Search Results: "berin"

7 December 2016

Shirish Agarwal: Day trip in Cape Town, part 2

Debconf16 logo The post continues from the last post shared. Let me get some interesting tit-bits not related to the day-trip out-of-the-way first I don t know whether we had full access to see all parts of fuller hall or not. Couple of days I was wondering around Fuller Hall, specifically next to where clothes were pressed. Came to know of the laundry service pretty late but still was useful. Umm next to where the ladies/gentleman pressed our clothes, there is a stairway which goes down. In fact even on the opposite side there is a stairway which goes down. I dunno if other people explored them or not. The jail inside and under UCT I was surprised and shocked to see bars in each room as well as connecting walkways etc. I felt a bit sad, confused and curious and went on to find more places like that. After a while I came up to the ground-level and enquired with some of the ladies therein. I was shocked to know that UCT some years ago (they were not specific) was a jail for people. I couldn t imagine that a place which has so much warmth (in people, not climate) could be evil in a sense. I was not able to get much information out of them about the nature of jail it was, maybe it is a dark past that nobody wants to open up, dunno. There were also two *important* aspects of UCT which Bernelle either forgot, didn t share or I just came to know via the Wikipedia page then but nothing else. 1. MeerKAT Apparently quite a bit of the technology was built-in UCT itself. This would have been interesting for geeks and wanna-be geeks like me 2. The OpenContent Initiative by UCT This would have been also something worth exploring. One more interesting thing which I saw was the French council in Cape Town from outside The French Council in cape town from outside I would urge to look at the picture in the gallery as the picture I shared doesn t really show all the details. For e.g. the typical large french windows which are the hall-mark of French architecture doesn t show its glory but if you look at 1306 2322 original picture instead of the 202 360 reproduction you will see that. You will also the insignia of the French Imperial Eagle whose history I came to know only after I looked it up on the Wikipedia page on that day. It seemed fascinating and probably would have the same pride as the State Emblem of India has for Indians with the four Asiatic Lions standing in a circle protecting each other. I also like the palm tree and the way the French Council seemed little and yet had character around all the big buildings. What also was interesting that there wasn t any scare/fear-build and we could take photos from outside unlike what I had seen and experienced in Doha, Qatar as far as photography near Western Embassies/Councils were concerned. One of the very eye-opening moments for me was also while I was researching flights from India to South Africa. While perhaps unconsciously I might have known that Middle East is close to India, in reality, it was only during the search I became aware that most places in Middle East by flight are only an hour or two away. This was shocking as there is virtually no mention of one of our neighbours when they are source of large-scale remittances every year. I mean this should have been in our history and geography books but most do not dwell on the subject. It was only during and after that I could understand Mr. Modi s interactions and trade policies with the Middle East. Another interesting bit was seeing a bar in a Sprinbok bus spingbok atlas bar in bus While admittedly it is not the best picture of the bar, I was surprised to find a bar at the back of a bus. By bar I mean a machine which can serve anything from juices to alcoholic drinks depending upon what is stocked. What was also interesting in the same bus is that the bus also had a middle entrance-and-exit. The middle door in springbok atlas This is something I hadn t seen in most Indian buses. Some of the Volvo buses have but it is rarely used (only except emergencies) . An exhaustive showcase of local buses can be seen here . I find the hand-drawn/cad depictions of all the buses by Amit Pense near to the T. Axe which can be used to break windows Emergency exit window This is also something which I have not observed in Indian inter-city buses (axe to break the window in case of accident and breakable glass which doesn t hurt anyone I presume), whether they are State-Transport or the high-end Volvo s . Either it s part of South African Roads Regulations or something that Springbok buses do for their customers. All of these queries about the different facets I wanted to ask the bus-driver and the attendant/controller but in the excitement of seeing, recording new things couldn t ask In fact one of the more interesting things I looked at and could look day and night is the variety of vehicles on display in Cape Town. In hindsight, I should have bought a couple of 128 GB MMC cards for my mobile rather than the 64 GB one. It was just plain inadequate to capture all that was new and interesting. Auditorum chair truck seen near Auditorium This truck I had seen about some 100 metres near the Auditorium on Upper Campus. The truck s design, paint was something I had never seen before. It is/was similar to casket trucks seen in movies but the way it was painted and everything made it special. What was interesting is to see the gamut of different vehicles. For instance, there were no bicycles that I saw in most places. There were mostly Japanese/Italian bikes and all sorts of trucks. If I had known before, I would definitely have bought an SD specifically to take snaps of all the different types of trucks, cars etc. that I saw therein. The adage/phrase I should stop in any one place and the whole world will pass me by seemed true on quite a few South African Roads. While the roads were on par or a shade better than India, many of those were wide roads. Seeing those, I was left imagining how the Autobahn in Germany and other high-speed Expressways would look n feel. India has also been doing that with the Pune-Mumbai Expressway and projects like Yamuna Expressway and now the extension Agra Lucknow Expressway but doing this all over India would take probably a decade or more. We have been doing it since a decade and a half. NHDP and PMGSY are two projects which are still ongoing to better the roads. We have been having issues as to should we have toll or no toll issues but that is a discussion for some other time. One of the more interesting sights I saw was the high-arched gothic-styled church from outside. This is near Longstreet as well. high arch gothic-styled church I have seen something similar in Goa, Pondicherry but not such high-arches. I did try couple of times to gain entry but one time it was closed, the other time some repairing/construction work was going on or something. I would loved to see it from inside and hopefully they would have had an organ (music) as well. I could imagine to some extent the sort of music that would have come out. Now that Goa has come in the conversation I can t help but state that Seafood enthusiasts/lover/aficionado, or/and Pescatarianism would have a ball of a time in Goa. Goa is on the Konkan coast and while I m eggie, ones who enjoy seafood really have a ball of a time in Goa. Fouthama s Festival which happens in February is particularly attractive as Goan homes are thrown open for people to come and sample their food, exchange recipes and alike. This happens around 2 weeks before the Goan Carnival and is very much a part of the mish-mashed Konkani-Bengali-Parsi-Portugese culture. I better stop here about the Goa otherwise I ll get into reminiscing mode. To put the story and event back on track from where we left of (no fiction hereon), Nicholas was in constant communication with base, i.e. UCT as well as another group who was hiking from UCT to Table Mountain. We waited for the other group to join us till 13:00 hrs. We came to know that they were lost and were trying to come up and hence would take more time. As Bernelle was with them, who was a local and she had two dogs who knew the hills quite well, it was decided to go ahead without them. We came down the same cable-car and then ventured on towards Houtbay. Houtbay has it all, a fisherman s wharf, actual boats with tough-mean looking men with tattoos working on boats puffing cigars/pipes, gaggle of sea-gulls, the whole scene. Sharing a few pictures of the way in-between. the view en-route to Houtbay western style car paint and repair shop Tajmahal Indian Restaurant, Houtbay I just now had a quick look at the restaurant and it seems they had options for veggies too. Unfortunately, the rating leaves a bit to be desired but then dunno as Indian flavoring is something that takes time to get used too. Zomato doesn t give any idea of from when a restaurant is in business and has too few reviews so not easy to know how the experience would have been. Chinese noodles and small houses Notice the pattern, the pattern of small houses I saw all the way till Houtbay and back. I do vaguely remember starting a discussion about it on the bus but don t really remember. I have seen (on TV) cities like Miami, Dubai or/and Hong Kong who have big buildings on the beach but both in Konkan as well as Houtbay there were small buildings. I guess a combination of zoning regulations, feel of community, fear of being flooded all play into beaches being the way they are. Also, this probably is good as less stress on the environment. Miamiboyz from Wikimedia Commons The above picture is taken from Wikipedia from the article Miami Beach, Florida for comparison. Audi rare car to be seen in India The Audi rare car to be seen in India. This car has been associated with Ravi Shastri when he won it in 1985. I was young but still get goosebumps remembering those days. first-glance-Houtbay-and-pier First glance of Houtbay beach and pier. Notice how clean and white the beach is. Wharf-Grill-Restaurant-from-side-and-Hop-on-Hop-off-bus You can see the wharf grill restaurant in the distance (side-view), see the back of the hop on and hop off bus (a concept which was unknown to me till then). Once I came back and explored on the web came to know this concept is prevalent in many a touristy places around the world. Umm also By sheer happenchance also captured a beautiful looking Indian female . So many things happening all at once In Hindi, we would call this picture virodabhas or contradiction . this is in afternoon, around 1430 hrs. You have the sun, the clouds, the Mountains, the x number of boats, the pier, the houses, the cars, the shops. It was all crazy and beautiful at the same time. The Biggest Contradiction is seeing the Mountain, the beach and the Sea in the same Picture. Baffled the mind. Konkan though is a bit similar there as well. You have all the three things in some places but that s a different experience altogether as ours is a more tropical weather although is one of the most romantic places in the rains. We were supposed to go on a short cruise to seal/dolphin island but as we were late (as had been waiting for the other group) didn t go and instead just loitered there. Fake-real lookout bar-restaurant IIRC the lookout bar is situated just next to Houtbay Search and Rescue. Although was curious if the Lookout tower was used in case of disappearance. lost people, boats etc. Seal in action Seal jumping over water, what a miracle ! One of the boats on which we possibly could have been on. It looked like the boat we could have been on. I clicked as I especially liked the name Calypso and Calypso . I shared the two links as the mythologies, interpretation differ a bit between Greek and Hollywood culture Debian folks and the area around Can see few Debian folks in the foreground, next to the Pole and the area around. Also can see a bit of the area around. Alone boy trying to surf I don t know anything about water sports and after sometime he came out. I was left wondering though, how safe he was in that water. While he was close to the pier and he was just paddling, there weren t big waves still felt a bit of concern. Mr. Seal - the actor and his handler While the act was not to the level we see in the movies, still for the time I hung around, I saw him showing attitude for his younger audiences, eating out of their hands, making funny sounds. Btw he farted a few times, whether that was a put-on or not can t really say but produced a few guffaws from his audience. A family feeding Mr. Seal I dunno why the birds came down for. Mr. Seal was being fed oily small fish parts, dunno if the oil was secreted by the fish themselves or whatever, it just looked oily from distance. Bird-Man-Bird Bird taking necessary sun bath typical equipment on a boat to catch fish-lot of nets boats-nets-and-ropes People working on disentangling a net There wasn t much activity on the time we went. It probably would have been different on sunrise and would be on sunset. The only activity I saw was on this boat where they were busy fixing and disentangling the lines. I came up with 5-15 different ideas for a story but rejected them as a. Probably all of them have been tried. People have been fishing since the beginning of time and modern fishing probably 200 odd years or so. I have read accounts of fishing companies in early 1800s onwards, so probably all must have been tried. b. More dangerous one, if there is a unique idea, then it becomes more dangerous as writing is an all-consuming process. Writing a blog post (bad or good) takes lots of time. I constantly read, re-read, try and improvise till I can or my patience loses out. In book you simply can t have such luxuries. hout-bay-search-and-rescue-no-parking-zone No parking/tow zone in/near the Houtbay search and rescue. Probably to take out emergency vehicles once something untoward happens. hout-bay-sea-rescue-with-stats Saved 54 lives, boats towed 154 Salut! Houtbay sea rescue. The different springbok atlas bus that we were on kraal-kraft The only small criticism is for Houtbay there wasn t a single public toilet. We had to ask favor at kraal kraft to use their toilets and there could have been accidents, it wasn t lighted well and water was spilled around. Road sign telling that we are near to UCT For us, because we were late we missed both the boat-cruise as well as some street shops selling trinkets. Other than that it was all well. We should have stayed till sunset, I am sure the view would have been breath-taking but we hadn t booked the bus till evening. Back at UCT Overall it was an interesting day as we had explored part of Table Mountain, seen the somewhat outrageously priced trinkets there as well as explored Houtbay sea-side as well.
Filed under: Miscellenous Tagged: #Audi, #Cape Town, #Cruises, #Debconf16, #French Council, #Geography, #Houtbay Sea Rescue, #Jail, #Middle East, #Springbok Atlas, #Vehicles

13 November 2016

Andrew Cater: Debian MiniConf, ARM Cambridge, 13/11/12 - Day 4 post 2

Just watching Lars Wirzenius talking about Qvarn - identity and data protection management on large scale. Compliant with EC data/identity management regulations and concerns.

