Search Results: "tar"

30 May 2021

Vincent Fourmond: QSoas quiz #2: averaging several Y values for the same X value

This second quiz may sound like the first one, but in fact, the approach used is completely different. The point is to gather some elementary statistics from a series of experiments performed under different conditions, but with several repeats at the same conditions.
Quiz You are given a file (which you can download there) that contains a series of pH value data: the X column is the pH, the Y column the result of the experiment at the given pH (let's say the measure of the catalytic rate of an enzyme). Your task is to take this data and produce a single dataset which contains, for each pH value, the pH, the average of the results at that pH and the standard deviation. The result should be identical to the following file, and should look like that:
There are several ways to do this, but all ways must rely on stats, and the more natural way in QSoas is to take advantage of split-on-values, which is a very powerful command but somehow hard to master, which is the point of this Quiz.
By the way, the data file is purely synthetic, if you look in the GitHub repository, you'll see how it was generated.

About QSoas QSoas is a powerful open source data analysis program that focuses on flexibility and powerful fitting capacities. It is released under the GNU General Public License. It is described in Fourmond, Anal. Chem., 2016, 88 (10), pp 5050 5052. Current version is 3.0. You can download its source code there (or clone from the GitHub repository) and compile it yourself, or buy precompiled versions for MacOS and Windows there.

Russ Allbery: Review: The Silver Chair

Review: The Silver Chair, by C.S. Lewis
Illustrator: Pauline Baynes
Series: Chronicles of Narnia #4
Publisher: Collier
Copyright: 1953
Printing: 1978
ISBN: 0-02-044250-5
Format: Mass market
Pages: 217
The Silver Chair is a sequel to The Voyage of the Dawn Treader and the fourth book of the Chronicles of Narnia in original publication order. (For more about publication order, see the introduction to my review of The Lion, the Witch and the Wardrobe.) Apart from a few references to The Voyage of the Dawn Treader at the start, it stands sufficiently on its own that you could read it without reading the other books, although I have no idea why you'd want to. We have finally arrived at my least favorite of the Narnia books and the one that I sometimes skipped during re-reads. (One of my objections to the new publication order is that it puts The Silver Chair and The Last Battle back-to-back, and I don't think you should do that to yourself as a reader.) I was hoping that there would be previously unnoticed depth to this book that would redeem it as an adult reader. Sadly, no; with one very notable exception, it's just not very good. MAJOR SPOILERS BELOW. The Silver Chair opens on the grounds of the awful school to which Eustace's parents sent him: Experiment House. That means it opens (and closes) with a more extended version of Lewis's rant about schools. I won't get into this in detail since it's mostly a framing device, but Lewis is remarkably vicious and petty. His snide contempt for putting girls and boys in the same school did not age well, nor did his emphasis at the end of the book that the incompetent head of the school is a woman. I also raised an eyebrow at holding up ordinary British schools as a model of preventing bullying. Thankfully, as Lewis says at the start, this is not a school story. This is prelude to Jill meeting Eustace and the two of them escaping the bullies via a magical door into Narnia. Unfortunately, that's the second place The Silver Chair gets off on the wrong foot. Jill and Eustace end up in what the reader of the series will recognize as Aslan's country and almost walk off the vast cliff at the end of the world, last seen from the bottom in The Voyage of the Dawn Treader. Eustace freaks out, Jill (who has a much better head for heights) goes intentionally close to the cliff in a momentary impulse of arrogance before realizing how high it is, Eustace tries to pull her back, and somehow Eustace falls over the edge. I do not have a good head for heights, and I wonder how much of it is due to this memorable scene. I certainly blame Lewis for my belief that pulling someone else back from the edge of a cliff can result in you being pushed off, something that on adult reflection makes very little sense but which is seared into my lizard brain. But worse, this sets the tone for the rest of the story: everything is constantly going wrong because Eustace and Jill either have normal human failings that are disproportionately punished or don't successfully follow esoteric and unreasonably opaque instructions from Aslan. Eustace is safe, of course; Aslan blows him to Narnia and then gives Jill instructions before sending her afterwards. (I suspect the whole business with the cliff was an authorial cheat to set up Jill's interaction with Aslan without Eustace there to explain anything.) She and Eustace have been summoned to Narnia to find the lost Prince, and she has to memorize four Signs that will lead her on the right path. Gah, the Signs. If you were the sort of kid that I was, you immediately went back and re-read the Signs several times to memorize them like Jill was told to. The rest of this book was then an exercise in anxious frustration. First, Eustace is an ass to Jill and refuses to even listen to the first Sign. They kind of follow the second but only with heavy foreshadowing that Jill isn't memorizing the Signs every day like she's supposed to. They mostly botch the third and have to backtrack to follow it. Meanwhile, the narrator is constantly reminding you that the kids (and Jill in particular) are screwing up their instructions. On re-reading, it's clear they're not doing that poorly given how obscure the Signs are, but the ominous foreshadowing is enough to leave a reader a nervous wreck. Worse, Eustace and Jill are just miserable to each other through the whole book. They constantly bicker and snipe, Eustace doesn't want to listen to her and blames her for everything, and the hard traveling makes it all worse. Lewis does know how to tell a satisfying redemption arc; one of the things I have always liked about Edmund's story is that he learns his lesson and becomes my favorite character in the subsequent stories. But, sadly, Eustace's redemption arc is another matter. He's totally different here than he was at the start of The Voyage of the Dawn Treader (to the degree that if he didn't have the same name in both books, I wouldn't recognize him as the same person), but rather than a better person he seems to have become a different sort of ass. There's no sign here of the humility and appreciation for friendship that he supposedly learned from his time as a dragon. On top of that, the story isn't very interesting. Rilian, the lost Prince, is a damp squib who talks in the irritating archaic accent that Lewis insists on using for all Narnian royalty. His story feels like Lewis lifted it from medieval Arthurian literature; most of it could be dropped into a collection of stories of knights of the Round Table without seeming out of place. When you have a country full of talking animals and weirdly fascinating bits of theology, it's disappointing to get a garden-variety story about an evil enchantress in which everyone is noble and tragic and extremely stupid. Thankfully, The Silver Chair has one important redeeming quality: Puddleglum. Puddleglum is a Marsh-wiggle, a bipedal amphibious sort who lives alone in the northern marshes. He's recruited by the owls to help the kids with their mission when they fail to get King Caspian's help after blowing the first Sign. Puddleglum is an absolute delight: endlessly pessimistic, certain the worst possible thing will happen at any moment, but also weirdly cheerful about it. I love Eeyore characters in general, but Puddleglum is even better because he gives the kids' endless bickering exactly the respect that it deserves.
"But we all need to be very careful about our tempers, seeing all the hard times we shall have to go through together. Won't do to quarrel, you know. At any rate, don't begin it too soon. I know these expeditions usually end that way; knifing one another, I shouldn't wonder, before all's done. But the longer we can keep off it "
It's even more obvious on re-reading that Puddleglum is the only effective member of the party. Jill has only a couple of moments where she gets the three of them past some obstacle. Eustace is completely useless; I can't remember a single helpful thing he does in the entire book. Puddleglum and his pessimistic determination, on the other hand, is right about nearly everything at each step. And he's the one who takes decisive action to break the Lady of the Green Kirtle's spell near the end. I was expecting a bit of sexism and (mostly in upcoming books) racism when re-reading these books as an adult given when they were written and who Lewis was, but what has caught me by surprise is the colonialism. Lewis is weirdly insistent on importing humans from England to fill all the important roles in stories, even stories that are entirely about Narnians. I know this is the inherent weakness of portal fantasy, but it bothers me how little Lewis believes in Narnians solving their own problems. The Silver Chair makes this blatantly obvious: if Aslan had just told Puddleglum the same information he told Jill and sent a Badger or a Beaver or a Mouse along with him, all the evidence in the book says the whole affair would have been sorted out with much less fuss and anxiety. Jill and Eustace are far more of a hindrance than a help, which makes for frustrating reading when they're supposedly the protagonists. The best part of this book is the underground bits, once they finally get through the first three Signs and stumble into the Lady's kingdom far below the surface. Rilian is a great disappointment, but the fight against the Lady's mind-altering magic leads to one of the great quotes of the series, on par with Reepicheep's speech in The Voyage of the Dawn Treader.
"Suppose we have only dreamed, or made up, all those things trees and grass and sun and moon and stars and Aslan himself. Suppose we have. Then all I can say is that, in that case, the made-up things seem a good deal more important than the real ones. Suppose this black pit of a kingdom of yours is the only world. Well, it strikes me as a pretty poor one. And that's a funny thing, when you come to think of it. We're just babies making up a game, if you're right. But four babies playing a game can make a play-world which licks your real world hollow. That's why I'm going to stand by the play world. I'm on Aslan's side even if there isn't any Aslan to lead it. I'm going to live as like a Narnian as I can even if there isn't any Narnia. So, thanking you kindly for our supper, if these two gentlemen and the young lady are ready, we're leaving your court at once and setting out in the dark to spend our lives looking for Overland. Not that our lives will be very long, I should think; but that's small loss if the world's as dull a place as you say."
This is Puddleglum, of course. And yes, I know that this is apologetics and Lewis is talking about Christianity and making the case for faith without proof, but put that aside for the moment, because this is still powerful life philosophy. It's a cynic's litany against cynicism. It's a pessimist's defense of hope. Suppose we have only dreamed all those things like justice and fairness and equality, community and consensus and collaboration, universal basic income and effective environmentalism. The dreary magic of the realists and the pragmatists say that such things are baby's games, silly fantasies. But you can still choose to live like you believe in them. In Alasdair Gray's reworking of a line from Dennis Lee, "work as if you live in the early days of a better nation." That's one moment that I'll always remember from this book. The other is after they kill the Lady of the Green Kirtle and her magic starts to fade, they have to escape from the underground caverns while surrounded by the Earthmen who served her and who they believe are hostile. It's a tense moment that turns into a delightful celebration when they realize that the Earthmen were just as much prisoners as the Prince was. They were forced from a far deeper land below, full of living metals and salamanders who speak from rivers of fire. It's the one moment in this book that I thought captured the magical strangeness of Narnia, that sense that there are wonderful things just out of sight that don't follow the normal patterns of medieval-ish fantasy. Other than a few great lines from Puddleglum and some moments in Aslan's country, the first 60% of this book is a loss and remarkably frustrating to read. The last 40% isn't bad, although I wish Rilian had any discernible character other than generic Arthurian knight. I don't know what Eustace is doing in this book at all other than providing a way for Jill to get into Narnia, and I wish Lewis had realized Puddleglum could be the protagonist. But as frustrating as The Silver Chair can be, I am still glad I re-read it. Puddleglum is one of the truly memorable characters of children's literature, and it's a shame he's buried in a weak mid-series book. Followed, in the original publication order, by The Horse and His Boy. Rating: 6 out of 10

