu Dec 09 21:23:35 2010] [error] [client 2001:6f8:90e:900::2] client denied by server configuration: /var/www/net/domain/path/to/Files/._Cam-EG_20101113015900_MD 3.avi ==> /var/log/apache2/domain-ssl-access.log <==
[09/Dec/2010:21:23:35 +0100] rostock.ip6.windfluechter.net 2001:6f8:90e:900::2 - "GET /path/to/Files/._Cam-EG_20101113015900_MD%203.avi HTTP/1.1" 403 250 "-" "WebDAVFS/1.8.1 (01818000) Darwin/10.5.0 (i386)"

When copying some files with cp on OSXs command line I get these kind of errors:

$ cp -r Desktop/AIDAluna_KameraArchiv_Geiranger /Volumes/ij/Files/
cp: /Volumes/ij/Files/AIDAluna_KameraArchiv_Geiranger/PRIVATE/AVCHD: Operation not permitted
cp: Desktop/AIDAluna_KameraArchiv_Geiranger/PRIVATE/AVCHD: unable to copy extended attributes to /Volumes/ij/Files/AIDAluna_KameraArchiv_Geiranger/PRIVATE/AVCHD: Operation not permitted
cp: /Volumes/ij/Files/AIDAluna_KameraArchiv_Geiranger/PRIVATE/AVCHD/.DS_Store: No such file or directory
cp: /Volumes/ij/Files/AIDAluna_KameraArchiv_Geiranger/PRIVATE/AVCHD/AVCHDTN: No such file or directory

Funny enough directories were created and some files were copying although OSX complains about "Operation not permitted":

$ du -sch /Volumes/ij/Files/AIDAluna_KameraArchiv_Geiranger/*
10M /Volumes/ij/Files/AIDAluna_KameraArchiv_Geiranger/DCIM
2,5K /Volumes/ij/Files/AIDAluna_KameraArchiv_Geiranger/MISC
2,0K /Volumes/ij/Files/AIDAluna_KameraArchiv_Geiranger/PRIVATE
10M total

Of course the directory on the webserver has sufficient permissions and copying files to it is working just fine with Windows as well as Debian Sid. But anyway, is there something I'm missing in WebDAV configuration or can I do something in OSX to make it work? Using a third party application on OSX is something I would like to avoid, but when nothing else will help, I'm open for suggestions.

As part of my work for EDF, I ve had to package and integrate a set of tools for performance measurement and profiling of HPC code. This toolbox comprises tools for analysis of both sequential and parallel codes, MPI communications profiling and, of course, visualization frontends. Without going into too much details, here s the list:

• OpenSpeedShop: a complete performance and profiling workbench, including I/O and MPI
• PerfSuite: a relatively simple and easy to use performance analysis toolkit
• TAU: a complete performance analysis framework including automatic instrumentation with PDT
• Scalasca: a tool for performance optimization of parallel codes, including MPI communications
• a number of dependencies: slog2, Open Trace Format libraries, VampirTrace, dyninst, monitor, perfctr, pfmon, PAPI,
• visualization frontends: paraprof, jumpshot4, cube3,

If you ve been anywhere near HPC code, the names probably ring a bell; they re the best tools out there in their category, developed and used by the top laboratories. Over the past year, all the tools have received some level of testing, meaning we know they do work at the very least to some extent. As you can imagine, testing such tools is no easy task and takes an insane amount of time and resources of all kinds. Testing is all the more important that I had to produce a number of patches to integrate the tools properly in the distribution and, in some cases, to even get them to build. Now, we would like to share this work with the HPC community in and around Debian. How exactly we are going to do that isn t clear just yet; most probably, we ll end up building a team with other interested parties and offer our packages as a base to build upon. There are a number of challenges with these tools: they re not easy to build, they re not easy to maintain, they re not easy to use, they re not easy to understand. Basically, nothing is easy. Some of those tools were never meant to be packaged and integrated in a distribution and no sane amount of patching will fix that, so we have to live with packages that aren t quite as polished as we like them to be. And then, there are licenses. Some tools are non-free due to usage restrictions. Others rely on non-free dependencies. Although I ve been looking at the licenses, a thorough license check will be required and decisions will need to be made. It s not for the faint of heart! If you are interested in these tools and in bringing them to Debian, please get in touch. I ve also had to package the Apache Derby database (Java); if someone out there cares about Derby, I d be more than happy to provide my packages as a start base for getting Derby into Debian. The packages need some work by someone who knows a thing or two about Derby and who can test and enhance the packaging of the server part.

I'll start with an apology that I didn't get any pictures this weekend. However, many, many other people did. This weekend started with a simple holiday supper for Sonia's work (ok, there was some Karaoke). Then it moved on to the crazy. Saturday was Santacon. I pre-partied with Sonia's crew (she even stopped in on her lunch break). Then had a delivery of 1/2 Cord of firewood that will be well used over the coming year. Then it was back to SantaCon still dressed as an Elf to meet up with Lina. Then back to Sonia's crew to bring Sonia her reindeer antlers that I'd forgotten to drop off at her place. (ok, there was some stops for karaoke, Lina was at the Mint, and Sonia was at Encore).

Sunday was as crazy as Saturday, but not as long. The Santa Skivvies run was a simple get dressed down to the bare essentials of red underwear and a santa hat, then run into the Castro from The Lookout, and back. Since any Santa event wouldn't be complete with only Santas, Sonia dressed and Santa and I was the red-nosed reindeer (complete with reins). (ok, there was no karaoke on sunday (the Mint was closed on the way home from The Lookout).