The room fell silent at 1100 for two minutes - as we did on Friday 11/11/12.
This is remembering the dead, wounded and those affected by the wars of the 20th and 21st centuries.

Inevitably, it also reminded me of friends and colleagues in Debian that are no longer with us: for Espy and so many others before and since, thanks from me - you are well remembered here.

1 November 2016

Jonathan Wiltshire: Reflecting on a year of regular, public IRC meetings

The release team first started holding a regular, public planning and status meeting a little over a year ago, in September 2015. At that time, FTP masters had experimented along similar lines and I took some inspiration from that, including the keeping of proper minutes that anyone can look at. I wanted to open up our discussion processes and allow other developers and users to see (and perhaps influence) our plans for the release taking shape month by month, and how we reached certain decisions with a lot of mature discussion and not just on a whim. A secondary aim, since we are quite geographically distributed and getting together for same-room meetings is hard, was to bring more accountability to ourselves when we decided something ought to happen; if it s in the minutes, there s no escaping someone asking so what happened to ? . That s worked better for us on some topics than on others. Finally, public minutes mean that anyone who might be interested in joining the team can see easily what we re up to and how we shape the release throughout the cycle. That might help lower the barrier to entry, which can only be good for the team. I had hoped that regular meetings would inspire other teams to do similar; I haven t seen any indication of that to date (though perhaps it s just down to awareness). The Reproducible Builds contributors held fortnightly meetings for a period in 2015, though not inspired by ours, and I heard recent talk of starting those again. I still think that there is plenty of scope to improve the transparency of core teams in general in Debian, but also that regular meetings aren t going to work for every team. A regular slot which is not varied except when absolutely necessary, is essential for avoiding the temptation to just push it back another week when things are busy. In our office we have an allegedly-regular Thursday afternoon slot for technical demonstrations, which has suffered from exactly that problem for a long time now, and I wanted to avoid that issue. We have a calendar to remind us when each meeting is due, along with other important events like freeze milestones. Our slot is the fourth Wednesday of the month, a fairly arbitrary choice which seems to have worked out quite well. Time zones are more of an issue, even within Europe. We have mostly used a European evening time, but that s not very helpful further West where it s in the middle of the working day, or the middle of the night if you re further East (that one fortunately isn t an issue for us so far). Even within Europe it s difficult, as we have to try and balance commuting time in the UK with dinner on the continent, or dinner with late evening, or adjust for saving changes, or you get the idea. If we gained a far-eastern team member one day, this would be a real issue. We use Meetbot for recording the minutes. I have heard criticism that it publicly archives IRC logs to the web essentially forever, but for us that s the whole point. With a little practice and discipline it does generate really nice minutes, with a bullet summary of the important parts, a summary of actions agreed and a log of the conversation for detailed reference. Anybody reading them can see how we reached a conclusion, and I m of the view that goes some way to avoiding a reputation for cabal-ism. It does pay to use the #info, #agree and #action tags liberally, but other things are slightly unnatural like always remembering to use a URL at the beginning of a line and not in the middle of a sentence, or Meetbot doesn t notice it. Practice goes a long way. I ve naturally fallen into chairing most meetings, for better or worse the consistency seems beneficial, but I worry that I m dominating the discussion sometimes. Discipline in making sure everybody has been included is something I ve had to get better at. It s essential to have a public agenda and to stick to it, and it should include some stock items at the start and end (including making sure the URL to the previous minutes has been given, reviewing outstanding actions, and arranging the next meeting before ending the current one). There is some skill in judging the agenda length and deciding which items can be deferred to make sure it doesn t drag on too late we ve found anything more than an hour is far too long, and between 45 and 60 minutes is pushing it. Getting some easy topics out of the way before starting one which is more contentious can be helpful to avoid having to defer them later. I circulate the URL to the minutes and the date of the next meeting publicly on the mailing list immediately after each meeting, or as soon as possible. With little feedback, I have no idea if our meetings are helpful to those outside the team or not. We do still hold in-person meetings from time to time when we re all together, because they re useful for some circumstances (like some genuinely private topics we occasionally need to discuss, or for sprinting). I would hope that public meetings inspire confidence that we re on top of the release process, that they show we have a mature and transparent decision making process (for example, in deciding to move the freeze date to accommodate an external release schedule as a one-off, and subsequently deciding to not move it back when circumstances changed), and mostly that other teams might benefit for the same reasons. But I can also see that they make more sense in a team with a defined project cycle than they might in one which is more administrative or where work is more sporadic (no point holding a meeting for the sake of it, after all).

17 October 2016

Russell Coker: Improving Memory

I ve just attended a lecture about improving memory, mostly about mnemonic techniques. I m not against learning techniques to improve memory and I think it s good to teach kids a variety of things many of which won t be needed when they are younger as you never know which kids will need various skills. But I disagree with the assertion that we are losing valuable skills due to digital amnesia . Nowadays we have programs to check spelling so we can avoid the effort of remembering to spell difficult words like mnemonic, calendar apps on our phones that link to addresses and phone numbers, and the ability to Google the world s knowledge from the bathroom. So the question is, what do we need to remember? For remembering phone numbers it seems that all we need is to remember numbers that we might call in the event of a mobile phone being lost or running out of battery charge. That would be a close friend or relative and maybe a taxi company (and 13CABS isn t difficult to remember). Remembering addresses (street numbers etc) doesn t seem very useful in any situation. Remembering the way to get to a place is useful and it seems to me that the way the navigation programs operate works against this. To remember a route you would want to travel the same way on multiple occasions and use a relatively simple route. The way that Google maps tends to give the more confusing routes (IE routes varying by the day and routes which take all shortcuts) works against this. I think that spending time improving memory skills is useful, but it will either take time away from learning other skills that are more useful to most people nowadays or take time away from leisure activities. If improving memory skills is fun for you then it s probably better than most hobbies (it s cheap and provides some minor benefits in life). When I was in primary school it was considered important to make kids memorise their times tables . I m sure that memorising the multiplication of all numbers less than 13 is useful to some people, but I never felt a need to do it. When I was young I could multiply any pair of 2 digit numbers as quickly as most kids could remember the result. The big difference was that most kids needed a calculator to multiply any number by 13 which is a significant disadvantage. What We Must Memorise Nowadays the biggest memory issue is with passwords (the Correct Horse Battery Staple XKCD comic is worth reading [1]). Teaching mnemonic techniques for the purpose of memorising passwords would probably be a good idea and would probably get more interest from the audience. One interesting corner-case of passwords is ATM PIN numbers. The Wikipedia page about PIN numbers states that 4-12 digits can be used for PINs [2]. The 4 digit PIN was initially chosen because John Adrian Shepherd-Barron (who is credited with inventing the ATM) was convinced by his wife that 6 digits would be too difficult to memorise. The fact that hardly any banks outside Switzerland use more than 4 digits suggests that Mrs Shepherd-Barron had a point. The fact that this was decided in the 60 s proves that it s not digital amnesia . We also have to memorise how to use various supposedly user-friendly programs. If you observe an iPhone or Mac being used by someone who hasn t used one before it becomes obvious that they really aren t so user friendly and users need to memorise many operations. This is not a criticism of Apple, some tasks are inherently complex and require some complexity of the user interface. The limitations of the basic UI facilities become more obvious when there are operations like palm-swiping the screen for a screen-shot and a double-tap plus drag for a 1 finger zoom on Android. What else do we need to memorise?

12 September 2016

Steve Kemp: If your code accepts URIs as input..

There are many online sites that accept reading input from remote locations. For example a site might try to extract all the text from a webpage, or show you the HTTP-headers a given server sends back in response to a request. If you run such a site you must make sure you validate the schema you're given - also remembering to do that if you're sent any HTTP-redirects.
Really the issue here is a confusion between URL & URI.
The only time I ever communicated with Aaron Swartz was unfortunately after his death, because I didn't make the connection. I randomly stumbled upon the html2text software he put together, which had an online demo containing a form for entering a location. I tried the obvious input:
The software was vulnerable, read the file, and showed it to me. The site gives errors on all inputs now, so it cannot be used to demonstrate the problem, but on Friday I saw another site on Hacker News with the very same input-issue, and it reminded me that there's a very real class of security problems here. The site in question was and allows you to enter a URL to convert to markdown - I found this via the hacker news submission. The following link shows the contents of /etc/hosts, and demonstrates the problem: The output looked like this:
.. localhost broadcasthost
::1 localhost
fe80::1%lo0 localhost stage files brettt..
In the actual output of '/etc/passwd' all newlines had been stripped. (Which I now recognize as being an artifact of the markdown processing.) UPDATE: The problem is fixed now.