29 May 2021

Shirish Agarwal: Planes, Pandemic and Medical Devices I

The Great Electric Airplane Race It took me quite sometime to write as have been depressed about things. Then a few days back saw Nova s The Great Electric Airplane Race. While it was fabulous and a pleasure to see and know that there are more than 200 odd startups who are in the race of making an electric airplane which works and has FAA certification. I was disappointed though that there no coverage of any University projects. From what little I know, almost all advanced materials which U.S. had made has been first researched in mostly Universities and when it is close to fruition then either spin-off as a startup or give to some commercial organization/venture to make it scalable and profitable. If they had, I am sure more people could be convinced to join sciences and engineering in college. I actually do want to come to this as part of both general medicine and vaccine development in U.S. but will come later. The idea that industry works alone should be discouraged, but that perhaps may require another article to articulate why I believe so.

Medical Device Ventilators in India Before the pandemic, probably most didn t know what a ventilator is and was, at least I didn t, although I probably used it during my somewhat brief hospital stay a couple of years ago. It entered into the Indian twitter lexicon more so in the second wave as the number of people who got infected became more and more and the ventilators which were serving them became less and less just due to sheer mismatch of numbers and requirements. Rich countries donated/gifted ventilators to India on which GOI put GST of 28%. Apparently, they are a luxury item, just like my hearing aid. Last week Delhi High Court passed a judgement that imposition of GST should not be on a gift like ventilators or oxygenators. The order can be found here. Even without reading the judgement the shout from the right was judicial activism while after reading it is a good judgement which touches on several points. The first, in itself, stating the dichotomy that if a commercial organization wanted to import a ventilator or an oxygenator the IGST payable is nil while for an individual it is 12%. The State (here State refers to State Government in this case Gujarat Govt.) did reduce the IGST for state from 12% to NIL IGST for federal states but that to till only 30.06.2021. No relief to individuals on that account. The Court also made use of Mr. Arvind Datar, as Amicus Curiae or friend of court. The petitioner, an 85-year-old gentleman who has put it up has put broad assertions under Article 21 (right to live) and the court in its wisdom also added Article 14 which enshrines equality of everyone before law. The Amicus Curiae, as his duty, guided the court into how the IGST law works and shared a brief history of the law and the changes happening before and after it. During his submissions, he also shared the Mega Exemption Notification no. 50/2017 under which several items are there which are exempted from putting IGST. The Amicus Curiae did note that such exemptions were also there before Mega Exemption Notification had come into play. However, DGFT (Directorate General of Foreign Trade) on 30-04-2021 issued notification No. 4/2015-2020 through which oxygenators had been exempted from Custom Duty/BCD (Basic Customs Duty. In another notification on no. 30/2021 dated 01.05.2021 it reduced IGST from 28% to 12% for personal use. If however the oxygenator was procured by a canalizing agency (bodies such as State Trading Corporation of India (STC) or/and Metals and Minerals Corporation (MMTC) and such are defined as canalising agents) then it will be fully exempted from paying any sort of IGST, albeit subject to certain conditions. What the conditions are were not shared in the open court. The Amicus Curiae further observed that it is contrary to practice where both BCD and IGST has been exempted for canalising agents and others, some IGST has to be paid for personal use. To share within the narrow boundaries of the topic, he shared entry no. 607A of General Exemption no.190 where duty and IGST in case of life-saving drugs are zero provided the life-saving drugs imported have been provided by zero cost from an overseas supplier for personal use. He further shared that the oxygen generator would fall in the same entry of 607A as it fulfills all the criteria as shared for life-saving medicines and devices. He also used the help of Drugs and Cosmetics Act 1940 which provides such a relief. The Amicus Curiae further noted that GOI amended its foreign trade policy (2015-2020) via notification no.4/2015-2020, dated 30.04.2021, issued by DGFT where Rakhi and life-saving drugs for personal use has been exempted from BCD till 30-07-2021. No reason not to give the same exemption to oxygenators which fulfill the same thing. The Amicus Curiae, further observes that there are exceptional circumstances provisions as adverted to in sub-section (2) of Section 25 of the Customs Act, whereby Covid-19 which is known and labelled as a pandemic where the distinctions between the two classes of individuals or agencies do not make any sense. While he did make the observation that exemption from duty is not a right, in the light of the pandemic and Article 14, it does not make sense to have distinctions between the two classes of importers. He further shared from Circular no. 9/2014-Customs, dated 19.08.2014 by CBEC (Central Board of Excise and Customs) which gave broad exemptions under Section 25 (2) of the same act in respect of goods and services imported for safety and rehabilitation of people suffering and effected by natural disasters and epidemics. He further submits that the impugned notification is irrational as there is no intelligible differentia rule applied or observed in classifying the import of oxygen concentrators into two categories. One, by the State and its agencies; and the other, by an individual for personal use by way of gift. So there was an absence of adequate determining principle . To bolster his argument, he shared the judgements of