As part of the Training Sessions initiative organized by the Debian Women project, this Thursday we will hold a lesson on how to use the Debian Bug Tracking System.

Like the previous sessions, this lesson will take place on #debian-women on irc.debian.org, at 19:00 UTC on Thursday 9th December.

Logs will be available immediately after the lesson at the usual place and a wiki tutorial will be created a few days later. You might want to follow our group on identi.ca for further information!

See you on Thursday!

Contributed by: Francesca Ciceri

The ProblemMy SE Linux Play Machine has been down for a couple of weeks. I ve changed to a cheaper Internet access plan which also allows me to download a lot more data, but I don t have a static IP address any more and my ISP seems to change the IP a lot more often than I ve experienced in the past (I m used to having a non-static IP address not change for months rather than hours). So I needed to get Dynamic DNS working. Naturally I wasn t going to use one of the free or commercial Dynamic DNS solutions, I prefer to do things myself. So my Play Machine had to remain offline until I fixed this.The Solutiondyn IN NS ns.sws.net.au.
IN NS othello.dycom.com.au.
play IN CNAME play.dyn.coker.com.au.The first thing I did was to create a separate zone file, I put the above records in my main zone file to make play.coker.com.au be a CNAME for play. and dyn.coker.com.au is a dynamic domain. I have SE Linux denying BIND the ability to write to the primary zone file for my domain to make it slightly more difficult for an attacker to insert fake DNS records (they could of course change the memory state of BIND to make it serve bogus data). The dynamic zone file is stored where BIND can write it and therefore a BIND exploit could easily replace it (but such an attack is out of the scope of the Play Machine project so don t get any ideas).Another reason for separating the dynamic data is that BIND journals changes to a dynamic zone and therefore if you want to manually edit it you have to delete the journal, stop BIND, edit the file, and then restart BIND. One of the things that interests me is setting up dynamic DNS for some of my clients, as a constraint is that my client must be able to edit the zone file themself I have to keep the editing process for the main zone file relatively simple.dnssec-keygen -a hmac-md5 -b 128 -n host foo-dyn.keyI used the above command to create the key files. It created Kfoo-dyn.key.+X+Y.key and Kfoo-dyn.key.+X+Y.private where X and Y are replacements for numbers that might be secret.key "foo" algorithm hmac-md5; secret "XXXXXXXX"; ;
zone "dyn.coker.com.au"
type master;
file "/var/cache/bind/dyn.coker.com.au";
allow-update key "foo"; ;
allow-transfer key ns; ;
;I added the above to the BIND configuration to create the dynamic zone and allow it to be updated by this key. The value which I replaced with XXXXXXX in this example came from Kfoo-dyn.key.+X+Y.key. I haven t found any use for the .private file in this mode of operation. Please let me know if I missed something.Finally I used the following shell script to take the IP address from the interface that is specified on the command-line and update the DNS with it. I chose a 120 second timeout because i will sometimes change IP address often and because the system doesn t get enough hits for anyone to care about DNS caching.#!/bin/bash
set -e
IP=$(ip addr list $1 sed -n -e "s/\/.*$//" -e "s/^.*inet //p")
nsupdate -y foo:XXXXXXXX << END
update delete play.dyn.coker.com.au A
update add play.dyn.coker.com.au 120 A $IP
send
ENDTodoIt is supposed to be possible to use the -k option to nsupdate to specify a file containing the key. Reading a key file prevents another process on the same system from from using ps to discover the key which is a good security benefit. But as the security of my dynamic DNS isn t that important to me and I have SE Linux restricting which domains can see all processes in ps output this isn t a big concern for me.I would appreciate any suggestions on how to get -k working.

LWN has a recent article titled The dark side of open source conferences which concerns sexual assault at conferences [1].There are a significant number of comments with attempts to derail the discussion in ways that can really only be interpreted as attacks on Autistic people. The claims seem to be that the problem is not violent sexual assault at conferences, but guys on the Autism Spectrum who hit on girls when they don t want it. Naturally no supporting evidence was made for such claims. But that doesn t stop the discussion which has a logical end-point of excluding people like me from conferences.The IronyI think it s ironic that those who are making claims about what they call empathy disorders have failed to be Empathic by not realising the following things:

• Women who start a discussion about serious sexual assault probably aren t going to be happy if someone starts talking about chat-up attempts. While unwanted chat-up attempts are unpleasant they are in a different category and mixing them seems to be diminishing the significance of violent attack.
• Most members of a minority group (in this case women in the Free Software community) probably don t want discussions of how to help their group diverted by discussions that attack another minority group. What looks a lot like a divide and conquer attack against minority groups isn t going to be appreciated by members of either group and probably members of other minority groups who see what s happening aren t going to like it.
• There is no reason why people should require significant exposure to members of a minority group to treat them in a decent manner. The claim that we need more women at conferences so that men can get used to them and not treat them badly is ridiculous. Among the many stupid aspects of that idea is forgetting the fact that women comprise 52% of the population in first-world countries and we all deal with women every day. Women at IT conferences are not fundamentally different from women in the rest of society.
• When most people interpret your writing in a way other than what you intended it seems to be a reasonable assumption that you failed to explain things clearly. Telling everyone who disagrees to get therapy is unlikely to help convey your point. Telling people to get therapy is particularly likely to get a bad reaction if you are discussing something that actually involves dealing with psychologists.
• When there is an obvious resource on the Internet relating to a topic it s a good idea to read it instead of just making stuff up. Failing to do so will be taken as an indication that you aren t trying to be Empathic. The Wikipedia section on Autism Spectrum Disorders has a lot of useful information [2]. Please read it before making comments about Autism and Empathy.
• Having to be told how other people feel is not inherently a sign of a lack of Empathy. Asking people how they feel because you can t work it out is a sign of Empathy as it indicates an acknowledgement that other people have different emotions and you probably don t understand them all. The people who know that they can t understand other people and listen when told are probably better than average when it comes to Empathy.
• Finally what people say about themselves and their own experiences should be taken seriously.