3 August 2016

John Goerzen: All Aboard

Aaaaaall Aboard! *chug* *chug* And so began a trip aboard our hotel train in Indianapolis, conducted by our very own Jacob and Oliver. IMG_20160703_101438 Because, well, what could be more fun than spending a few days in the world s only real Pullman sleeping car, on its original service track, inside a hotel? IMG_20160703_101520 We were on a family vacation to Indianapolis, staying in what two railfan boys were sure to enjoy: a hotel actually built into part of the historic Indianapolis Union Station complex. This is the original train track and trainshed. They moved in the Pullman cars, then built the hotel around them. Jacob and Oliver played for hours, acting as conductors and engineers, sending their train all across the country to pick up and drop off passengers. Opa! Have you ever seen a kid s face when you introduce them to something totally new, and they think it is really exciting, but a little scary too? That was Jacob and Oliver when I introduced them to saganaki (flaming cheese) at a Greek restaurant. The conversation went a little like this: Our waitress will bring out some cheese. And she will set it ON FIRE right by our table! Will it burn the ceiling? No, she ll be careful. Will it be a HUGE fire? About a medium-sized fire. Then what will happen? She ll yell OPA! and we ll eat the cheese after the fire goes out. Does it taste good? Oh yes. My favorite! It turned out several tables had ordered saganaki that evening, so whenever I saw it coming out, I d direct their attention to it. Jacob decided that everyone should call it opa instead of saganaki because that s what the waitstaff always said. Pretty soon whenever they d see something appear in the window from the kitchen, there d be craning necks and excited jabbering of maybe that s our opa! And when it finally WAS our opa , there were laughs of delight and I suspect they thought that was the best cheese ever. Giggling Elevators IMG_20160703_205544 Fun times were had pressing noses against the glass around the elevator. Laura and I sat on a nearby sofa while Jacob and Oliver sat by the elevators, anxiously waiting for someone to need to go up and down. They point and wave at elevators coming down, and when elevator passengers waved back, Oliver would burst out giggling and run over to Laura and me with excitement. Some history IMG_20160704_161550 We got to see the grand hall of Indianapolis Union Station what a treat to be able to set foot in this magnificent, historic space, the world s oldest union station. We even got to see the office where Thomas Edison worked, and as a hotel employee explained, was fired for doing too many experiments on the job. Water and walkways Indy has a system of elevated walkways spanning quite a section of downtown. It can be rather complex navigating them, and after our first day there, I offered to let Jacob and Oliver be the leaders. Boy did they take pride in that! They stopped to carefully study maps and signs, and proudly announced this way or turn here and were usually correct. 20160702_164754_Richtone(HDR) And it was the same in the paddleboat we took down the canal. Both boys wanted to be in charge of steering, and we only scared a few other paddleboaters. Fireworks IMG_20160704_220332 Our visit ended with the grand fireworks show downtown, set off from atop a skyscraper. I had been scouting for places to watch from, and figured that a bridge-walkway would be great. A couple other families had that thought too, and we all watched the 20-minute show in the drizzle. Loving brothers By far my favorite photo from the week is this one, of Jacob and Oliver asleep, snuggled up next to each other under the covers. They sure are loving and caring brothers, and had a great time playing together. IMG_20160702_071015

11 June 2016

Paul Tagliamonte: It's all relative

As nearly anyone who's worked with me will attest to, I've long since touted nedbat's talk Pragmatic Unicode, or, How do I stop the pain? as one of the most foundational talks, and required watching for all programmers. The reason is because netbat hits on something bigger - something more fundamental than how to handle Unicode -- it's how to handle data which is relative. For those who want the TL;DR, the argument is as follows: Facts of Life:
  1. Computers work with Bytes. Bytes go in, Bytes go out.
  2. The world needs more than 256 symbols.
  3. You need both Bytes and Unicode
  4. You cannot infer the encoding of bytes.
  5. Declared encodings can be Wrong
Now, to fix it, the following protips:
  1. Unicode sandwich
  2. Know what you have
  3. TEST
Relative Data I've started to think more about why we do the things we do when we write code, and one thing that continues to be a source of morbid schadenfreude is watching code break by failing to handle Unicode right. It's hard! However, watching what breaks lets you gain a bit of insight into how the author thinks, and what assumptions they make. When you send someone Unicode, there are a lot of assumptions that have to be made. Your computer has to trust what you (yes, you!) entered into your web browser, your web browser has to pass that on over the network (most of the time without encoding information), to a server which reads that bytestream, and makes a wild guess at what it should be. That server might save it to a database, and interpolate it into an HTML template in a different encoding (called Mojibake), resulting in a bad time for everyone involved. Everything's awful, and the fact our computers can continue to display text to us is a goddamn miracle. Never forget that. When it comes down to it, when I see a byte sitting on a page, I don't know (and can't know!) if it's Windows-1252, UTF-8, Latin-1, or EBCDIC. What's a poem to me is terminal garbage to you. Over the years, hacks have evolved. We have magic numbers, and plain ole' hacks to just guess based on the content. Of course, like all good computer programs, this has lead to its fair share of hilarious bugs, and there's nothing stopping files from (validly!) being multiple things at the same time. Like many things, it's all in the eye of the beholder. Timezones Just like Unicode, this is a word that can put your friendly neighborhood programmer into a series of profanity laden tirades. Go find one in the wild, and ask them about what they think about timezone handling bugs they've seen. I'll wait. Go ahead. Rants are funny things. They're fun to watch. Hilarious to give. Sometimes just getting it all out can help. They can tell you a lot about the true nature of problems. It's funny to consider the isomorphic nature of Unicode rants and Timezone rants. I don't think this is an accident. U n i c o d e timezone Sandwich Ned's Unicode Sandwich applies -- As early as we can, in the lowest level we can (reading from the database, filesystem, wherever!), all datetimes must be timezone qualified with their correct timezone. Always. If you mean UTC, say it's in UTC. Treat any unqualified datetimes as "bytes". They're not to be trusted. Never, never, never trust 'em. Don't process any datetimes until you're sure they're in the right timezone. This lets the delicious inside of your datetime sandwich handle timezones with grace, and finally, as late as you can, turn it back into bytes (if at all!). Treat locations as tzdb entries, and qualify datetime objects into their absolute timezone (EST, EDT, PST, PDT) It's not until you want to show the datetime to the user again should you consider how to re-encode your datetime to bytes. You should think about what flavor of bytes, what encoding -- what timezone -- should I be encoding into? TEST Just like Unicode, testing that your code works with datetimes is important. Every time I think about how to go about doing this, I think about that one time that mjg59 couldn't book a flight starting Tuesday from AKL, landing in HNL on Monday night, because United couldn't book the last leg to SFO. Do you ever assume dates only go forward as time goes on? Remember timezones. Construct test data, make sure someone in New Zealand's +13:45 can correctly talk with their friends in Baker Island's -12:00, and that the events sort right. Just because it's Noon on New Years Eve in England doesn't mean it's not 1 AM the next year in New Zealand. Places a few miles apart may go on Daylight savings different days. Indian Standard Time is not even aligned on the hour to GMT (+05:30)! Test early, and test often. Memorize a few timezones, and challenge your assumptions when writing code that has to do with time. Don't use wall clocks to mean monotonic time. Remember there's a whole world out there, and we only deal with part of it. It's also worth remembering, as Andrew Pendleton pointed out to me, that it's possible that a datetime isn't even unique for a place, since you can never know if 2016-11-06 01:00:00 in America/New_York (in the tzdb) is the first one, or second one. Storing EST or EDT along with your datetime may help, though! Pitfalls Improper handling of timezones can lead to some interesting things, and failing to be explicit (or at least, very rigid) in what you expect will lead to an unholy class of bugs we've all come to hate. At best, you have confused users doing math, at worst, someone misses a critical event, or our security code fails. I recently found what I regard to be a pretty bad bug in apt (which David has prepared a fix for and is pending upload, yay! Thank you!), which boiled down to documentation and code expecting datetimes in a timezone, but accepting any timezone, and silently treating it as UTC. The solution is to hard-fail, which is an interesting choice to me (as a vocal fan of timezone aware code), but at the least it won't fail by misunderstanding what the server is trying to communicate, and I do understand and empathize with the situation the apt maintainers are in. Final Thoughts Overall, my main point is although most modern developers know how to deal with Unicode pain, I think there is a more general lesson to learn -- namely, you should always know what data you have, and always remember what it is. Understand assumptions as early as you can, and always store them with the data.

5 June 2016

Petter Reinholdtsen: A program should be able to open its own files on Linux

Many years ago, when koffice was fresh and with few users, I decided to test its presentation tool when making the slides for a talk I was giving for NUUG on Japhar, a free Java virtual machine. I wrote the first draft of the slides, saved the result and went to bed the day before I would give the talk. The next day I took a plane to the location where the meeting should take place, and on the plane I started up koffice again to polish the talk a bit, only to discover that kpresenter refused to load its own data file. I cursed a bit and started making the slides again from memory, to have something to present when I arrived. I tested that the saved files could be loaded, and the day seemed to be rescued. I continued to polish the slides until I suddenly discovered that the saved file could no longer be loaded into kpresenter. In the end I had to rewrite the slides three times, condensing the content until the talk became shorter and shorter. After the talk I was able to pinpoint the problem kpresenter wrote inline images in a way itself could not understand. Eventually that bug was fixed and kpresenter ended up being a great program to make slides. The point I'm trying to make is that we expect a program to be able to load its own data files, and it is embarrassing to its developers if it can't. Did you ever experience a program failing to load its own data files from the desktop file browser? It is not a uncommon problem. A while back I discovered that the screencast recorder gtk-recordmydesktop would save an Ogg Theora video file the KDE file browser would refuse to open. No video player claimed to understand such file. I tracked down the cause being file --mime-type returning the application/ogg MIME type, which no video player I had installed listed as a MIME type they would understand. I asked for file to change its behavour and use the MIME type video/ogg instead. I also asked several video players to add video/ogg to their desktop files, to give the file browser an idea what to do about Ogg Theora files. After a while, the desktop file browsers in Debian started to handle the output from gtk-recordmydesktop properly. But history repeats itself. A few days ago I tested the music system Rosegarden again, and I discovered that the KDE and xfce file browsers did not know what to do with the Rosegarden project files (*.rg). I've reported the rosegarden problem to BTS and a fix is commited to git and will be included in the next upload. To increase the chance of me remembering how to fix the problem next time some program fail to load its files from the file browser, here are some notes on how to fix it. The file browsers in Debian in general operates on MIME types. There are two sources for the MIME type of a given file. The output from file --mime-type mentioned above, and the content of the shared MIME type registry (under /usr/share/mime/). The file MIME type is mapped to programs supporting the MIME type, and this information is collected from the desktop files available in /usr/share/applications/. If there is one desktop file claiming support for the MIME type of the file, it is activated when asking to open a given file. If there are more, one can normally select which one to use by right-clicking on the file and selecting the wanted one using 'Open with' or similar. In general this work well. But it depend on each program picking a good MIME type (preferably a MIME type registered with IANA), file and/or the shared MIME registry recognizing the file and the desktop file to list the MIME type in its list of supported MIME types. The /usr/share/mime/packages/rosegarden.xml entry for the Shared MIME database look like this:
<?xml version="1.0" encoding="UTF-8"?>
<mime-info xmlns="">
  <mime-type type="audio/x-rosegarden">
    <sub-class-of type="application/x-gzip"/>
    <comment>Rosegarden project file</comment>
    <glob pattern="*.rg"/>
This states that audio/x-rosegarden is a kind of application/x-gzip (it is a gzipped XML file). Note, it is much better to use an official MIME type registered with IANA than it is to make up ones own unofficial ones like the x-rosegarden type used by rosegarden. The desktop file of the rosegarden program failed to list audio/x-rosegarden in its list of supported MIME types, causing the file browsers to have no idea what to do with *.rg files:
% grep Mime /usr/share/applications/rosegarden.desktop
The fix was to add "audio/x-rosegarden;" at the end of the MimeType= line. If you run into a file which fail to open the correct program when selected from the file browser, please check out the output from file --mime-type for the file, ensure the file ending and MIME type is registered somewhere under /usr/share/mime/ and check that some desktop file under /usr/share/applications/ is claiming support for this MIME type. If not, please report a bug to have it fixed. :)

3 June 2016

Gunnar Wolf: Stop it with those short PGP key IDs!