a) Union of India vs. N.S. Rathnam & Sons, (2015) 10 SCC 681 (N.S. Ratnams and Sons Case) b) Shayara Bano vs. Union of India, (2017) 9 SCC 1 (Shayara Bano Case) The Amicus Curiae also rightly observed that the right to life also encompasses within it, the right to health. You cannot have one without the other and within that is the right to have affordable treatment. He further stated that the state does not only have a duty but a positive obligation is cast upon it to ensure that the citizen s health is secured. He again cited Navtej Singh Johars vs Union of India (Navtej Singh Johar Case) in defence of right to life. Mr. Datar also shared that unlike in normal circumstances, it is and should be enough to show distinct and noticeable burdensomeness which is directly attributable to the impugned/questionable tax. The gentleman cited Indian Express Newspapers (Bombay) Private Limited vs. Union of India, (1985) 1 SCC 641 (Indian Express case) 1985 which shared both about Article 19 (1) (a) and Article 21. Bloggers note At this juncture, I should point out which I am sharing the judgement and I would be sharing only the Amicus Curiae POV and then the judge s final observations. While I was reading it, I was stuck by the fact that the Amicus Curiae had cited 4 cases till now, 3 of them are pretty well known both in the legal fraternity and even among public at large. Another 3 which have been shared below which are also of great significance. Hence, felt the need to share the whole judgement. The Amicus Curiae further observed that this tax would have to be disproportionately will have to be paid by the old and the infirm, and they might find it difficult to pay the amounts needed to pay the customs duty/IGST as well as find the agent to pay in this pandemic. Blogger Note The situation with the elderly is something like this. Now there are a few things to note, only Central Govt. employees and pensioners get pensions which has been freezed since last year. The rest of the elderly population does not. The rate of interest has fallen to record lows from 5-6% in savings interest rate to 2% and on Fixed Deposits at 4.9% while the nominal inflation rate has up by 6% while CPI and real inflation rates are and would be much more. And this is when there is absolutely no demand in the economy. To add to all this, RBI shared a couple of months ago that fraud of 5 trillion rupees has been committed between 2015 and 2019 in banks. And this is different from the number of record NPA s that have been both in Public and Private Sector banks. To get out of this, the banks have squeezed their customers and are squeezing as well as asking GOI for bailouts. How much GOI is responsible for the frauds as well as NPA s would probably require its own space. And even now, RBI and banks have made heavy provisions as lockdowns are still a facet and are supposed to remain a facet till the end of the year or even next year (all depending upon when we get the vaccine). The Amicus Curiae further argued that the ventilators which are available locally are of bad quality. The result of all this has resulted in a huge amount of unsurmountable pressure on hospitals which they are unable to overcome. Therefore, the levy of IGST on oxygenators has direct impact on health of the citizen. So the examination of the law should not be by what intention it was but how it is affecting citizen rights now. For this he shared R.C.Cooper vs Union of India (another famous case R.C. Cooper vs Union of India) especially paragraph 49 and Federation of Hotel & Restaurant Association of India vs. Union of India, (1989) at paragraph 46 (Federation of Hotel Case) Mr. Datar further shared the Supreme Court order dated 18.12.2020, passed in Suo Moto Writ Petition(Civil) No.7/2020, to buttress the plea that the right to health includes the right to affordable treatment. Blogger s Note For those, who don t know Suo Moto is when the Court, whether Supreme Court or the High Courts take up a matter for public good. It could be in anything, law and order, Banking, Finance, Public Health etc. etc. This was the norm before 2014. The excesses of the executive were curtailed by both the Higher and the lower Judiciary. That is and was the reason that Judiciary is and was known as the third pillar of Indian democracy. A good characterization of Suo Moto can be found here. Before ending his submission, the learned Amicus Curiae also shared Jeeja Ghosh vs. Union of India, (2016) (Jeeja Ghosh Case, an outstanding case as it deals with people with disabilities and their rights and the observations made by the Division Bench of Hon ble Mr. Justice A. K. Sikri as well as Hon ble Mr. Justice R. K. Agrawal.) After Amicus Curiae completed his submissions, it was the turn of Mr. Sudhir Nandrajog, and he adopted the arguments and submissions made by the Amicus Curiae. The gentleman reiterated the facts of the case and how the impugned notification was violative of both Article 14 and 21 of the Indian Constitution. Blogger s Note The High Court s judgement which shows all the above arguments by the Amicus Curiae and the petitioner s lawyer also shared the State s view. It is only on page 24, where the Delhi High Court starts to share its own observations on the arguments of both sides. Judgement continued The first observation that the Court makes is that while the petitioner demonstrated that the impugned tax imposition would have a distinct and noticeable burdensomeness while the State did not state or share in any way how much of a loss it would incur if such a tax were let go and how much additional work would have to be done in order to receive this specific tax. It didn t need to do something which is down the wire or mathematically precise, but it didn t even care to show even theoretically how many people will be affected by the above. The counter-affidavit by the State is silent on the whole issue. The Court also contended that the State failed to prove how collecting IGST from the concerned individuals would help in fighting coronavirus in any substantial manner for the public at large. The High Court shared observations from the Navtej Singh Johar case where it is observed that the State has both negative and positive obligations to ensure that its citizens are able to enjoy the right to health. The High Court further made the point that no respectable person does like to be turned into a charity case. If the State contends that those who obey the law should pay the taxes then it is also obligatory on the state s part to lessen exactions such as taxes at the very least in times of war, famine, floods, epidemics and pandemics. Such an approach would lead a person to live a life of dignity which is part of Article 21 of the Constitution. Another point that was made by the State that only the GST council is able to make any changes as regards to exemptions rather than the State were found to be false as the State had made some exemptions without going to the GST council using its own powers under Section 25 of the Customs Act. The Court also points out that it does send a discriminatory pattern when somebody like petitioner has to pay the tax for personal use while those who are buying it for commercial use do not have to pay the tax. The Court agreed of the view of the Amicus Curiae, Mr. Datar that oxygenator should be taxed at NIL rate at IGST as it is part of life-saving drugs and oxygenator fits the bill as medical equipment as it is used in the treatment, mitigation and prevention of spread of Coronavirus. Mr. Datar also did show that oxygenator is placed at the same level as other life-saving drugs. The Court felt further emboldened as the observations by Supreme Court in State of Andhra Pradesh vs. Linde India Limited, 2020 ( State of Andhra Pradesh vs Linde Ltd.) The Court further shared many subsequent notifications from the State and various press releases by the State itself which does make the Court s point that oxygenators indeed are drugs as defined in the court case above. The State should have it as part of notification 190. This would preserve the start of the notification date from 03.05.2021 and the state would not have to issue a new notification. The Court further went to postulate that any persons similar to the petitioner could avail of the same, if they furnish a letter of undertaking to an officer designated by the State that the medical equipment would not be put to commercial use. Till the state does not do that, in the interim the importer could give the same undertaking to Joint Secretary, Customs or their nominee can hand over the same to custom officer. The Court also shared that it does not disagree with the State s arguments but the challenges which have arisen are in a unique time period/circumstances, so they are basing their judgement based on how the situation is. The Court also mentioned an order given by Supreme Court Diary No. 10669/2020 passed on 20.03.2020 where SC has taken pains to understand the issues faced by the citizens. The court also mentioned the Small Scale Industrial Manufactures Association Case (both of these cases I don t know) . So in conclusion, the Court holds the imposition of IGST on oxygenator which are imported by individuals as gifts from their relatives as unconstitutional. They also shared that any taxes taken by GOI in above scenario have to be returned. The relief to the state is they will not have to pay interest cost on the same. To check misuse of the same, the petitioner or people who are in similar circumstances would have to give a letter of undertaking to an officer designated by the State within 7 days of the state notifying the patient or anybody authorized by him/her to act on their behalf to share the letter of undertaking with the State. And till the State doesn t provide an officer, the above will continue. Hence, both the writ petition and the pending application are disposed off. The Registry is directed to release any money deposited by the petitioner along with any interest occurred on it (if any) . At the end they record appreciation of Mr. Arvind Datar, Mr. Zoheb Hossain, Mr. Sudhir Nandrajog as well as Mr. Siddharth Bambha. It is only due to their assistance that the court could reach the conclusion it did. For Delhi High Court RAJIV SHAKDHER, J. TALWANT SINGH, J. May 21, 2020 Blogger s Observations Now, after the verdict GOI does have few choices, either accept the verdict or appeal in the SC. A third choice is to make a committee and come to the same conclusions via the committee. GOI has done something similar in the past. If that happens and the same conclusions are reached as before, then the aggrieved may have no choice but to appear in the highest court of law. And this will put the aggrieved at a much more vulnerable place than before as SC court fees, lawyer fees etc. are quite high compared to High Courts. So, there is a possibility that the petitioner may not even approach unless and until some non-profit (NGO) does decide to fight and put it up as common cause or something similar. There is another judgement that I will share, probably tomorrow. Thankfully, that one is pretty short compared to this one. So it should be far more easier to read. FWIW, I did learn about the whole freeenode stuff and many channels who have shifted from freenode to libera. I will share my own experience of the same but that probably will take a day or two.
Zeeshan of IYC (India Youth Congress) along with Salman Khan s non-profit Being Human getting oxygenators
The above picture of Zeeshan. There have been a whole team of Indian Youth Congress workers (main opposition party to the ruling party) who have doing lot of relief effort. They have been buying Oxygenators from abroad with help of Being Human Foundation started by Salman Khan, an actor who works in A-grade movies in Bollywood.