Some Final PointsInstead of talking about how some other people should be more Empathic it seems that a better idea would be to try and demonstrate Empathy. Set a positive example.I did a Google search for Empathy Disorder and found this interesting article [3]. It s about how Neuro-Typical people (people who aren t on the Autism Spectrum) can learn to be more Empathic, it s probably more relevant to the issue of Empathy in the free software community than discussions of Autism.I think that the experience of a lot of people on the Autism Spectrum is similar to mine. It s not that we can t work things out it s just that it takes a lot longer. For things that can t be worked out in real time we have rules based on past experience. Naturally the rules include don t touch people and don t try to chat up women at conferences .Here is a link to my previous post on this topic [4].Update: I ve clarified some of the writing and added an extra point about having to be told how others feel.

• [1] https://lwn.net/Articles/417952/
• [2] http://en.wikipedia.org/wiki/Empathy#Autism_spectrum_disorders
• [3] http://articles.cnn.com/2008-06-18/living/o.empathy_1_empathy-friend-disorder
• [4] http://etbe.coker.com.au/2010/12/03/aspie-social-skills-free-software/

Ooops. It seems that while I worked on the script generating the release critical bug stats, I accidentally also published the stats, although it's not friday. Sorry for that, but while we are at it: I implemented two tiny changes:

1. The Ultimate Debian Database know about claimed bugs and uploads to deferred/delayed, too. So we can also take them into account.
2. Each number is now linked to the respective view of the UDDs web interface, making it easier to browse through the actual bugs.

I especially hope that the later change will make it easier to RC bug hunters to find something interesting. I also fixed the error naming UDD Universal Debian database instead of ultimate. Sorry, I know I was pointed to it quite some time ago, and I really thought I fixed it allready... Update: Don't missuse a quote symbol, but link the numbers directly.

(This is a part of a series of posts on my recent experience with Windows; see Windows (I) and Windows (II): User Interface.)

Every GNU/Linux desktop distribution hangs on a package management system as a foundation, and as a result the packaging systems are quite advanced, while Windows is stuck with those pesky installation wizards. There have been several stabs to implement a package system for Windows (see here), but none seem to have caught on.

There are three main disadvantages on not having good package management: tedium of manual installation, no dependency resolution and no system-wide automatic updates. In practice they are less important than it might seem. Installation wizards are indeed tedious, but in terms of time I found them to be quick enough to get through. Moreover, apps tend to be less specialized and more encompassing than Linux utilities, and as a result you do not need to install as many things as in Linux. For the same reason dependency resolution is not as important: there are few dependencies in general. As for automatic updates, most high-profile apps have integrated mechanisms to deal with that, however, I found that those mechanisms tended to result in nagging the user with messages. After a while I started ignoring the update notifications. I suspect that happens to many users.

The one thing that Windows has going for it is simplicity. You download installation binaries and you run them, and that's it. Linux package systems tend to be very complicated, and if (when) they break, you will need serious sysadmin chops to deal with the problem. Also installing specific versions (either older ones, or newer ones not yet available in the distro) of specific apps/libraries can be unnecessarily complicated, and the dependency graph limits your actions. In my experience, Windows does well enough without all this complexity as long as you don't reinstall your system too often.

As for the other complaints, I frequently run into the restriction of moving/editing files opened by another application. Coming from Linux, that one is stupidly annoying. Furthermore, it is frustrating not to be able to move inactive (or stuck) background windows. I really miss my unified filesystem namespace. Also there's quite a bit of nagging in general on Windows which I would rather do without. In the end, these are not dealbreakers though.

In my next (and probably final) post I will discuss software development on Windows.