Debian is quite probably the project that most uses a OpenPGP implementation (that is, GnuPG, or gpg) for many of its internal operations, and that places most trust in it. PGP is also very widely used, of course, in many other projects and between individuals. It is regarded as a secure way to do all sorts of crypto (mainly, encrypting/decrypting private stuff, signing public stuff, certifying other people's identities). PGP's lineage traces back to Phil Zimmerman's program, first published in 1991 By far, not a newcomer PGP is secure, as it was 25 years ago. However, some uses of it might not be so. We went through several migrations related to algorithmic weaknesses (i.e. v3 keys using MD5; SHA1 is strongly discouraged, although not yet completely broken, and it should be avoided as well) or to computational complexity (as the migration away from keys smaller than 2048 bits, strongly prefering 4096 bits). But some vulnerabilities are human usage (that is, configuration-) related. Today, Enrico Zini gave us a heads-up in the #debian-keyring IRC channel, and started a thread in the debian-private mailing list; I understand the mail to a private list was partly meant to get our collective attention, and to allow for potentially security-relevant information to be shared. I won't go into details about what is, is not, should be or should not be private, but I'll post here only what's public information already. What are short and long key IDs? I'll start by quoting Enrico's mail:
there are currently at least 3 ways to refer to a gpg key: short key ID (last 8 hex digits of fingerprint), long key ID (last 16 hex digits) and full fingerprint. The short key ID used to be popular, and since 5 years it is known that it is computationally easy to generate a gnupg key with an arbitrary short key id. A mitigation to this is using "keyid-format long" in gpg.conf, and a better thing to do, especially in scripts, is to use the full fingerprint to refer to a key, or just ship the public key for verification and skip the key servers. Note that in case of keyid collision, gpg will download and import all the matching keys, and will use all the matching keys for verifying signatures.
So... What is this about? We humans are quite bad at recognizing and remembering randomly-generated strings with no inherent patterns in them. Every GPG key can be uniquely identified by its fingerprint, a 128-bit string, usually encoded as ten blocks of four hexadecimal characters (this allows for 160 bits; I guess there's space for a checksum in it). That is, my (full) key's signature is:
AB41 C1C6 8AFD 668C A045  EBF8 673A 03E4 C1DB 921F
However, it's quite hard to recognize such a long string, let alone memorize it! So, we often do what humans do: Given that strong cryptography implies a homogenous probability distribution, people compromised on using just a portion of the key the last portion. The short key ID. Mine is then the last two blocks (shown in boldface): C1DB921F. We can also use what's known as the long key ID, that's twice as long: 64 bits. However, while I can speak my short key ID on a single breath (and maybe even expect you to remember and note it down), try doing so with the long one (shown in italics above): 673A03E4C1DB921F. Nah. Too much for our little, analog brains. This short and almost-rememberable number has then 32 bits of entropy I have less than one in 4,000,000,000 chance of generating a new key with this same short key ID. Besides, key generation is a CPU-intensive operation, so it's quite unlikely we will have a collision, right? Well, wrong. Previous successful attacks on short key IDs Already five years ago, Asheesh Laroia migrated his 1024D key to a 4096R. And, as he describes in his always-entertaining fashion, he made his computer sweat until he was able to create a new key for which the short key ID collided with the old one. It might not seem like a big deal, as he did this non-maliciously, but this easily should have spelt game over for the usage of short key IDs. After all, being able to generate a collision is usually the end for cryptographic systems. Asheesh specifically mentioned in his posting how this could be abused. But we didn't listen. Short key IDs are just too convenient! Besides, they allow us to have fun, can be a means of expression! I know of at least two keys that would qualify as vanity: Obey Arthur Liu's 0x29C0FFEE (created in 2009) and Keith Packard's 0x00000011 (created in 2012). Then we got the Evil 32 project. They developed Scallion, started (AFAICT) in 2012. Scallion automates the search for a 32-bit collision using GPUs; they claim that it takes only four seconds to find a collision. So, they went through the strong set of the public PGP Web of Trust, and created a (32-bit-)colliding key for each of the existing keys. And what happened now? What happened today? We still don't really know, but it seems we found a first potentially malicious collision that is, the first "nonacademic" case. Enrico found two keys sharing the 9F6C6333 short ID, apparently belonging to the same person (as would be the case of Asheesh, mentioned above). After contacting Gustavo, though, he does not know about the second That is, it can be clearly regarded as an impersonation attempt. Besides, what gave away this attempt are the signatures it has: Both keys are signed by what appears to be the same three keys: B29B232A, F2C850CA and 789038F2. Those three keys are not (yet?) uploaded to the keyservers, though... But we can expect them to appear at any point in the future. We don't know who is behind this, or what his purpose is. We just know this looks very evil. Now, don't panic: Gustavo's key is safe. Same for his certifiers, Marga, Agust n and Maxy. It's just a 32-bit collision. So, in principle, the only parties that could be cheated to trust the attacker are humans, right? Nope. Enrico tested on the PGP pathfinder & key statistics service, a keyserver that finds trust paths between any two arbitrary keys in the strong set. Surprise: The pathfinder works on the short key IDs, even when supplied full fingerprints. So, it turns out I have three faked trust paths into our impostor. What next? There are several things this should urge us to do. And there are surely many other important recommendations. But this is a good set of points to start with. [update] I was pointed at Daniel Kahn Gillmor's 2013 blog post, OpenPGP Key IDs are not useful. Daniel argues, in short, that cutting a fingerprint in order to get a (32- or 64-bit) short key ID is the worst of all worlds, and we should rather target either always showing full fingerprints, or not showing it at all (and leaving all the crypto-checking bits to be done by the software, as comparing 160-bit strings is not natural for us humans). [update] This post was picked up by A very interesting discussion continues in their comments.

25 April 2016

Gunnar Wolf: Passover / Pesaj, a secular viewpoint, a different viewpoint... And slowly becoming history!

As many of you know (where "you" is "people reading this who actually know who I am), I come from a secular Jewish family. Although we have some religious (even very religious) relatives, neither my parents nor my grandparents were religious ever. Not that spirituality wasn't important to them My grandparents both went deep into understanding by and for themselves the different spiritual issues that came to their mind, and that's one of the traits I most remember about them while I was growing up. But formal, organized religion was never much welcome in the family; again, each of us had their own ways to concile our needs and fears with what we thought, read and understood. This week is the Jewish celebration of Passover, or Pesaj as we call it (for which Passover is a direct translation, as Pesaj refers to the act of the angel of death passing over the houses of the sons of Israel during the tenth plague in Egypt; in Spanish, the name would be Pascua, which rather refers to the ritual sacrifice of a lamb that was done in the days of the great temple)... Anyway, I like giving context to what I write, but it always takes me off the main topic I want to share. Back to my family. I am a third-generation member of the Hashomer Hatzair zionist socialist youth movement; my grandmother was among the early Hashomer Hatzair members in Poland in the 1920s, both my parents were active in the Mexico ken in the 1950s-1960s (in fact, they met and first interacted there), and I was a member from 1984 until 1996. It was also thanks to Hashomer that my wife and I met, and if my children get to have any kind of Jewish contact in their lifes, I hope it will be through Hashomer as well. Hashomer is a secular, nationalist movement. A youth movement with over a century of history might seem like a contradiction. Over the years, of course, it has changed many details, but as far as I know, the essence is still there, and I hope it will continue to be so for good: Helping shape integral people, with identification with Judaism as a nation and not as a religion; keeping our cultural traits, but interpreting them liberally, and aligned with a view towards the common good Socialism, no matter how the concept seems pass nowadays. Colectivism. Inclusion. Peaceful coexistence with our neighbours. Acceptance of the different. I could write pages on how I learnt about each of them during my years in Hashomer, how such concepts striked me as completely different as what the broader Jewish community I grew up in understood and related to them... But again, I am steering off the topic I want to pursue. Every year, we used to have a third Seder (that is, a third Passover ceremony) at Hashomer. A third one, because as tradition mandates two ceremonies to be held outside Israel, and a movement comprised of people aged between 7 and 21, having a seder competing with the familiar one would not be too successful, we held a celebration on a following day. But it would never be the same as the "formal" Pesaj: For the Seder, the Jewish tradition mandates following the Hagada The Seder always follows a predetermined order (literally, Seder means order), and the Hagad (which means both legend and a story that is spoken; you can find full Hagadot online if you want to see what rites are followed; I found a seemingly well done, modern, Hebrew and English version, a more traditional one, in Hebrew and Spanish, and Wikipedia has a description including its parts and rites) is, quite understandably, full with religious words, praises for God, and... Well, many things that are not in line with Hashomer's values. How could we be a secular movement and have a big celebration full with praises for God? How could we yearn for life in the kibbutz distance from the true agricultural meaning of the celebration? The members of Hashomer Hatzair repeatedly took on the task (or, as many would see it, the heresy) of adapting the Hagada to follow their worldview, updated it for the twentieth century, had it more palatable for our peculiarities. Yesterday, when we had our Seder, I saw my father still has together with the other, more traditional Hagadot we use two copies of the Hagad he used at Hashomer Hatzair's third Seder. And they are not only beautiful works showing what they, as very young activists thought and made solemn, but over time, they are becoming historic items by themselves (one when my parents were still young janijim, in 1956, and one when they were starting to have responsabilities and were non-formal teachers or path-showers, madrijim, in 1959). He also had a copy of the Hagad we used in the 1980s when I was at Hashomer; this last one was (sadly?) not done by us as members of Hashomer, but prepared by a larger group between Hashomer Hatzair and the Mexican friends of Israeli's associated left wing party, Mapam. This last one, I don't know which year it was prepared and published on, but I remember following it in our ceremony. So, I asked him to borrow me the three little books, almost leaflets, and scanned them to be put online. Of course, there is no formal licensing information in them, much less explicit authorship information, but they are meant to be shared So I took the liberty of uploading them to the Internet Archive, tagging them as CC-0 licensed. And if you are interested in them, flowing over and back between Spanish and Hebrew, with many beautiful texts adapted for them from various sources, illustrated by our own with the usual heroic, socialist-inspired style, and lovingly hand-reproduced using the adequate technology for their day... Here they are: I really enjoyed the time I took scanning and forming them, reading some passages, imagining ourselves and my parents as youngsters, remembering the beautiful work we did at such a great organization. I hope this brings this joy to others like it did to me. , . Once shomer, always shomer.