28 May 2021

Jonathan Dowland: Queueing theory

Last year I began looking at queuing theory, to try and see if I could use it as a robust underpinning for a cost model to evaluate rewritten stream-processing programs. I started to work with my co-supervisor, Dr. Paul Ezhilchelvan, who is an expert in this area. In order to brief him on the work I'd done so far as well as my initial efforts to map queueing theory concepts onto Striot's concepts, I prepared a brief presentation:

Jonathan Dowland: Queuing theory

Last year I began looking at queuing theory, to try and see if I could use it as a robust underpinning for a cost model to evaluate rewritten stream-processing programs. I started to work with my co-supervisor, Dr. Paul Ezhilchelvan, who is an expert in this area. In order to brief him on the work I'd done so far as well as my initial efforts to map queueing theory concepts onto Striot's concepts, I prepared a brief presentation:

27 May 2021

Michael Prokop: What to expect from Debian/bullseye #newinbullseye

Bullseye Banner, Copyright 2020 Juliette Taka Debian v11 with codename bullseye is supposed to be released as new stable release soon-ish (let s hope for June, 2021! :)). Similar to what we had with #newinbuster and previous releases, now it s time for #newinbullseye! I was the driving force at several of my customers to be well prepared for bullseye before its freeze, and since then we re on good track there overall. In my opinion, Debian s release team did (and still does) a great job I m very happy about how unblock requests (not only mine but also ones I kept an eye on) were handled so far. As usual with major upgrades, there are some things to be aware of, and hereby I m starting my public notes on bullseye that might be worth also for other folks. My focus is primarily on server systems and looking at things from a sysadmin perspective. Further readings Of course start with taking a look at the official Debian release notes, make sure to especially go through What s new in Debian 11 + Issues to be aware of for bullseye. Chris published notes on upgrading to Debian bullseye, and also anarcat published upgrade notes for bullseye. Package versions As a starting point, let s look at some selected packages and their versions in buster vs. bullseye as of 2021-05-27 (mainly having amd64 in mind):
Package buster/v10 bullseye/v11
ansible 2.7.7 2.10.8
apache 2.4.38 2.4.46
apt 1.8.2.2 2.2.3
bash 5.0 5.1
ceph 12.2.11 14.2.20
docker 18.09.1 20.10.5
dovecot 2.3.4 2.3.13
dpkg 1.19.7 1.20.9
emacs 26.1 27.1
gcc 8.3.0 10.2.1
git 2.20.1 2.30.2
golang 1.11 1.15
libc 2.28 2.31
linux kernel 4.19 5.10
llvm 7.0 11.0
lxc 3.0.3 4.0.6
mariadb 10.3.27 10.5.10
nginx 1.14.2 1.18.0
nodejs 10.24.0 12.21.0
openjdk 11.0.9.1 11.0.11+9 + 17~19
openssh 7.9p1 8.4p1
openssl 1.1.1d 1.1.1k
perl 5.28.1 5.32.1
php 7.3 7.4+76
postfix 3.4.14 3.5.6
postgres 11 13
puppet 5.5.10 5.5.22
python2 2.7.16 2.7.18
python3 3.7.3 3.9.2
qemu/kvm 3.1 5.2
ruby 2.5.1 2.7+2
rust 1.41.1 1.48.0
samba 4.9.5 4.13.5
systemd 241 247.3
unattended-upgrades 1.11.2 2.8
util-linux 2.33.1 2.36.1
vagrant 2.2.3 2.2.14
vim 8.1.0875 8.2.2434
zsh 5.7.1 5.8
Linux Kernel The bullseye release will ship a Linux kernel based on v5.10 (v5.10.28 as of 2021-05-27, with v5.10.38 pending in unstable/sid), whereas buster shipped kernel 4.19. As usual there are plenty of changes in the kernel area and this might warrant a separate blog entry, but to highlight some issues: One surprising change might be that the scrollback buffer (Shift + PageUp) is gone from the Linux console. Make sure to always use screen/tmux or handle output through a pager of your choice if you need all of it and you re in the console. The kernel provides BTF support (via CONFIG_DEBUG_INFO_BTF, see #973870), which means it s no longer necessary to install LLVM, Clang, etc (requiring >100MB of disk space), see Gregg s excellent blog post regarding the underlying rational. Sadly the libbpf-tools packaging didn t make it into bullseye (#978727), but if you want to use your own self-made Debian packages, my notes might be useful. With kernel version 5.4, SUBDIRS support was removed from kbuild, so if an out-of-tree kernel module (like a *-dkms package) fails to compile on bullseye, make sure to use a recent version of it which uses M= or KBUILD_EXTMOD= instead. Unprivileged user namespaces are enabled by default (see #898446 + #987777), so programs can create more restricted sandboxes without the need to run as root or via a setuid-root helper. If you prefer to keep this feature restricted (or tools like web browsers, WebKitGTK, Flatpak, don t work), use sysctl -w kernel.unprivileged_userns_clone=0 . The /boot/System.map file(s) no longer provide the actual data, you need to switch to the dbg package if you rely on that information:
% cat /boot/System.map-5.10.0-6-amd64 
ffffffffffffffff B The real System.map is in the linux-image-<version>-dbg package
Be aware though, that the *-dbg package requires ~5GB of additional disk space. Systemd systemd v247 made it into bullseye (updated from v241). Same as for the kernel this might warrant a separate blog entry, but to mention some highlights: Systemd in bullseye activates its persistent journal functionality by default (storing its files in /var/log/journal/, see #717388). systemd-timesyncd is no longer part of the systemd binary package itself, but available as standalone package. This allows usage of ntp, chrony, openntpd, without having systemd-timesyncd installed (which prevents race conditions like #889290, which was biting me more than once). journalctl gained new options:
--cursor-file=FILE      Show entries after cursor in FILE and update FILE
--facility=FACILITY...  Show entries with the specified facilities
--image=IMAGE           Operate on files in filesystem image
--namespace=NAMESPACE   Show journal data from specified namespace
--relinquish-var        Stop logging to disk, log to temporary file system
--smart-relinquish-var  Similar, but NOP if log directory is on root mount
systemctl gained new options:
clean UNIT...                       Clean runtime, cache, state, logs or configuration of unit
freeze PATTERN...                   Freeze execution of unit processes