Richard Tibbetts has called me out for conflating Web 2.0 startups with all startups in my recent blog posting, Google has a problem retaining great engineers? Bullcrap . His complaint was that I was over generalizing from Web 2.0 startups to all startups. He s right, of course. The traditional technology startup by definition does have a large amount technology work that needs to be done, in addition to the business development work. However, things have changed a lot even for technology startups. Consider a company like Sequent Computer Systems, which started in 1983. At the time the founders had a key idea, which was to use multiple commodity intel CPU s to create first SMP, and then later, NUMA minicomputers. But in order to do that, they had to design, build and manufacture a huge mount of hardware, as well as develop a whole new Unix-derived operating system, just to bring that core idea to market. These days, the founder or founders will have a core idea, which they will hopefully patent, to prevent competitors from replicating their work, just as before. However, these days there is a huge selection of open source software so there is much less technology that needs to be re-developed / re-invented in order to bring that idea to market. From Linux and BSD at the operating system level, to databases like MySQL, Apache web servers, etc., there is an awful lot for the startup to chose from. This is all goodness, of course. But it means that most of the technology developed in a typical startup will tend to be focused on supporting the core idea that was developed by the founder. If a company is focused on databases, they probably won t be interested in supporting me to do my file system work. Why should they? There s lots of open source file systems they can use; one of them will probably meet their needs. So while it s obvious that you can do technology at large variety of companies, of different sizes, I don t think it s arrogance to say that there are certain types of technology that can only be done at Google, or maybe at a very small subset of other companies. I m pretty confident, for example, that Google has the world s largest number of computers in its various data centers around the world. That means there are certain things that don t make sense at other companies, but which absolutely makes sense at our scale. In addition, Google s business model means allows us to pursue open source projects such as Chrome and Android that wouldn t make sense at other companies. With Android in particular, it means that multiple firmware updates for any given handset model, if it causes people to use the web more and drive more advertising revenue, makes sense and so it s something we can pursue in comparison to Nokia, which gets its revenue from hardware sales, so a firmware update that extends the life of a handset is actually a bad thing for them; better to force you to upgrade an handset every year or two. So I think Richard misunderstood me if he thought I was trying to make the argument that Google is the only place where you can do interesting technical work. That s obviously not true, of course. But I do think there are many examples of technical work which don t make business sense to do at smaller companies, and startups in particular have to be very much focused on bringing the founder s idea to market, and all else has to be subordinated to that goal. And one of the most interesting developments is how the combination of commoditized and standardized hardware, and comoditized software in the form of open source, has changed the game for startups. For most startups, though, open source software is something that they will use, but not necessarily develop except in fairly small ways. Many of the economic arguments in favor of releasing code as open source, and dedicating a significant fraction of an engineer s time to serve as a OSS project maintainer or kernel subsystem maintainer, are ones that make much more sense at a very large company like Google or IBM. That s not because startups are evil, or deficient in any way; just the economic realities that at a successful startup, everything has to be subordinated to the central goal of proving that they have a sustainable, scalable business model and that they have a good product/market fit. Everything else, and that includes participating in an open source community, is very likely a distraction from that central goal. No related posts.

Richard Tibbetts has called me out for conflating Web 2.0 startups with all startups in my recent blog posting, Google has a problem retaining great engineers? Bullcrap . His complaint was that I was over generalizing from Web 2.0 startups to all startups. He s right, of course. The traditional technology startup by definition does have a large amount technology work that needs to be done, in addition to the business development work. However, things have changed a lot even for technology startups. Consider a company like Sequent Computer Systems, which started in 1983. At the time the founders had a key idea, which was to use multiple commodity intel CPU s to create first SMP, and then later, NUMA minicomputers. But in order to do that, they had to design, build and manufacture a huge mount of hardware, as well as develop a whole new Unix-derived operating system, just to bring that core idea to market. These days, the founder or founders will have a core idea, which they will hopefully patent, to prevent competitors from replicating their work, just as before. However, these days there is a huge selection of open source software so there is much less technology that needs to be re-developed / re-invented in order to bring that idea to market. From Linux and BSD at the operating system level, to databases like MySQL, Apache web servers, etc., there is an awful lot for the startup to chose from. This is all goodness, of course. But it means that most of the technology developed in a typical startup will tend to be focused on supporting the core idea that was developed by the founder. If a company is focused on databases, they probably won t be interested in supporting me to do my file system work. Why should they? There s lots of open source file systems they can use; one of them will probably meet their needs. So while it s obvious that you can do technology at large variety of companies, of different sizes, I don t think it s arrogance to say that there are certain types of technology that can only be done at Google, or maybe at a very small subset of other companies. I m pretty confident, for example, that Google has the world s largest number of computers in its various data centers around the world. That means there are certain things that don t make sense at other companies, but which absolutely makes sense at our scale. In addition, Google s business model means allows us to pursue open source projects such as Chrome and Android that wouldn t make sense at other companies. With Android in particular, it means that multiple firmware updates for any given handset model, if it causes people to use the web more and drive more advertising revenue, makes sense and so it s something we can pursue in comparison to Nokia, which gets its revenue from hardware sales, so a firmware update that extends the life of a handset is actually a bad thing for them; better to force you to upgrade an handset every year or two. So I think Richard misunderstood me if he thought I was trying to make the argument that Google is the only place where you can do interesting technical work. That s obviously not true, of course. But I do think there are many examples of technical work which don t make business sense to do at smaller companies, and startups in particular have to be very much focused on bringing the founder s idea to market, and all else has to be subordinated to that goal. And one of the most interesting developments is how the combination of commoditized and standardized hardware, and comoditized software in the form of open source, has changed the game for startups. For most startups, though, open source software is something that they will use, but not necessarily develop except in fairly small ways. Many of the economic arguments in favor of releasing code as open source, and dedicating a significant fraction of an engineer s time to serve as a OSS project maintainer or kernel subsystem maintainer, are ones that make much more sense at a very large company like Google or IBM. That s not because startups are evil, or deficient in any way; just the economic realities that at a successful startup, everything has to be subordinated to the central goal of proving that they have a sustainable, scalable business model and that they have a good product/market fit. Everything else, and that includes participating in an open source community, is very likely a distraction from that central goal. No related posts.