4 March 2016

Enrico Zini: Praise of component reuse

I farm bits and pieces out to the guys who are much more brilliant than I am. I say, "build me a laser", this. "Design me a molecular analyzer", that. They do, and I just stick 'em together. (Seth Brundle, "The Fly")
When I decided to try and turn siterefactor into staticsite, I decided that I would go ahead only for as long as it could be done with minimal work, writing code in the most straightforward way on top of existing and stable components. I am pleased by how far that went. Python-Markdown It works fast enough, already comes with extensions for most of what I needed, and can be extended in several ways. One of the extension methods is a hook for manipulating the ElementTree of the rendered document before serializing it to HTML, which made it really easy to go and process internal links in all <a href= and <img src= attributes. To tell an internal link from an external link I just use the standard python urlparse and see if the link has a scheme or a netloc component. If it does not, and if it has a path, then it is an internal link. This also means that I do not need to invent new Markdown syntax for internal references, avoiding the need for remembering things like [text]( < relref "blog/" > ) or [text]( filename /blog/ In staticsite, it's just [text](/blog/ or [text]( if the post is nearby. This feels nicely clean to me: if I wanted to implement fancy markdown features, I could do it as Python-Markdown extensions and submit them upstream. If I wanted to implement fancy interlinking features, I could do it with a special url scheme in links. For example, it would be straigtforward to implement a ssite: url scheme that expanded the url with elements from staticsite's settings using a call to python's string.format (ssite: SETTING_NAME /bar maybe?), except I do not currently see any use cases for extending internal linking from what it is now. Jinja2 Jina2 is a template engine that I already knew, it is widely used, powerful and pleasant to use, both on the templating side and on the API's side. It is not HTML specific, so I can also use it to generate Atom, RSS2, "dynamic" site content, and even new site Markdown pages. Implementing RSS and Atom feeds was just a matter of writing and testing these Jinja2 macros and then reusing them anywhere. toml, yaml, json No need to implement my own front matter parsing. Also, reusing the same syntax as Hugo allows me to just link to its documentation. python-slugify I found python-slugify so I did not bother writing a slug-generating function. As a side effect, now things works better than I would even have thought to implement, including transliteration of non-ascii characters:
$ ./ssite new example --noedit --title "Cos  parl  Enrico"
(I just filed an RFP) python-livereload Implementing ssite serve which monitors the file system and autoreloads when content changes and renders everything on the fly, took about an hour. Most of that hour went into implementing rendering pages on demand. Then I discovered that it autoreloads even when I edit staticsite's source code. Then I discovered that it communicates with the browser and even automatically triggers a page refresh. I can keep vim on half my screen and a browser in the other half, and I get live preview for free every time I save, without ever leaving the editor. Bootstrap I already use Bootstrap at work, so creating the default theme templates with it took about 10 minutes. This morning I tried looking at my website using my mobile phone, and I pleasantly saw it automatically turning into a working mobile version of itself. Pygments Python-Markdown uses Pygments for syntax highlighting, and it can be themed just by loading a .css. So, without me really doing anything, even staticsite's syntax highligthing is themable, and there's even a nice page with a list of themes to choose from. Everything else... Command line parsing? Straight argparse. Logging? python's logging support. Copying static resource files? shutil.copy2. Parsing dates? dateutil.parser. Timing execution? time.perf_counter. Timezone handling? pytz. Building the command to run an editor? string.format. Matching site pages? fnmatch.translate. ...and then some. If I ever decide to implement incremental rendering, how do I implement tracking which source files have changed? Well, for example, how about just asking git?

24 February 2016

Norbert Preining: Switching from iOS to Android

This article starts a series of blogs on my ventures into Android land after having used iOS devices for 6 years. I have never been a strong believer in the Apple ecosystem, and my trials to convince myself to MacBooks and MacPros always ended with installing Linux on them, so I guess I wasn t really the ideal target for iOS. Thus, my iOS devices were also permanently in jailbroken state, otherwise I would feel amputated. But as much as I disliked the lock-in and closed environment of the iOS world, it was from the user perspective surprisingly well done and smooth. So it was with a certain level of tension when I finally switched to Linux^WAndroid. android-ios If you don t want to read on, here the preliminary conclusion: Why didn t I do it earlier! But before we go into details, let me start with my background: History of my devices Originally I was a big opponent of smart phones and preferred the Unix-way, one device for one thing. So I had a normal phone and (various) Palm devices (Tungsten X, Tungsten C, and above all my beloved Handera TRGpro). I loved the Palm world and considered it superior to the then smart phone world, until I came to Japan, where the challenge of a proper input method for Japanese and proper Japanese support posed a big hurdle. The Palm devices had a stick and written input fields, but Japanese input was practically impossible and a huge pain. Searching for a word in Japanese was more hurdle then looking it up in a printed dictionary. In addition, I needed a phone in Japan, so I plunged into the smart phone world and got myself a iPhone (3g). What a world did open for me: easy typing of Japanese, dictionaries, on-the-fly translation, woooow! And above all, I discovered my most beloved and till now one of my most important programs: Flashcards Deluxe. Thanks, and I have to say to 80% thanks to this program my Japanese learning speed has accelerated considerably. There is nothing more important for me than getting drilled in a systematic way. But I derail, anyway, having Flashcard Deluxe on the iPhone within rather short time I had about 10000 or more flashcards created, and moving on to a different architecture (Android) was for quite some time practically impossible without loosing years of statistics and learning, so I renewed my contract after 2 years together with a iPhone 4s. Another two years passed, and these years brought an Android version of Flashcards Deluxe, as well as Dropbox syncing, so I had no excuse anymore to remain in iOS land, wouldn t it be for an iPhone 5s that was passed to me near the end of my forth year, so I again extended the contract for two years. Finally, after 6 years of iPhone devices, this January I finally decided it is time to switch to Android. After lots of thinking, comparing, and requesting advice from good friends with more experience in the smart phone market I went for a Google Nexus 6p. Google Nexus 6p I will not repeat the specs of this phone as they are widely available on the net. My original plan was a Samsung S6, but after consultation with an expert I decided for an original Google phone for better security support. That left me with the option between a Nexus 5x and 6p, and due to prize differences (prizes of mobiles are ridiculously strange in Japan) I went for the 6p instead of the 5x. One point that made the decision for this slight too big device easy was the fact that it uses a great AMOLED display. Moving the data Since I was using Google Calendar and Google Contacts already on the iPhone, moving to the Android phone was far less a hassle than I thought. My contacts and events showed up without a hiccup. Most of the usual apps are nowadays available on both iOS and Android, so the most difficult thing was remembering all the passwords to log into the applications again (SNS like G+, FB, Twitter etc). The same is more or less true for messengers of all kinds (Line, WhatsApp, Threema, etc), but here one is advised to check with the respective web site first to make sure one does not loose all of the important data. Line for example is a stupid ***** that deletes all previous chats on the old phone and does not make them available on the new one. WhatsApp can be converted with a special conversion program. Threema, too allows for transfer of ids. Move of applications After that came the hunt for replacement applications for those that are not available as is on Android: Mail At first like probably everyone I used the shipped GMail program. It might be good for Google Mail accounts, but for anything else it is just a real pain. Thus, I have searched a bit and finally settled (for now) for K-9 Mail: it is open source, open development, feature rich, and more a hackers type email program, perfectly suited to me. There is a commercial variant called K@-Mail that says that it improves the user interface and some usability items as well as features, but I didn t see much of an advantage over the original version (which is completely free) and in fact some of my accounts didn t work at all. So I remain with K9 Mail and I think this is a good decision. Calendar Managing Calendars is one of the most important task for me. I have been a fervent supporter of DateBk4, DateBk 5, and DateBk 6 on the original Palm series, and when I left the Palm World it was with great pain that I had to loose DateBk. Not only because it was a simply fantastic calendar program that allowed me to keep track of all my climbing routes, festivities, in a much more advanced way than any other Calendering application, but also because the programmer of the DateBk series is running the Dewar Wildlife Trust, a Gorilla rescue group and a lot of the money he makes from the app sales is going to rescue Gorillas. With the switch to iOS this option was gone, and I first used the built-in calendar application (which is so weak) and later and for long time Pocket Informant Pro. This is a very good program and probably the only one that can compete with DateBk with respect to functionality and usefulness. During the time of me being locked in in iOS I realized that the world has moved on and a new version of DateBk series for Java was developed, called Pimlical. First only available on Windows, it became later available also on Android and Linux, too. The following screen shot puts Pimlical on the left, and Pocket Informant on the right. I will write a more detailed comparison in future, in short: PInformant is more streamlined and polished, Pimlical has more configuration option. Practically everything can be adjusted to one s need, and in addition there is also a Desktop application that sync either with Google and the phone, or only with the phone if you want to live off the grid. pimlical-pinformant So nowadays on Android I have both Pocket Informant Pro as well as Pimlical, but after a short time I have now switched practically exclusively to Pimlical. Notes Here there is pain HUGE PAIN!!! iOS has an excellent applications for notes, called simply Notebooks. This little pearl was my work horse for everything (more or less) memorable. From poems and song texts to bus time tables, from PDF to GIFs, from MarkDown to HTML, everything could be saved into Notebooks, displayed, edited, ordered. And above all it had automatic background sync with Dropbox. So I could drop new files into the respective sub-folder of my Dropbox folder and could be sure I have the files available on my phone when I leave for a trip. And there is a huge bag of features that I haven t even tapped into! Android is unfortunately not on the list of supported architectures of Notebooks. So I searched far and wide, and without any success. There are all kind of notes, flash colors, overly simple, fast and slow, stylish and plain, but none of them did even provide half of the features of Notebooks. None, not even half. I still hope I might find the ultimate notes application, or even better would be an Android version of the original Notebooks application (but this is not high on the developers todo list), but for now I am in despair The Rest As I said, most apps are nowadays available on both platforms, so there is not much more to do than download the respective Android app and log in again. That worked very nice across practically all apps. Things I don t like (i.e., which are broken!) on Android Although a very convenient system and perfectly made to fit my taste, there are some things that are a huge pain (and a big shame on Google to not being able to fix that for long time!): Japanese fonts when the device is in English interface language In case you are a foreigner living in Japan and want your Android phone in English, but still read emails, news, etc in Japanese, then Android provides you with the worst, namely Chinese fonts: chinese-japanese-mix This is a well known problem and I have blogged about fixing the very same problem on Linux (Debian), and the solution is a simple reshuffling in the fontconfig configuration files. There is even an application for it in the Google store, Kanji Fix, but it needs a rooted device (which I haven t done till now my failure!). I can only hope that Google fixes this completely stupid problem in a future version. The Me problem Another of these beasty problems: The Android Contacts application has an entry for Me , which unfortunately, no idea why, cannot be linked with my normal me in the list of contacts. There are reports all over the Internet, strange suggestions, and no real solution. Again, a simple thing that should work but doesn t. Invisible Images folder in MTP mode A more annoying problem is that the camera folder under Photos does not show up when connecting the device in MTP mode to my computer, and as consequence me being unable to copy photos from the device to my computer. The solution I am using at the moment is moving the photos with a file manager to a new folder which is visible during MTP communcation, and copy the photos from there. But this, too, should be something trivial, but alas, despite a lot of posts on the internet I couldn t find a proper solution. Google Music As written somewhere else, Google Music has switched from 5 star system to up/down system, which is a huge pain and PITA. Things I do like (or I discovered) on Android There are some things I haven t been used/tried on iOS they might be possible which I really like: Yubikey Neo support I will write about this in a different blog, but nowadays I have my GPG keys on an hardware token (Yubikey Neo) and the application OpenKeychain on Android works nicely with both K9 Mail and via NFC with my Yubikey. That is a great tool! Bluetooth streaming Bluetooth on iOS devices was always a bit broken for me, so connecting my phone to my old car radio I needed radio transmitter that was connected to the cable port of the iPhone. With Android I use a Bluetooth Radio device (receives data via bluetooth, and sends music out via radio waves for a car stereo to receive them). Now if my monthly data limit wouldn t be that low  Debian on Android Yes, you can have a full Debian system running in your terminal on Android. There are several applications providing this feature, and I am rather surprised how smooth it works. Conclusion My preliminary conclusion is that the switch to Android at this time was perfectly timed, and from the technological side I should have done much earlier. In future blogs I will discuss particular instances of this transition in more details. If you have any suggestion for me, in particular for a good notes taking application, please let me know!