thaw PATTERN...                     Resume execution of a frozen unit
log-level [LEVEL]                   Get/set logging threshold for manager
log-target [TARGET]                 Get/set logging target for manager
service-watchdogs [BOOL]            Get/set service watchdog state
--with-dependencies                 Show unit dependencies with 'status', 'cat', 'list-units', and 'list-unit-files'
 -T --show-transaction              When enqueuing a unit job, show full transaction
 --what=RESOURCES                   Which types of resources to remove
--boot-loader-menu=TIME             Boot into boot loader menu on next boot
--boot-loader-entry=NAME            Boot into a specific boot loader entry on next boot
--timestamp=FORMAT                  Change format of printed timestamps
If you use systemctl edit to adjust overrides, then you ll now also get the existing configuration file listed as comment, which I consider very helpful. The MACAddressPolicy behavior with systemd naming schema v241 changed for virtual devices (I plan to write about this in a separate blog post). There are plenty of new manual pages: systemd also gained new unit configurations related to security hardening: Another new unit configuration is SystemCallLog= , which supports listing the system calls to be logged. This is very useful for for auditing or temporarily when constructing system call filters. The cgroupv2 change is also documented in the release notes, but to explicitly mention it also here, quoting from /usr/share/doc/systemd/NEWS.Debian.gz:
systemd now defaults to the unified cgroup hierarchy (i.e. cgroupv2).
This change reflects the fact that cgroups2 support has matured
substantially in both systemd and in the kernel.
All major container tools nowadays should support cgroupv2.
If you run into problems with cgroupv2, you can switch back to the previous,
hybrid setup by adding systemd.unified_cgroup_hierarchy=false to the
kernel command line.
You can read more about the benefits of cgroupv2 at
https://www.kernel.org/doc/html/latest/admin-guide/cgroup-v2.html
Note that cgroup-tools (lssubsys + lscgroup etc) don t work in cgroup2/unified hierarchy yet (see #959022 for the details). Configuration management puppet s upstream doesn t provide packages for bullseye yet (see PA-3624 + MODULES-11060), and sadly neither v6 nor v7 made it into bullseye, so when using the packages from Debian you re still stuck with v5.5 (also see #950182). ansible is also available, and while it looked like that only version 2.9.16 would make it into bullseye (see #984557 + #986213), actually version 2.10.8 made it into bullseye. chef was removed from Debian and is not available with bullseye (due to trademark issues). Prometheus stack Prometheus server was updated from v2.7.1 to v2.24.1, and the prometheus service by default applies some systemd hardening now. Also all the usual exporters are still there, but bullseye also gained some new ones: Virtualization docker (v20.10.5), ganeti (v3.0.1), libvirt (v7.0.0), lxc (v4.0.6), openstack, qemu/kvm (v5.2), xen (v4.14.1), are all still around, though what s new and noteworthy is that podman version 3.0.1 (tool for managing OCI containers and pods) made it into bullseye. If you re using the docker packages from upstream, be aware that they still don t seem to understand Debian package version handling. The docker* packages will not be automatically considered for upgrade, as 5:20.10.6~3-0~debian-buster is considered newer than 5:20.10.6~3-0~debian-bullseye:
% apt-cache policy docker-ce
  docker-ce:
    Installed: 5:20.10.6~3-0~debian-buster
    Candidate: 5:20.10.6~3-0~debian-buster
    Version table:
   *** 5:20.10.6~3-0~debian-buster 100
          100 /var/lib/dpkg/status
       5:20.10.6~3-0~debian-bullseye 500
          500 https://download.docker.com/linux/debian bullseye/stable amd64 Packages
Vagrant is available in version 2.2.14, the package from upstream works perfectly fine on bullseye as well. If you re relying on VirtualBox, be aware that upstream doesn t provide packages for bullseye yet, but the package from Debian/unstable (v6.1.22 as of 2021-05-27) works fine on bullseye (VirtualBox isn t shipped with stable releases since quite some time due to lack of cooperation from upstream on security support for older releases, see #794466). If you rely on the virtualbox-guest-additions-iso and its shared folders support, you might be glad to hear that v6.1.22 made it into bullseye (see #988783), properly supporting more recent kernel versions like present in bullseye. debuginfod There s a new service debuginfod.debian.net (see debian-devel-announce and Debian Wiki), which makes the debugging experience way smoother. You no longer need to download the debugging Debian packages (*-dbgsym/*-dbg), but instead can fetch them on demand, by exporting the following variables (before invoking gdb or alike):
% export DEBUGINFOD_PROGRESS=1    # for optional download progress reporting
% export DEBUGINFOD_URLS="https://debuginfod.debian.net"
BTW: if you can t rely on debuginfod (for whatever reason), I d like to point your attention towards find-dbgsym-packages from the debian-goodies package. Vim Sadly Vim 8.2 once again makes another change for bad defaults (hello mouse behavior!). When incsearch is set, it also applies to :substitute. This makes it veeeeeeeeeery annoying when running something like :%s/\s\+$// to get rid of trailing whitespace characters, because if there are no matches it jumps to the beginning of the file and then back, sigh. To get the old behavior back, you can use this:
au CmdLineEnter : let s:incs = &incsearch   set noincsearch
au CmdLineLeave : let &incsearch = s:incs
rsync rsync was updated from v3.1.3 to v3.2.3. It provides various checksum enhancements (see option --checksum-choice). We got new capabilities (hardlink-specials, atimes, optional protect-args, stop-at, no crtimes) and the addition of zstd and lz4 compression algorithms. And we got new options: OpenSSH OpenSSH was updated from v7.9p1 to 8.4p1, so if you re interested in all the changes, check out the release notes between those version (8.0, 8.1, 8.2, 8.3 + 8.4). Let s highlight some notable new features: Misc unsorted