If you ever have the misfortune of accidentally passing the path to a directory containing 177GB of data to the rm -rf command, I'll start by suggesting that you hit ctl-c. The sooner the better. Next, assuming you have some sort of backup, you'll be staring at two monumentally large data sets, wondering exactly what was deleted from the original. With help from dkg, I learned somethings about rm -rf. For one, it deletes one top level directory at a time. So - a comparison of the top level directory listings of the original and backup is a good place to start. Top level directories that are entirely missing in the original are easy to restore. However, the presence of a top level directory in the original doesn't mean it was un-touched. Next, you'll want to figure out which top level directory rm was operating on when you hit ctl-c. dkg discovered that ls -UR will provide a listing in the same order that rm -rf uses. The -U means do not sort. Note - the unsorted listing of the backup directory might not be the same as the unsorted listing of the original, so ls -UR is only really helpful on the original directory. After selecting the first top level directory, rm -rf seems to delete all files in that directory first (presumably in the same order that ls -UR will list them), then it enters the first sub directory (as returned by ls -UR) and repeats the process. With a careful comparison of ls -UR on the original with the directory listings on the backup, you should be able to pinpoint the exact sub directories affected, allowing you to restore only the files and directories that you deleted. Thanks to dkg for technical and blog title suggestions.

The relationship between Debian and Ubuntu has been the subject of many vigorous debates over the years, ever since Ubuntu s launch in 2004. Six years later, the situation has improved and both projects are communicating better. The Natty Narwhal Ubuntu Developer Summit (UDS) featured like all UDS for more than 2 years a Debian Health Check session where current cooperation issues and projects are discussed. A few days after that session, Lucas Nussbaum gave a talk during the mini-Debconf Paris detailing the relationship between both projects, both at the technical and social level. He also shared some concerns for Debian s future and gave his point of view on how Debian should address them. Both events give valuable insights on the current state of the relationship. Lucas Nussbaum s Debian-Ubuntu talk Lucas started by introducing himself. He s an Ubuntu developer since 2006 and a Debian developer since 2007. He has worked to improve the collaboration between both projects, notably by extending the Debian infrastructure to show Ubuntu-related information. He attended conferences for both projects (Debconf, UDS) and has friends in both communities. For all of these reasons, he believes himself to be qualified to speak on this topic. Collaboration at the technical level He then quickly explained the task of a distribution: taking upstream software, integrating it in standardized ways, doing quality assurance on the whole, delivering the result to users, and assuring some support afterward. He pointed out that in the case of Ubuntu, the distribution has one special upstream: Debian. Indeed Ubuntu gets most of its software from Debian (89%), and only 7% are new packages coming from other upstream projects (the remaining 4% are unknown, they are newer upstream releases of software available in Debian but he was not able to find out whether the Debian packaging had been reused or not). From all the packages imported from Debian, 17% have Ubuntu-specific changes. The reasons for those changes are varied: bugfixes, integration with Launchpad/Ubuntu One/etc., or toolchain changes. The above figures are based on Ubuntu Lucid (10.04) while excluding many Ubuntu-specific packages (language-pack-*, language-support-*, kde-l10n-*, *ubuntu*, *launchpad*). The different agendas and the differences in philosophy (Debian often seeking perfect solutions to problems; Ubuntu accepting temporary suboptimal workarounds) also explain why so many packages are modified on the Ubuntu side. It s simply not possible to always do the work in Debian first. But keeping changes in Ubuntu requires a lot of work since they merge with Debian unstable every 6 months. That s why they have a strong incentive to push changes to upstream and/or to Debian. There are 3 channels that Ubuntu uses to push changes to Debian: they file bug reports (between 250 to 400 during each Ubuntu release cycle), they interact directly with Debian maintainers (often the case when there s a maintenance team), or they do nothing and hope that the Debian maintainer will pick up the patch directly from the Debian Package Tracking System (it relays information provided by patches.ubuntu.com). Lucas pointed out that those changes are not the only thing that Debian should take back. Ubuntu has a huge user base resulting in lots of bug reports sitting in Launchpad, often without anyone taking care of them. Debian maintainers who already have enough bugs on their packages are obviously not interested in even more bugs, but those who are maintaining niche packages, with few reports, might be interested by the user feedback available in Launchpad. Even if some of the reports are Ubuntu-specific, many of them are advance warnings of problems that will affect Debian later on, when the toolchain catches up with Ubuntu s aggressive updates. To make this easier for Debian maintainers, Lucas improved the Debian Package Tracking System so that they can easily get Ubuntu bug reports for their packages even without interacting with Launchpad. Human feelings on both sides Lucas witnessed a big evolution in the perception of Ubuntu on the Debian side. The initial climate was rather negative: there were feelings of its work being stolen, claims of giving back that did not match the observations of the Debian maintainers, and problems with specific Canonical employees that reflected badly on Ubuntu as a whole. These days most Debian developers find something positive in Ubuntu: it brings a lot of new users to Linux, it provides something that works for their friends and family, it brings new developers to Debian, and it serves as a technological playground for Debian. On the Ubuntu side, the culture has changed as well. Debian is no longer so scary for Ubuntu contributors and contributing to Debian is The Right Thing to do. More and more Ubuntu developers are getting involved in Debian as well. But at the package level there s not always much to contribute, as many bugfixes are only temporary workarounds. And while Ubuntu s community follows this philosophy, Canonical is a for-profit company that contributes back mainly when it has compelling reasons to do so. Consequences for Debian In Lucas s eyes, the success of Ubuntu creates new problems. For many new users Linux is a synonym for Ubuntu, and since much innovation happens in Ubuntu first, Debian is overshadowed by its most popular derivative. He goes as far as saying that because of that Debian becomes less relevant . He went on to say that Debian needs to be relevant because the project defends important values that Ubuntu does not. And it needs to stay as an independent partner that filters what comes out of Ubuntu, ensuring that quality prevails in the long term. Fixing this problem is difficult, and the answer should not be to undermine Ubuntu. On