21 January 2016

Russell Coker: Finding Storage Performance Problems

Here are some basic things to do when debugging storage performance problems on Linux. It s deliberately not an advanced guide, I might write about more advanced things in a later post. Disk Errors When a hard drive is failing it often has to read sectors several times to get the right data, this can dramatically reduce performance. As most hard drives aren t monitored properly (email or SMS alerts on errors) it s quite common for the first notification about an impending failure to be user complaints about performance. View your kernel message log with the dmesg command and look in /var/log/kern.log (or wherever your system is configured to store kernel logs) for messages about disk read errors, bus resetting, and anything else unusual related to the drives. If you use an advanced filesystem like BTRFS or ZFS there are system commands to get filesystem information about errors. For BTRFS you can run btrfs device stats MOUNTPOINT and for ZFS you can run zpool status . Most performance problems aren t caused by failing drives, but it s a good idea to eliminate that possibility before you continue your investigation. One other thing to look out for is a RAID array where one disk is noticeably slower than the others. For example if you have a RAID-5 or RAID-6 array every drive should have almost the same number of reads and writes, if one disk in the array is at 99% performance capacity and the other disks are at 5% then it s an indication of a failing disk. This can happen even if SMART etc don t report errors. Monitoring IO The iostat program in the Debian sysstat package tells you how much IO is going to each disk. If you have physical hard drives sda, sdb, and sdc you could run the command iostat -x 10 sda sdb sdc to tell you how much IO is going to each disk over 10 second periods. You can choose various durations but I find that 10 seconds is long enough to give results that are useful. By default iostat will give stats on all block devices including LVM volumes, but that usually gives too much data to analyse easily. The most useful things that iostat tells you are the %util (the percentage utilisation anything over 90% is a serious problem), the reads per second r/s , and the writes per second w/s . The parameters to iostat for block devices can be hard drives, partitions, LVM volumes, encrypted devices, or any other type of block device. After you have discovered which block devices are nearing their maximum load you can discover which of the partitions, RAID arrays, or swap devices on that disk are causing the load in question. The iotop program in Debian (package iotop) gives a display that s similar to that of top but for disk io. It generally isn t essential (you can run ps ax grep D to get most of that information), but it is handy. It will tell you which programs are causing IO on a busy filesystem. This can be good when you have a busy system and don t know why. It isn t very useful if you have a system that is used for one task, EG a database server that is known to be busy doing database stuff. It s generally a good idea to have sysstat and iotop installed on all systems. If a system is experiencing severe performance problems you might not want to wait for new packages to be installed. In Debian the sysstat package includes the sar utility which can give historical information on system load. One benefit of using sar for diagnosing performance problems is that it shows you the time of day that has the most load which is the easiest time to diagnose performance problems. Swap Use Swap use sometimes confuses people. In many cases swap use decreases overall disk use, this is the design of the Linux paging algorithms. So if you have a server that accesses a lot of data it might swap out some unused programs to make more space for cache. When you have multiple virtual machines on one system sharing the same disks it can be difficult to determine the best allocation for RAM. If one VM has some applications allocating a lot of RAM but not using it much then it might be best to give it less RAM and force those applications into swap so that another VM can cache all the data it accesses a lot. The important thing is not the amount of swap that is allocated but the amount of IO that goes to the swap partition. Any significant amount of disk IO going to a swap device is a serious problem that can be solved by adding more RAM. Reads vs Writes The ratio of reads to writes depends on the applications and the amount of RAM. Some applications can have most of their reads satisfied from cache. For example an ideal configuration of a mail server will have writes significantly outnumber reads (I ve seen ratios of 5:1 for writes to reads on real mail servers). Ideally a mail server will cache all new mail for at least an hour and as the most prolific users check their mail more frequently than that most mail will be downloaded before it leaves the cache. If you have a mail server with reads outnumbering writes then it needs more RAM. RAM is cheap nowadays so if you don t want to compete with Gmail it should be cheap to buy enough RAM to cache all recent mail. The ratio of reads to writes is important because it s one way of quickly determining if you have enough RAM and adding RAM is often the cheapest way of improving performance. Unbalanced IO One common performance problem on systems with multiple disks is having more load going to some disks than to others. This might not be a problem (EG having cron jobs run on disks that are under heavy load while the web server accesses data from lightly loaded disks). But you need to consider whether it s desirable to have some disks under more load than others. The simplest solution to this problem is to just have a single RAID array for all data storage. This is also the solution that gives you the maximum available disk space if you use RAID-5 or RAID-6. A more complex option is to use some SSDs for things that require performance and disks for things that don t. This can be done with the ZIL and L2ARC features of ZFS or by just creating a filesystem on SSD for the data that is most frequently accessed. What Did I Miss? I m sure that I missed something, please let me know of any other basic things to do or suggestions for a post on more advanced things.

4 January 2016

John Goerzen: Hiking a mountain with Ian Murdock

Would you like to hike a mountain? That question caught me by surprise. It was early in 2000, and I had flown to Tucson for a job interview. Ian Murdock was starting a new company, Progeny, and I was being interviewed for their first hire. Well, I thought, hiking will be fun. So we rode a bus or something to the top of the mountain and then hiked down. Our hike was full of well, everything. Ian talked about Tucson and the mountains, about his time as the Debian project leader, about his college days. I asked about the plants and such we were walking past. We talked about the plans for Progeny, my background, how I might fit in. It was part interview, part hike, part two geeks chatting. Ian had no HR telling him you can t go hiking down a mountain with a job candidate, as I m sure HR would have. And I am glad of it, because even 16 years later, that is still by far the best time I ever had at a job interview, despite the fact that it ruined the only pair of shoes I had brought along I had foolishly brought dress shoes for a, well, job interview. I guess it worked, too, because I was hired. Ian wanted to start up the company in Indianapolis, so over the next little while there was the busy work of moving myself and setting up an office. I remember those early days Ian and I went computer shopping at a local shop more than once to get the first workstations and servers for the company. Somehow he had found a deal on some office space in a high-rent office building. I still remember the puzzlement on the faces of accountants and lawyers dressed up in suits riding in the elevators with us in our shorts and sandals, or tie-die, next to them. Progeny s story was to be a complicated one. We set out to rock the world. We didn t. We didn t set out to make lasting friendships, but we often did. We set out to accomplish great things, and we did some of that, too. We experienced a full range of emotions there elation when we got hardware auto-detection working well or when our downloads looked very popular, despair when our funding didn t come through as we had hoped, being lost when our strategy had to change multiple times. And, as is the case everywhere, none of us were perfect. I still remember the excitement after we published our first release on the Internet. Our little server that could got pegged at 100Mb of outbound bandwidth (that was something for a small company in those days.) The moment must have meant something, because I still have the mrtg chart from that day on my computer, 15 years later. Progeny's Bandwidth Chart We made a good Linux distribution, an excellent Debian derivative, but commercial success did not flow from it. In the succeeding months, Ian and the company tried hard to find a strategy that would stick and make our big break. But that never happened. We had several rounds of layoffs when hoped-for funding never materialized. Ian eventually lost control of the company, and despite a few years of Itanium contract work after I left, closed for good. Looking back, Progeny was life compressed. During the good times, we had joy, sense of accomplishment, a sense of purpose at doing something well that was worth doing. I had what was my dream job back then: working on Debian as I loved to do, making the world a better place through Free Software, and getting paid to do it. And during the bad times, different people at Progeny experienced anger, cynicism, apathy, sorrow for the loss of our friends or plans, or simply a feeling to soldier on. All of the emotions, good or bad, were warranted in their own way. Bruce Byfield, one of my co-workers at Progeny, recently wrote a wonderful memoriam of Ian. He wrote, More than anything, he wanted to repeat his accomplishment with Debian, and, naturally he wondered if he could live up to his own expectations of himself. That, I think, was Ian s personal tragedy that he had succeeded early in life, and nothing else he did with his life could quite measure up to his expectations and memories. Ian was not the only one to have some guilt over Progeny. I, for years, wondered if I should have done more for the company, could have saved things by doing something more, or different. But I always came back to the conclusion I had at the time: that there was nothing I could do a terribly sad realization. In the years since, I watched Ubuntu take the mantle of easy-to-install Debian derivative. I saw them reprise some of the ideas we had, and even some of our mistakes. But by that time, Progeny was so thoroughly forgotten that I doubt they even realized they were doing it. I had long looked at our work at Progeny as a failure. Our main goal was never accomplished, our big product never sold many copies, our company eventually shuttered, our rock-the-world plan crumpled and forgotten. And by those traditional measurements, you could say it was a failure. But I have come to learn in the years since that success is a lot more that those things. Success is also about finding meaning and purpose through our work. As a programmer, success is nailing that algorithm that lets the application scale 10x more than before, or solving that difficult problem. As a manager, success is helping team members thrive, watching pieces come together on projects that no one person could ever do themselves. And as a person, success comes from learning from our experiences, and especially our mistakes. As J. Michael Straczynski wrote in a Babylon 5 episode, loosely paraphrased: Maybe this experience will be a good lesson. Too bad it was so painful, but there ain t no other kind. The thing about Progeny is this Ian built a group of people that wanted to change the world for the better. We gave it our all. And there s nothing wrong with that. Progeny did change the world. As us Progeny alumni have scattered around the country, we benefit from the lessons we learned there. And many of us were different , sort of out of place before Progeny, and there we found others that loved C compilers, bootloaders, and GPL licenses just as much as we did. We belonged, not just online but in life, and we went on to pull confidence and skill out of our experience at Progeny and use them in all sorts of ways over the years. And so did Ian. Who could have imagined the founder of Debian and Progeny would one day lead the cause of an old-guard Unix turning Open Source? I run ZFS on my Debian system today, and Ian is partly responsible for that and his time at Progeny is too. So I can remember Ian, and Progeny, as a success. And I leave you with a photo of my best memento from the time there: an original unopened boxed copy of Progeny Linux. IMG_6197_v1