26 May 2021

Ian Jackson: Disconnecting from Freenode

I have just disconnected from irc.freenode.net for the last time. You should do the same. The awful new de facto operators are using user numbers as a public justification for their behaviour. Specifically, I recommend that you: Note that mentioning libera in the channel topic of your old channels on freenode is likely to get your channel forcibly taken over by the new de facto operators of freenode. They won't tolerate you officially directing people to the competition. I did an investigation and writeup of this situation for the Xen Project. It's a little out of date - it doesn't have the latest horrible behaviours from the new regime - but I think it is worth pasting it here:
Message-ID: <24741.12566.639691.461134@mariner.uk.xensource.com>
From: Ian Jackson <iwj@xenproject.org>
To: xen-devel@lists.xenproject.org
CC: community.manager@xenproject.org
Subject: IRC networks
Date: Wed, 19 May 2021 16:39:02 +0100
Summary:
We have for many years used the Freenode IRC network for real-time
chat about Xen.  Unfortunately, Freenode is undergoing a crisis.
There is a dispute between, on the one hand, Andrew Lee, and on the
other hand, all (or almost all) Freenode volunteer staff.  We must
make a decision.
I have read all the publicly available materials and asked around with
my contacts.  My conclusions:
 * We do not want to continue to use irc.freenode.*.
 * We might want to use libera.chat, but:
 * Our best option is probably to move to OFTC https://www.oftc.net/
Discussion:
Firstly, my starting point.
I have been on IRC since at least 1993.  Currently my main public
networks are OFTC and Freenode.
I do not have any personal involvement with public IRC networks.  Of
the principals in the current Freenode dispute, I have only heard of
one, who is a person I have experience of in a Debian context but have
not worked closely with.
George asked me informally to use my knowledge and contacts to shed
light on the situation.  I decided that, having done my research, I
would report more formally and publicly here rather than just
informally to George.
Historical background:
 * Freenode has had drama before.  In about 2001 OFTC split off from
   Freenode after an argument over governance.  IIRC there was drama
   again in 2006.  Significant proportion of the Free Software world,
   including Debian, now use OFTC.  Debian switched in 2006.
Facts that I'm (now) pretty sure of:
 * Freenode's actual servers run on donated services; that is,
   the hardware is owned by those donating the services, and the
   systems are managed by Freenode volunteers, known as "staff".
 * The freenode domain names are currently registered to a limited
   liability company owned by Andrew Lee (rasengan).
 * At least 10 Freenode staff have quit in protest, writing similar
   resignation letters protesting about Andrew Lee's actions [1].  It
   does not appear that any Andrew Lee has the public support of any
   Freenode staff.
 * Andrew Lee claims that he "owns" Freenode.[2]
 * A large number of channel owners for particular Free Software
   projects who previously used Freenode have said they will switch
   away from Freenode.
Discussion and findings on Freenode:
There is, as might be expected, some murk about who said what to whom
when, what promises were made and/or broken, and so on.  The matter
was also complicated by the leaking earlier this week of draft(s) of
(at least one of) the Freenode staffers' resignation letters.
Andrew Lee has put forward a position statement [2].  A large part of
the thrust of that statement is allegations that the current head of
Freenode staff, tomaw, "forced out" the previous head, christel.  This
allegation is strongly disputed by by all those current (resigning)
Freenode staff I have seen comment.  In any case it does not seem to
be particularly germane; in none of my reading did tomaw seem to be
playing any kind of leading role.  tomaw is not mentioned in the
resignation letters.
Some of the links led to me to logs of discussions on #freenode.  I
read some of these in particular[3].  MB I haven't been able to verify
that these logs have not been tampered with.  Having said that and
taking the logs at face value, I found the rasengan writing there to
be disingenuous and obtuse.
Andrew Lee has been heavily involved in Bitcoin.  Bitcoin is a hive of
scum and villainy, a pyramid scheme, and an environmental disaster,
all rolled into one.  This does not make me think well of Lee.
Additionally, it seems that Andrew Lee has been involved in previous
governance drama involving a different IRC network, Snoonet.
I have come to the very firm conclusion that we should have nothing to
do with Andrew Lee, and avoid using services that he has some
effective control over.
Alternatives:
The departing Freenode staff are setting up a replacement,
"libera.chat".  This is operational but still suffering from teething
problems and of course has a significant load as it deals with an
influx of users on a new setup.
On the staff and trust question: As I say, I haven't heard of any of
the Freenode staff, with one exception.  Unfortunately the one
exception does not inspire confidence in me[4] - although NB that is
only one data point.
On the other hand, Debian has had many many years of drama-free
involvement with OFTC.  OFTC has a formal governance arrangement and
it is associated with Software in the Public Interest.  I notice that
the last few OFTC'[s annual officer elections have been run partly by
Steve McIntyre.  Steve is a friend of mine (and he is a former Debian
Project Leader) and I take his involvement as a good sign.
I recommend that we switch to using OFTC as soon as possible.
Ian.
References:
Starting point for the resigning Freenode staff's side [1]:
  https://gist.github.com/joepie91/df80d8d36cd9d1bde46ba018af497409
Andrew Lee's side [2]:
  https://gist.github.com/realrasengan/88549ec34ee32d01629354e4075d2d48
[3]
https://paste.sr.ht/~ircwright/7e751d2162e4eb27cba25f6f8893c1f38930f7c4
[4] I won't give the name since I don't want to be shitposting.


comment count unavailable comments

25 May 2021

Pavit Kaur: Journey to GSoC

I am really excited that my Google Summer of Code proposal with Debian for the project Debian Continuous Integration improvements has been accepted. Through this blog, I am here to share about my Pre-GSoC journey. alt text I knew about GSoC since my first year of college but had this misconception that only great coders get selected for GSoC which did not let me apply to the program until my 3rd year of engineering. I applied this year not because I thought I have turned into one but because I actually wanted to give a fair try to this before the time I become ineligible to participate.