the contrary, more cooperation is needed. If Debian developers are involved sooner in Ubuntu s projects, Debian will automatically get more credit. And if Ubuntu does more work in Debian, their work can be showcased sooner in the Debian context as well. The other solution that Lucas proposed is that Debian needs to communicate on why it s better than Ubuntu. Debian might not be better for everybody but there are many reasons why one could prefer Debian over Ubuntu. He listed some of them: Debian has better values since it s a volunteer-based project where decisions are made publicly and it has advocated the free software philosophy since 1993. On the other hand, Ubuntu is under control of Canonical where some decisions are imposed, it advocates some proprietary web services (Ubuntu One), the installer recommends adding proprietary software, and copyright assignments are required to contribute to Canonical projects. Debian is also better in terms of quality because every package has a maintainer who is often an expert in the field of the package. As a derivative, Ubuntu does not have the resources to do the same and instead most packages are maintained on a best effort basis by a limited set of developers who can t know everything about all packages. In conclusion, Lucas explained that Debian can neither ignore Ubuntu nor fight it. Instead it should consider Ubuntu as a chance and should leverage it to get back in the center of the FLOSS ecosystem . The Debian health check UDS session While this session has existed for some time, it s only the second time that a Debian Project Leader was present at UDS to discuss collaboration issues. During UDS-M (the previous summit), this increased involvement from Debian was a nice surprise to many. Stefano Zacchiroli the Debian leader collected and shared the feedback of Debian developers and the session ended up being very productive. Six months later is a good time to look back and verify if decisions made during UDS-M (see blueprint) have been followed through. Progress has been made On the Debian side, Stefano set up a Derivatives Front Desk so that derivative distributions (not just Ubuntu) have a clear point of contact when they are trying to cooperate but don t know where to start. It s also a good place to share experiences among the various derivatives. In parallel, a #debian-ubuntu channel has been started on OFTC (the IRC network used by Debian). With more than 50 regulars coming from both distributions, it s a good place for quick queries when you need advice on how to interact with the distribution that you re not familiar with. Ubuntu has updated its documentation to prominently feature how to cooperate with Debian. For example, the sponsorship process documentation explains how to forward patches both to the upstream developers and to Debian. It also recommends ensuring that the patch is not Ubuntu-specific and gives some explanation on how to do it (which includes checking against a list of common packaging changes made by Ubuntu). The Debian Derivative Front Desk is mentioned as a fallback when the Debian maintainer is unresponsive. While organizing Ubuntu Developer Week, Ubuntu now reaches out to Debian developers and tries to have sessions on working with Debian . Launchpad has also been extended to provide a list of bugs with attached patches and that information has been integrated in the Debian Package Tracking system by Lucas Nussbaum. Still some work to do Some of the work items have not been completed yet: many Debian maintainers would like a simpler way to issue a sync request (a process used to inject a package from Debian into Ubuntu). There s a requestsync command line tool provided by the ubuntu-dev-tools package (which is available in Debian) but it s not yet usable because Launchpad doesn t know the GPG keys of Debian maintainers. Another issue concerns packages which are first introduced in Ubuntu. Most of them have no reason to be Ubuntu-specific and should also end up in Debian. It has thus been suggested that people packaging new software for Ubuntu also upload them to Debian. They could however immediately file a request for adoption (RFA) to find another Debian maintainer if they don t plan to maintain it in the long term. If Ubuntu doesn t make this effort, it can take a long time until someone decides to reintegrate the Ubuntu package into Debian just because nobody knows about it. This represents an important shift in the Ubuntu process and it s not certain that it s going to work out. As with any important policy change, it can take several years until people are used to it. Both issues have been rescheduled for this release cycle, so they re still on the agenda. This time the UDS session was probably less interesting than the previous one. Stefano explained once more what Debian considers good collaboration practices: teams with members from both distributions, and forwarding of bugs if they have been well triaged and are known to apply to Debian. He also invited Ubuntu to discuss big changes with Debian before implementing them. An interesting suggestion that came up was that some Ubuntu developers could participate in Debcamp (one week hack-together before Debconf) to work with some Debian developers, go through Ubuntu patches, and merge the interesting bits. This would nicely complement Ubuntu s increased presence at Debconf: for the first time, community management team member Jorge Castro was at DebConf 10 giving a talk on collaboration between Debian and Ubuntu. There was also some brainstorming on how to identify packages where the collaboration is failing. A growing number of Ubuntu revisions (identified for example by a version like 1.0-1ubuntu62) could indicate that no synchronization was made with Debian, but it would also identify packages which are badly maintained on the Debian side. If Ubuntu consistently has a newer upstream version compared to Debian, it can also indicate a problem: maybe the person maintaining the package for Ubuntu would be better off doing the same work in Debian directly since the maintainer is lagging or not doing their work. Unfortunately this doesn t hold true for all packages since many Gnome packages are newer in Ubuntu but are actively maintained on both sides. Few of those discussions led to concrete decisions. It seems most proponents are reasonably satisfied with the current situation. Of course, one can always do better and Jono Bacon is going to ensure that all Canonical teams working on Ubuntu are aware of how to properly cooperate with Debian. The goal is to avoid heavy package modifications without coordination. Conclusion The Debian-Ubuntu relationships used to be a hot topic, but that s no longer the case thanks to regular efforts made on both sides. Conflicts between individuals still happen, but there are multiple places where they can be reported and discussed (#debian-ubuntu channel, Derivatives Front Desk at derivatives@debian.org on the Debian side or debian@ubuntu.com on the Ubuntu side). Documentation and infrastructure are in place to make it easier for volunteers to do the right thing. Despite all those process improvements, the best results still come out when people build personal relationships by discussing what they are doing. It often leads to tight cooperation, up to commit rights to the source repositories. Regular contacts help build a real sense of cooperation that no automated process can ever hope to achieve.