2 January 2016

Daniel Pocock: The great life of Ian Murdock and police brutality in context

Tributes: (You can Follow or Tweet about this blog on Twitter) Over the last week, people have been saying a lot about the wonderful life of Ian Murdock and his contributions to Debian and the world of free software. According to one news site, a San Francisco police officer, Grace Gatpandan, has been doing the opposite, starting a PR spin operation, leaking snippets of information about what may have happened during Ian's final 24 hours. Sadly, these things are now starting to be regurgitated without proper scrutiny by the mainstream press (note the erroneous reference to SFGate with link to, this is British tabloid media at its best). The report talks about somebody (no suggestion that it was even Ian) "trying to break into a residence". Let's translate that from the spin-doctor-speak back to English: it is the silly season, when many people have a couple of extra drinks and do silly things like losing their keys. "a residence", or just their own home perhaps? Maybe some AirBNB guest arriving late to the irritation of annoyed neighbours? Doesn't the choice of words make the motive sound so much more sinister? Nobody knows the full story and nobody knows if this was Ian, so snippets of information like this are inappropriate, especially when somebody is deceased. Did they really mean to leave people with the impression that one of the greatest visionaries of the Linux world was also a cat burglar? That somebody who spent his life giving selflessly and generously for the benefit of the whole world (his legacy is far greater than Steve Jobs, as Debian comes with no strings attached) spends the Christmas weekend taking things from other people's houses in the dark of the night? The report doesn't mention any evidence of a break-in or any charges for breaking-in. If having a few drinks and losing your keys in December is such a sorry state to be in, many of us could potentially be framed in the same terms at some point in our lives. That is one of the reasons I feel so compelled to write this: somebody else could be going through exactly the same experience at the moment you are reading this. Any of us could end up facing an assault as unpleasant as the tweets imply at some point in the future. At least I can console myself that as a privileged white male, the risk to myself is much lower than for those with mental illness, the homeless, transgender, Muslim or black people but as the tweets suggest, it could be any of us. The story reports that officers didn't actually come across Ian breaking in to anything, they encountered him at a nearby street corner. If he had weapons or drugs or he was known to police that would have almost certainly been emphasized. Is it right to rush in and deprive somebody of their liberties without first giving them an opportunity to identify themselves and possibly confirm if they had a reason to be there? The report goes on, "he was belligerent", "he became violent", "banging his head" all by himself. How often do you see intelligent and successful people like Ian Murdock spontaneously harming themselves in that way? Can you find anything like that in any of the 4,390 Ian Murdock videos on YouTube? How much more frequently do you see reports that somebody "banged their head", all by themselves of course, during some encounter with law enforcement? Do police never make mistakes like other human beings? If any person was genuinely trying to spontaneously inflict a head injury on himself, as the police have suggested, why wouldn't the police leave them in the hospital or other suitable care? Do they really think that when people are displaying signs of self-harm, rounding them up and taking them to jail will be in their best interests? Now, I'm not suggesting this started out with some sort of conspiracy. Police may have been at the end of a long shift (and it is a disgrace that many US police are not paid for their overtime) or just had a rough experience with somebody far more sinister. On the other hand, there may have been a mistake, gaps in police training or an inappropriate use of a procedure that is not always justified, like a strip search, that causes profound suffering for many victims. A select number of US police forces have been shamed around the world for a series of incidents of extreme violence in recent times, including the death of Michael Brown in Ferguson, shooting Walter Scott in the back, death of Freddie Gray in Baltimore and the attempts of Chicago's police to run an on-shore version of Guantanamo Bay. Beyond those highly violent incidents, the world has also seen the abuse of Ahmed Mohamed, the Muslim schoolboy arrested for his interest in electronics and in 2013, the suicide of Aaron Swartz which appears to be a direct consequence of the "Justice" department's obsession with him. What have the police learned from all this bad publicity? Are they changing their methods, or just hiring more spin doctors? If that is their response, then doesn't it leave them with a cruel advantage over those people who were deceased? Isn't it standard practice for some police to simply round up anybody who is a bit lost and write up a charge sheet for resisting arrest or assaulting an officer as insurance against questions about their own excessive use of force? When British police executed Jean Charles de Menezes on a crowded tube train and realized they had just done something incredibly outrageous, their PR office went to great lengths to try and protect their image, even photoshopping images of Menezes to make him look more like some other suspect in a wanted poster. To this day, they continue to refer to Menezes as a victim of the terrorists, could they be any more arrogant? While nobody believes the police woke up that morning thinking "let's kill some random guy on the tube", it is clear they made a mistake and like many people (not just police), they immediately prioritized protecting their reputation over protecting the truth. Nobody else knows exactly what Ian was doing and exactly what the police did to him. We may never know. However, any disparaging or irrelevant comments from the police should be viewed with some caution. The horrors of incarceration It would be hard for any of us to understand everything that an innocent person goes through when detained by the police. The recently released movie about The Stanford Prison Experiment may be an interesting place to start, a German version produced in 2001, Das Experiment, is also very highly respected. The United States has the largest prison population in the world and the second-highest per-capita incarceration rate. Many, including some on death row, are actually innocent, in the wrong place at the wrong time, without the funds to hire an attorney. The system, and the police and prison officers who operate it, treat these people as packages on a conveyor belt, without even the most basic human dignity. Whether their encounter lasts for just a few hours or decades, is it any surprise that something dies inside them when they discover this cruel side of American society? Worldwide, there is an increasing trend to make incarceration as degrading as possible. People may be innocent until proven guilty, but this hasn't stopped police in the UK from locking up and strip-searching over 4,500 children in a five year period, would these children go away feeling any different than if they had an encounter with Jimmy Saville or Rolf Harris? One can only wonder what they do to adults. What all this boils down to is that people shouldn't really be incarcerated unless it is clear the danger they pose to society is greater than the danger they may face in a prison. What can people do for Ian and for justice? Now that these unfortunate smears have appeared, it would be great to try and fill the Internet with stories of the great things Ian has done for the world. Write whatever you feel about Ian's work and your own experience of Debian. While the circumstances of the final tweets from his Twitter account are confusing, the tweets appear to be consistent with many other complaints about US law enforcement. Are there positive things that people can do in their community to help reduce the harm? Sending books to prisoners (the UK tried to ban this) can make a difference. Treat them like humans, even if the system doesn't. Recording incidents of police activities can also make a huge difference, such as the video of the shooting of Walter Scott or the UK police making a brutal unprovoked attack on a newspaper vendor. Don't just walk past a situation and assume everything is under control. People making recordings may find themselves in danger, it is recommended to use software that automatically duplicates each recording, preferably to the cloud, so that if the police ask you to delete such evidence, you can let them watch you delete it and still have a copy. Can anybody think of awards that Ian Murdock should be nominated for, either in free software, computing or engineering in general? Some, like the prestigious Queen Elizabeth Prize for Engineering can't be awarded posthumously but others may be within reach. Come and share your ideas on the debian-project mailing list, there are already some here. Best of all, Ian didn't just build software, he built an organization, Debian. Debian's principles have helped to unite many people from otherwise different backgrounds and carry on those principles even when Ian is no longer among us. Find out more, install it on your computer or even look for ways to participate in the project.

8 December 2015

Daniel Pocock: Comparison of free, open source accounting software

There are a diverse range of free software solutions for accounting. Personally, I have been tracking my personal and business accounts using a double-entry accounting system since I started doing freelance work about the same time I started university. Once you become familiar with double-entry accounting (which doesn't require much more than basic arithmetic skills and remembering the distinction between a debit and a credit) it is unlikely you would ever want to go back to a spreadsheet. Accounting software promoted for personal/home users often provides a very basic ledger where you can distinguish how much cash goes to rent, how much to food and how much to the tax man. Software promoted for business goes beyond the core ledger functionality and provides helpful ways to keep track of which bills you already paid, which are due imminently and which customers haven't paid you. Even for a one-man-band, freelancer or contractor, using a solution like this is hugely more productive than trying to track bills in a spreadsheet. Factors to consider when choosing a solution Changing accounting software can be a time consuming process and require all the users to learn a lot of new things. Therefore, it is generally recommended to start with something a little more powerful than what you need in the hope that you will be able to stick with it for a long time. With proprietary software this can be difficult because the more advanced solutions cost more money than you might be willing to pay right now. With free software, there is no such limitation and you can start with an enterprise-grade solution from day one and just turn off or ignore the features you don't need yet. If you are working as an IT consultant or freelancer and advising other businesses then it is also worthwhile to choose a solution for yourself that you can potentially recommend to your clients and customize for them. The comparison Here is a quick comparison of some of the free software accounting solutions that are packaged on popular Linux distributions like Debian, Ubuntu and Fedora:
Product Postbooks Tryton GnuCash LedgerSMB HomeBank Skrooge KMyMoney BG Financas Grisbi
Web UI Y Y N Y N N N N N
Multi-user Y Y N Y N N N N Y
File storage N Y Y N Y Y Y N N
SQL storage Y Y Y Y N N Y Y Y
Multi-currency Y Y Y Y N Y Y Y
Inventory Y Y N Y N N N
Linux Y Y Y Y Y Y Y Y Y
Windows Y Y
Mac OS Y Y
Technology C++, JavaScript, Node Python C Perl C Java
The table doesn't consider Odoo (formerly OpenERP) because the packages were considered buggy and are not maintained any more, it is replaced by Tryton. Compiere and Adempiere are other well known solutions but they haven't been packaged at all. Features in detail While the above list gives a basic summary of features, it is necessary to look more closely at how they are implemented. For example, if you need to report on VAT or GST, there are two methods of reporting: cash or accrual. Some products only support accruals because that is easier to implement. Even in commercial products that support cash-based VAT reporting, the reports are not always accurate (I've seen that problem with the proprietary Quickbooks software) and a tax auditor will be quick to spot such errors. The only real way to get to know one of these products is to test it for a couple of hours. Postbooks, for example, provides the Demo database so you can test it with dummy data without making any real commitment. User interface choices If you need to support users on multiple platforms or remote users such as an accountant or book-keeper, it is tempting to choose a solution with a web interface. The solutions with desktop interfaces can be provisioned to remote users using a terminal-server setup. The full GUI solutions tend to offer a richer user interface and reporting experience. It can frequently be useful to have multiple windows or reports open at the same time, doing this with browser tabs can be painful. File or database storage There are many good reasons to use database storage and my personal preference is for PostgreSQL. Using a database allows you to run a variety of third-party reporting tools and write your own scripts for data import and migration. Community and commercial support When dealing with business software, it is important to look at both the community and the commercial support offerings that are available. Some communities have events, such as xTupleCon for Postbooks or a presence at other major events like FOSDEM. Summary My personal choice at the moment is Postbooks from xTuple. This is because of a range of factors, including the availability of both web and desktop clients, true multi-user support, the multi-currency support and the PostgreSQL back-end.