Finding Project Scrolling through the list of GSoC 2021 organizations, I was checking out projects of organizations I am familiar with. Debian is one of the huge Open Source communities that has always inspired developers around the world to contribute to Open Source. So as I checked through Debian projects, I got excited to find the Debian Continuous Integration improvements project (referred to as debci in this post) related to web development and more concerned with backend work which is something I am very much interested in. I joined the community, and as directed by the application tasks of the project I set up the debci on my machine and started with an issue labeled as a newcomer. Soon I was able to submit my first Merge Request and it was reviewed by Antonio Terceiro, the mentor of my GSoC Project. With his further guidance, I was able to turn MR into an acceptable patch, and voila it got merged! That really did boost my morale to contribute further to the project.

Student Application Period At the suggestion of the mentor, during the Student Application Period, I worked on more open issues which were helping me understand the codebase better and in turn the deliverables of the project for my proposal. For my every doubt, I first tried to tackle it myself, and if still not able to find a solution I turn to mentors who did their best to answer my queries and this is how I completed my proposal and got it reviewed by Antonio before finally submitting it on 13th April. I still cannot express that feeling of satisfaction I achieved on submitting the proposal. I finally successfully applied for GSoC.

After Proposal Submission I did not stop my contribution after the Student Application period ended and kept on working on more issues which helped me stay in touch with the project and also because I was enjoying it a lot. I had already made up my mind to contribute more in Open Source as I learned and enjoyed plenty during this process.

Day of Results On 17th May, I got my acceptance mail at around 11:30 pm at night and I remember screaming and waking everybody up in my home to announce the news to them. It was truly the happiest moment for me.

Moment of Truth I would admit that I got involved with GSoC because of the reputation associated with it but things I learned during this pre GSoC period have made me realize the fun and learning opportunities associated with working opensource and I am here to stay for sure. I plan to write more blogs regarding my project and keep you guys updated about my work. Stay tuned!

Shirish Agarwal: Pandemic, Toolkit and India

Pandemic Situation in India. I don t know from where I should start. This is probably a good start. I actually would recommend Indiacable as they do attempt to share some things happening in India from day to day but still there is a lot thatt they just can t cover, nobody can cover. There were two reports which kind of shook me all inside. One which sadly came from the UK publication Independent, probably as no Indian publication would dare publish it. The other from Rural India. I have been privileged in many ways, including friends who have asked me if I need any financial help. But seeing reports like above, these people need more help, guidance and help than I. While I m never one to say give to Foundations. If some people do want to help people from Maharashtra, then moneylifefoundation could be a good place where they could donate. FWIW, they usually use the foundation to help savers and investors be safe and help in getting money when taken by companies with dubious intentions. That is their drive. Two articles show their bent. The first one is about the Algo scam which I have written previously about the same in this blog. Interestingly, when I talk about this scam, all Modi supporters are silent. The other one does give some idea as to why the Govt. is indifferent. That is going to a heavy cross for all relatives to bear. There has been a lot that has been happening. Now instead of being limited to cities, Covid has now gone hinterland in a big way. One could ask also Praveen as he probably knows what would be good for Kerala and surrounding areas. The biggest change, however, has been that India is now battling not just the pandemic but also Mucormycosis also known as black fungus and its deadlier cousin the white fungus. Mucormycosis came largely due to an ill-advise given that applying cow dung gives protection to Corona. And many applied it due to faith. And people who know science do know that in fact it has that bacteria. Sadly, those of us who are and were more interested in law, computer science etc. has now also have to keep on top of what is happening in the medical field. It isn t that I hate it, but it has a lot of costs. From what I could gather on various social media and elsewhere, a single injection of anti-fungal for the above costs INR 3k/- and that needs to be 5 times in a day and that course has to be for three weeks. So even the relatively wealthy people can and will become poor in no time. No wonder thousands of those went to UK, US, Dubai or wherever they could find safe-harbor from the pandemic with no plans of arriving back soon. There was also the whole bit about FBS or Fetal Bovin Serum. India ordered millions of blood serum products from abroad and continues to. This was quickly shut down as news on Social Media. Apparently, it is only the Indian cow which is worthy of reverence. All other cows and their children are fair game according to those in power. Of course, that discussion was quickly shut down as was the discussion about IGP (Indian Genome Project). People over the years had asked me why India never participated for the HGP (Human Gnome Project). I actually had no answer for that. Then in 2020, there was idea of IGP which was put up and then it was quickly shot down as the results could damage a political party s image. In fact, a note to people who want to join Indian civil services tells the reason exactly. While many countries in the world are hypocrites, including the U.S. none can take the place that India has made for itself in that field.

The Online experience The vaccination process has been made online and has led to severe heartburn and trouble for many including many memes. For e.g.

Daily work, get up, have a bath, see if you got a slot on the app, sleep.
People trying desperately to get a slot, taken from Hindi Movie Dilwale Dulhania Le Jaygenge.
Just to explain what is happening, one has to go to the website of cowin. Sharing a screenshot of the same.
Cowin app. sceeenshot
I have deliberately taken a screenshot of the cowin app. in U.P. which is one of the areas where the ruling party, BJP has. I haven t taken my state for the simple reason, even if a slot is open, it is of no use as there are no vaccines. As have been shared in India Cable as well as in many newspapers, it is the Central Govt. which holds the strings for the vaccines. Maharashtra did put up an international tender but to no effect. All vaccine manufacturers want only Central Govt. for purchases for multiple reasons. And GOI is saying it has no money even though recently it got loans as well as a dividend from RBI to the tune of 99k crore. For what all that money is, we have no clue. Coming back though, to the issue at hand. the cowin app. is made an open api. While normally, people like us should and are happy when an API is open, it has made those who understand how to use git, compile, etc. better than others. A copy of the public repo. of how you can do the same can be found on Github. Now, obviously, for people like me and many others it has ethical issues.

Kiran s Interview in Times of India (TOI) There isn t much to say apart from I haven t used it. I just didn t want to. It just is unethical. Hopefully, in the coming days GOI does something better. That is the only thing we are surviving on, hope.