This article was first published in Linux Weekly News. You can get my monthly summary of the Debian/Ubuntu news, all you have to do is to click here to subscribe to my free newsletter.

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The Ubuntu Technical Board is currently conducting a review of the top ten Brainstorm issues users have raised about Ubuntu, and Matt asked me to investigate and respond to Idea #25301: Keeping the time accurate over the Internet by default. My first reaction was "hey, that's odd - I thought we already did that?". We install the ntpdate package by default (although it's deprecated upstream in favour of other tools, but that shouldn't be important here). ntpdate is run from /etc/network/if-up.d/ntpdate, in other words every time you connect to a network, which should be acceptably frequent for most people, so it really ought to Just Work by default. But this is one of the top ten problems where users have gone to the trouble of proposing solutions on Brainstorm, so it couldn't be that simple. What was going on? I brought up a clean virtual machine with a development version of Natty (the current Ubuntu development version, which will eventually become 11.04), and had a look in its logs: it was indeed synchronising its time from ntp.ubuntu.com, and I didn't think anything in that area had changed recently. On the other hand, I had occasionally noticed that my own laptop wasn't always synchronising its time quite right, but I'd put it down to local weirdness as my network isn't always very stable. Maybe this wasn't so local after all? So, I started tracing through the scripts to figure out what was going on. It turned out that I had an empty /etc/ntp.conf file on my laptop. The /usr/sbin/ntpdate-debian script assumed that that meant I had a full NTP server installed (I don't), and fetched the list of servers from it; since the file was empty, it ended up synchronising time from no servers, that is, not synchronising at all. I removed the file and all was well. That left the question of where that file came from. It didn't seem to be owned by any package; I was pretty sure I hadn't created it by hand either. I had a look through some bug reports, and soon found ntpdate 1:4.2.2.p4+dfsg-1ubuntu2 has a flawed configuration file. It turns out that time-admin (System -> Administration -> Time and Date) creates an empty /etc/ntp.conf file if you press the reload button (tooltip: "Synchronise now"), as part of an attempt to update NTP configuration. Aha! Once I knew where the problems were, it was easy to fix them. I've uploaded the following changes, which will be in the 11.04 release:

• Disregard empty ntp.conf files in ntpdate-debian.
• Remove an empty /etc/ntp.conf file on fresh installation of the ntp package, so that it doesn't interfere with creating the normal configuration file.
• Don't create the NTP configuration file in the time-admin backend if it doesn't exist already.

I've also sent these changes to Debian and GNOME as appropriate. There are still a few problems. The "Synchronise now" button doesn't work quite right in general (bug #90524), and if your network doesn't allow time synchronisation from ntp.ubuntu.com then you'll have to change the value of NTPSERVERS in /etc/default/ntpdate. Furthermore, the time-admin interface is confusing and makes it seem as though the default is not to synchronise the time automatically; this interface is being redesigned at the moment, which should be a good opportunity to make it less confusing, and I will contact the designers to mention this problem. On the whole, though, I think that many fewer people should have this kind of problem in Ubuntu 11.04. It's always possible that I missed some other problem that breaks automatic time synchronisation for people. Please do file a bug report if it still doesn't work for you in 11.04, or contact me directly (cjwatson at ubuntu.com).

As a first step on the road to evaluating different configuration management systems, I set up two VMs to test out puppet. Puppet is conveniently packaged within Debian so client and server installation was very simple. By default, puppet clients will look for a host named puppet on the local network, so by naming the server sensibly the two started talking to each other. puppetca --sign [client hostname] on the server started the ball rolling. My first test configuration was to add a user to the sudoers file. With CF Engine 2, I would have achieved this by using editfiles to check for a regular expression and insert a line if necessary. I stumbled across some CF Engine-style definitions for puppet in a Debian Administration article (taken originally from puppet's own wiki, which have since been moved/deleted) and achieved it using

append_if_no_such_line   sudo:
  file => "/etc/sudoers",
  line => "jon ALL=(ALL) ALL"
 

I'm a little concerned that this approach to problem solving is no better than CF Engine 2, and in fact worse than how I'd do it with CF Engine 2: if the host had a line with a different quantity of whitespace, such as jon ALL=(ALL) ALL, it won't match exactly and a duplicate line will be appended, whereas with CF Engine 2 I would have checked for something like ^jon \+ALL=(ALL) \+ALL$. I set up my work laptop as another test node, and used puppet to install some packages that I commonly use:

class jon-desktop  
  package   ['icedove', 'git-core', 'vim-gnome', 'vinagre', 'build-essential',
             'devscripts', 'subversion', 'git-buildpackage', 'mutt',
             'offlineimap', 'ascii', 'gitk', 'chromium-browser'
            ]: ensure => installed  
 