8 November 2015

Daniel Pocock: Problems observed during Cambridge mini-DebConf RTC demo

A few problems were observed during the demo of RTC services at the Cambridge mini-DebConf yesterday. As it turns out, many of them are already documented and solutions are available for some of them. Multiple concurrent SIP registrations I had made some test calls on Friday using and I still had the site open in another tab in another browser window. When people tried to call me during the demo, both tabs were actually ringing but only one was visible. When a SIP client registers, the SIP registration server sends it a list of all other concurrent registrations in the response message. We simply need to extend JSCommunicator to inspect the response message and give some visual feedback about other concurrent registrations. Issue #69. SIP also provides a mechanism to clear concurrent registrations and that could be made available with a button or configuration option too (Issue #9). Callee hears ringing before connectivity checks completed The second issue during the WebRTC demo was that the callee (myself) was alerted about the call before the ICE checks had been performed. The optimal procedure to provide a slick user experience is to run the connectivity checks before alerting the callee. If the connectivity checks fail, the callee should never be alerted with a ringing sound and would never know somebody had tried to call. The caller would be told that the call was unable to be attempted and encouraged to consider trying again on another wifi network. RFC 5245 recommends that connectivity checks should be done first but it is not mandatory. One reason this is problematic with WebRTC is the need to display the pop-up asking the user for permission to share their microphone and webcam: the popup must appear before connectivity checks can commence. This has been discussed in the JsSIP issue tracker. Non-WebRTC softphones, such as Lumicall, do the connectivity checks before alerting the callee. Dealing with UDP blocking It appears the corporate wifi network in the venue was blocking the UDP packets so the connectivity checks could never complete, not even using a TURN server to relay the packets. People trying to use the service on home wifi networks, in small offices and mobile tethering should not have this problem as these services generally permit UDP by default. Some corporate networks, student accommodation and wifi networks in some larger hotels have blocked UDP and in these cases, additional effort must be made to get through the firewall. The TURN server we are running for also supports a TLS transport but it simply isn't configured yet. At the time we originally launched the WebRTC service in 2013, the browsers didn't support TURN over TLS at all but now they do. This is probably the biggest problem encountered during the demo but it does not require any code change to resolve this, just configuration, so a solution is well within reach. During the demo, we worked around the issue by turning off the wifi on my laptop and using tethering with a 4G mobile network. All the calls made successfully during the demo used the tethering solution. Add a connectivity check timeout The ICE connectivity checks appeared to keep running for a long time. Usually, if UDP is not blocked, the ICE checks would complete in less than two seconds. Therefore, the JavaScript needs to set a timeout between two and five seconds when it starts the checks and give the user a helpful warning about their network problems if the timeout is exceeded. Issue #73 in JSCommunicator. While these lengthy connectivity checks appear disappointing, it is worth remembering that this is an improvement over the first generation of softphones: none of them made these checks at all, they would simply tell the user the call had been answered but audio and video would only be working in one direction or not at all. Microphone issues One of the users calling into the demo, Juliana, was visible on the screen but we couldn't hear her. This was a local audio hardware issue with her laptop or headset. It would be useful if the JavaScript could provide visual feedback when it detects a voice (issue #74) and even better, integrating with the sound settings so that the user can see if the microphone is muted or the gain is very low (issue #75). Thanks to participants in the demo I'd like to thank all the participants in the demo, including Juliana Louback who called us from New York, Laura Arjona who called us from Madrid, Daniel Silverstone who called from about three meters away in the front row and Iain Learmonth who helped co-ordinate the test calls over IRC. Thanks are also due to Steve McIntyre, the local Debian community, ARM and the other sponsors for making another mini-DebConf in the UK this year.

28 October 2015

John Goerzen: The Train to Galesburg

Sometimes, children are so excited you just can t resist. Jacob and Oliver have been begging for a train trip for awhile now, so Laura and I took advantage of a day off school to take them to the little town of Galesburg, IL for a couple days. Galesburg is a special memory for me; nearly 5 years ago, it was the first time Jacob and I took an Amtrak trip somewhere, just the two of us. And, separately, Laura s first-ever train trip had been to Galesburg to visit friends. There was excitement in the air. I was asked to supply a bedtime story about trains I did. On the way to the train station in the middle of the night there was excited jabbering about trains. Even when I woke them up, they lept out of bed and raced downstairs, saying, Dad, why aren t you ready yet? As the train was passing through here at around 4:45AM, and we left home with some time to spare, we did our usual train trip thing of stopping at the one place open at such a time: Druber s Donuts. IMG_20151023_040731 Much as Laura and I might have enjoyed some sleep once we got on the train, Jacob and Oliver weren t having it. Way too much excitement was in the air. Jacob had his face pressed against the window much of the time, while Oliver was busy making snake trains from colored clay complete with eyes. IMG_20151023_062304 The boys were dressed up in their train hats and engineer overalls, and Jacob kept musing about what would happen if somebody got confused and thought that he was the real engineer. When an Amtrak employee played along with that later, he was quite thrilled! We were late enough into Galesburg that we ate lunch in the dining car. A second meal there what fun! Here they are anxiously awaiting the announcement that the noon reservations could make their way to the dining car. Oh, and jockeying for position to see who would be first and get to do the all-important job of pushing the button to open the doors between train cars. IMG_20151023_120143 Even waiting for your food can be fun. IMG_20151023_120728 Upon arriving, we certainly couldn t leave the train station until our train did, even though it was raining. IMG_20151023_145755 Right next to the train station is the Discovery Depot Children s Museum. It was a perfect way to spend a few hours. Jacob really enjoyed the building wall, where you can assemble systems that use gravity (really a kinetic/potential energy experiment wall) to funnel rubber balls all over the place. He sticks out his tongue when he s really thinking. Fun to watch. IMG_20151023_153113 Meanwhile, Oliver had a great time with the air-powered tube system, complete with several valves that can launch things through a complicated maze of transparent tubes. IMG_20151024_150309 VID_20151024_150159 They both enjoyed pretending I was injured and giving me rides in the ambulance. I was diagnosed with all sorts of maladies a broken leg, broken nose. One time Jacob held up the pretend stethoscope to me, and I said ribbit. He said, Dad, you ve got a bad case of frog! You will be in the hospital 190 days! Later I would make up things like I think my gezotnix is all froibled and I was ordered to never leave the ambulance again. He told the story of this several times. After the museum closed, we ate supper. Keep in mind the boys had been up since the middle of the night without sleeping and were still doing quite well! They did start to look a bit drowsy I thought Oliver was about to fall asleep, but then their food came. And at the hotel, they were perfectly happy to invent games involving jumping off the bed. Saturday, we rode over to Peck Park. We had heard about this park from members of our church in Kansas, but oddly even the taxi drivers hadn t ever heard of it. It s well known as a good place to watch trains, as it has two active lines that cross each other at a rail bridge. And sure enough, in only a little while, we took in several trains. IMG_20151024_110035 VID_20151024_110229 The rest of that morning, we explored Galesburg. We visited an antique mall and museum, saw the square downtown, and checked out a few of the shops my favorite was the Stray Cat, featuring sort of a storefront version of Etsy with people selling art from recycled objects. But that wasn t really the boys thing, so we drifted out of there on our way to lunch at Baked, where we had some delicious deep-dish pizza. After that, we still had some time to kill before getting back on the train. We discussed our options. And what do you know we ended up back at the children s museum. We stopped at a bakery to get the fixins for a light supper on the train, and ate a nice meal in the dining car once we got on. Then, this time, they actually slept. Before long, it was 3AM again and time to get back off the train. Oliver was zonked out sleepy. Somehow I managed to get his coat and backpack on him despite him being totally limp, and carried him downstairs to get off the train. Pretty soon we walked to our car and drove home. We tucked them in, and then finally tucked ourselves in. Sometimes being really tired is well worth it.

6 October 2015

Matthew Garrett: Going my own way

Reaction to Sarah's post about leaving the kernel community was a mixture of terrible and touching, but it's still one of those things that almost certainly won't end up making any kind of significant difference. Linus has made it pretty clear that he's fine with the way he behaves, and nobody's going to depose him. That's unfortunate, because earlier today I was sitting in a presentation at Linuxcon and remembering how much I love the technical side of kernel development. "Remembering" is a deliberate choice of word - it's been increasingly difficult to remember that, because instead I remember having to deal with interminable arguments over the naming of an interface because Linus has an undying hatred of BSD securelevel, or having my name forever associated with the deepthroating of Microsoft because Linus couldn't be bothered asking questions about the reasoning behind a design before trashing it.

In the end it's a mixture of just being tired of dealing with the crap associated with Linux development and realising that by continuing to put up with it I'm tacitly encouraging its continuation, but I can't be bothered any more. And, thanks to the magic of free software, it turns out that I can avoid putting up with the bullshit in the kernel community and get to work on the things I'm interested in doing. So here's a kernel tree with patches that implement a BSD-style securelevel interface. Over time it'll pick up some of the power management code I'm still working on, and we'll see where it goes from there. But, until there's a significant shift in community norms on LKML, I'll only be there when I'm being paid to be there. And that's improved my mood immeasurably.

(Edited to add a context link for the "deepthroating of Microsoft" reference)

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25 September 2015

Steve McIntyre: Linaro VLANd v0.4

VLANd is a python program intended to make it easy to manage port-based VLAN setups across multiple switches in a network. It is designed to be vendor-agnostic, with a clean pluggable driver API to allow for a wide range of different switches to be controlled together. There's more information in the README file. I've just released v0.4, with a lot of changes included since the last release: VLANd is Free Software, released under the GPL version 2 (or any later version). For now, grab it from git; tarballs will be coming shortly.