This worked fine, but is a little verbose and the package list is awkward to maintain buried inside the puppet syntax. I spent some time trying to see whether I could populate a puppet list based on the contents of a file: then I could list the packages one-per-line in a separate file. I haven't found a way of doing that yet. Using my laptop as a second node also exposed some interesting puppet client behaviour. Once I went off-site, the laptop tried to look up puppet on foreign networks (such as my home network). I would have assumed that, once the strong SSL association had been made, the client would try to connect to the FQDN of the server. This probably isn't a serious problem in practice, as we probably won't need to rely on nodes off-site talking to the configuration server, but I hope that the client doesn't trust any host that happens to answer to puppet... I fixed this by hacking my hosts file to include an entry for puppet. I could maintain this hack using Puppet itself, which would protect me against stale definitions if any renumbering takes place. I could also have added a line

server = puppet.fqdn.example.org

in /etc/puppet/puppet.conf, which is a more robust way of solving the problem.

This week I had to write a little tool that would collect input on different channels, via socket / netcat, via a http server, .... Calls for a parralel Design -- Maybe a good place to write something real in Erlang. While erlang itself was really nice to write -- I do like Prolog as well as the bunch of functional languages -- doing networking in erlang seems a bit special, the interfaces just aren't thin wrappers around the libc stuff. Getting a Socket Text interface What sounds like a easy challenge to accomplish was actually harder than expected. All I found was some way to pass binaries representing erlang code over a socket and evaluating it remotle. While it's nice that such things are as easy to do as they are it doesn't help me with my task of moving simple strings.

start() ->
     ok, Listen  = gen_tcp:listen(51622, [binary,  packet, 0 ,
                                          reuseaddr, true ,
                                          active, true ]),
    spawn(fun () -> accept_loop(Listen) end).
accept_loop(Listen) ->
     ok, Socket  = gen_tcp:accept(Listen),
    accept_loop(Listen),
    handle(Socket)
handle(Socket) ->
    receive
         tcp, Socket, Bin  ->
            io:format("~p~n", binary_to_list(Bin));
         tcp_closed, Socket  ->
            Buffer
    end.

So the socket is now up and receives text as wanted. However, as we are already runnign a parralel program it would be nice to be hable to handle multiple socket connections in parralel right? For that we just need to add a spawn() at the right place. The right place is not the handle(Socket) but the accept_loop(Listen) because the process that called accept will receive all the tcp messages. This last part was quite obvious after finding the documentation of the active, _ properties for the socket. always here means that you'll receive all data from the socket as erlang Messages, once delivers one package and waits until it is activated again and false requires calling a method -- this would have been possible as well when forking handle(Socket). The web server Ok we also want a webserver. We do not want to run some webapplication inside appache or so, just do some post/get and simple pages. Erlang here provides a built-in httpd with some mod_esi that calls some function depending on the URL used. It doesn't do anything fancy like templating or DB backends or stuff, just taking strings and building the http answers. Unfortunately there are no examples around and basically noone seems to be using this combination (apart from some hacks like mine probably). So as I needed to get some additional information into the handler function (a Pid to connect to some service), I, as a novice, just couldn't find a way. Asking on IRC the solution was rather simple: Just using erlang's process registry. For more complex stuf gproc might prove usefull here. Result I guess I've got a huge step farther in programming erlang now. The manpages are easily found by your search engine -- for python I have to either walk through the (well structured) online documentation or search for the right link in the search results, for erlang they're typically first. Also Joe Armstrong's Books as proven usefull. The most dificult part probably is getting around all the nice extras you can do (transfering functions over sockets et al) and find out how to do the thing you need.

A few weeks ago it became apparent to me that I may end up having to run Windows on my work PC. We're getting new machines soon with Vista images preloaded. There's a Linux image option (of unknown base, but possibly Ubuntu), but I've kinda been assuming that I could continue in my current approach - I run Debian, and accept that IT won't give me any support in doing so other than caring about the hardware. Seems like a reasonable deal to me. Except it requires an infrastructure that's platform agnostic, and that's the problem. There's a danger our new bug tracking system is much, much happier in IE than anything else. That's kinda a problem if I can't access it. The event last week was around a web streamed meeting, which is annoying but not as critical. I was unhappy at this realization. Very unhappy. And yet I had trouble finding the words to explain why. I don't do Linux advocacy these days (I'm not sure I ever really did). I probably gave up at the point my parents' bought a replacement machine for my mother while I was living in England and went for a Windows box (she'd been running Debian) because "they had knowledge of that in the house given I wasn't around". And then promptly rang me after it arrived to ask how to configure networking. Anyway. If I can't come up with some decent reasons about why I run Linux over Windows then I can't justifiably complain if I end up with a Windows desktop. So I think I need to collect together some thoughts about it. I'll try to break them up into a bunch of separate posts rather than one huge dump that no one will read. Let's start with the obvious: Familiarity This was the first question a coworker asked; is it because you're used to Linux? And it would be untruthful to say that doesn't play a part. I've been running Linux on the desktop for the past 12 years or so (well, I had few years running FreeBSD on my primary desktop too, but close enough). The only time I've ended up with a Windows desktop was when I worked for Aviva. I don't currently have a working Windows install anywhere. I have little experience of working with Windows these days. I mean, I can do it, but I don't find it comfortable (to the extent that I managed about 3 hours when I ended up with a Windows desktop back in August before installing Debian on it). That's the argument often used to stay with Windows (as per my parents, above). And it's not accurate. Why did I try Linux in the first place, and stick with it long enough to get to this point?