The Toolkit saga A few days before, GOI shared a toolkit apparently made by Congress to defame the party in power. That toolkit was shared before the press and Altnews did the investigation and promptly shredded the claims. Congress promptly made an FIR in Chhattisgarh where it is in power. The gentleman who made the claims Mr. Sambit Patra refused to appear against the police without evidence citing personal reasons and asking 1 week to appear before them. Apart from Altnews which did a great job, sadly many people didn t even know that there is something called WYSIWYG. I had to explain that so many Industries, whether it is politics, creative industries, legal, ad industries, medical transcription, and imaging all use this, and all the participants use the same version of the software. The reason being that in most Industries, there is a huge loss and issue of legal liabilities if something untoward happens. For e.g. if medical transcription is done in India is wrong (although his or her work will be checked by a superior in the West), but for whatever reason is not, and a wrong diagnosis is put (due to wrong color or something) then a patient could die and the firm who does that work could face heavy penalties which could be the death of them. There is another myth that Congress has unlimited wealth or huge wealth. I asked if that was the case, why didn t they shift to Mac. Of course, none have answers on this one. There is another reason why they didn t want to appear. The Rona Wilson investigation by Arsenal Experts also has made them cautious. Previously, they had a free run. Nowadays, software forensic tools are available to one and all. For e.g. Debian itself has a good variety of tools for the same. I remember Vipin s sharing few years back. For those who want to start, just install the apps. and try figuring out. Expertise on using the tools takes years though, as you use the tool day in night. Update 25/05/2021 Apparently because Twitter made and showcased few tweets as Manipulated Media , those in Govt. are and were dead against it. So they conducted a raid against Twitter India headquarters, knowing fully well that there would be nobody except security. The moment I read this, my mind went to the whole Fruit of the poisonous tree legal doctrine. Sadly though, India doesn t recognize it and in fact, still believes in the pre-colonial era that evidence however collected is good. A good explanation of the same can be found here. There are some exceptions to the rule, but they are done so fine that more often than not, they can t be used in the court of law in India. Although a good RTI was shared by Mr. Saket Gokhale on the same issue, which does raise some interesting points
Twitter India Raid, Saket Gokhale RTI 1
Saket Gokhale RTI query , Twitter India Raid 2
FWIW, Saket has been successful in getting his prayers heard either as answers to RTI queries or then following it up in the various High Courts of India. Of course, those who are in the ruling party ridicule him but are unable to find faults in his application of logic. And quite a few times, I have learned from his applications as well as nuances or whatever is there in law, a judgment or a guideline which he invokes in his prayer. For e.g. the Lalitha Kumari Guidelines which the gentleman has shared in his prayer can be found here. Hence now, it would be upto the Delhi Police Cell to prove their case in response to RTI. He has also trapped them as he has shared they can t give excuses/exemptions which they have tried before. As I had shared earlier, High Courts in India have woken up, whether it is Delhi, Mumbai, Aurangabad, Madhya Pradesh, Uttar Pradesh, Odisha or Kerala. Just today i.e. on 25th May 2021, Justices Bela Trivedi and Justice Kalra had asked how come all the hospitals don t have NOC from the Fire De[partment. They also questioned the ASG (Assistant Solicitor General) as how BU (Building Use Certificate) has been granted as almost all the 400 hospitals are in residential area. To which the ASG replies, it is the same state in almost 4000 schools as well as 6000 odd factories in Ahemdabad alone, leave the rest of the district and state alone. And this is when last year strict instuctions were passed. They chose to do nothing sadly. I will share a link on this when bar and bench gives me  The Hindu also shared the whole raid on twitter saga.

Conclusion In conclusion, I sincerely do not where we are headed. The only thing I know is that we cannot expect things to be better before year-end and maybe even after that. It all depends on the vaccines and their availability. After that ruralindia article, I had to see quite a few movies and whatnot just to get that out of my head. And this is apart from the 1600 odd teachers and workers who have died in the U.P. poll duty. Now, what a loss, not just to the family members of the victims, but a whole generation of school children who would not be able to get quality teaching and be deprived of education. What will be their future, God only knows. The only good Bollywood movie which I saw was Ramprasad ki Teravi . The movie was an accurate representation of most families in and around me. There was a movie called Sansar (1987) which showed the breakup of the joint family and into a nuclear family. This movie could very well have been a continuation of the same. Even Marathi movies which at one time were very progressive have gone back to the same boy, girl love story routine. Sameer, though released in late 2020, was able to see it only recently. Vakeel Saab was an ok copy of Pink . I loved Sameer as, unlike Salman Khan films, it showed pretty much an authentic human struggle of a person who goes to the Middle East without any qualifications and works as a laborer and the trials he goes through. Somehow, Malayalam movies have a knack for showing truth without much of budget. Most of the Indian web series didn t make an impact. I think many of them were just going through the motions, it seems as everybody is concerned with the well-being of their near and dear ones. There was also this (Trigger Warning: This story discusses organized campaigns glorifying and advocating sexual violence against Muslim women.) Hoping people somehow make it to the other side of the pandemic.

24 May 2021

Antoine Beaupr : Leaving Freenode

The freenode IRC network has been hijacked. TL;DR: move to libera.chat or OFTC.net, as did countless free software projects including Gentoo, CentOS, KDE, Wikipedia, FOSDEM, and more. Debian and the Tor project were already on OFTC and are not affected by this.

What is freenode and why should I care? freenode is the largest remaining IRC network. Before this incident, it had close to 80,000 users, which is small in terms of modern internet history -- even small social networks are larger by multiple orders of magnitude -- but is large in IRC history. The IRC network is also extensively used by the free software community, being the default IRC network on many programs, and used by hundreds if not thousands of free software projects. I have been using freenode since at least 2006. This matters if you care about IRC, the internet, open protocols, decentralisation, and, to a certain extent, federation as well. It also touches on who has the right on network resources: the people who "own" it (through money) or the people who make it work (through their labor). I am biased towards open protocols, the internet, federation, and worker power, and this might taint this analysis.

What happened? It's a long story, but basically:
  1. back in 2017, the former head of staff sold the freenode.net domain (and its related company) to Andrew Lee, "American entrepreneur, software developer and writer", and, rather weirdly, supposedly "crown prince of Korea" although that part is kind of complex (see House of Yi, Yi Won, and Yi Seok). It should be noted the Korean Empire hasn't existed for over a century at this point (even though its flag, also weirdly, remains)
  2. back then, this was only known to the public as this strange PIA and freenode joining forces gimmick. it was suspicious at first, but since the network kept running, no one paid much attention to it. opers of the network were similarly reassured that Lee would have no say in the management of the network
  3. this all changed recently when Lee asserted ownership of the freenode.net domain and started meddling in the operations of the network, according to this summary. this part is disputed, but it is corroborated by almost a dozen former staff which collectively resigned from the network in protest, after legal threats, when it was obvious freenode was lost.
  4. the departing freenode staff founded a new network, irc.libera.chat, based on the new ircd they were working on with OFTC, solanum
  5. meanwhile, bot armies started attacking all IRC networks: both libera and freenode, but also OFTC and unrelated networks like a small one I help operate. those attacks have mostly stopped as of this writing (2021-05-24 17:30UTC)
  6. on freenode, however, things are going for the worse: Lee has been accused of taking over a channel, in a grotesque abuse of power; then changing freenode policy to not only justify the abuse, but also remove rules against hateful speech, effectively allowing nazis on the network (update: the change was reverted, but not by Lee)
Update: even though the policy change was reverted, the actual conversations allowed on freenode have already degenerated into toxic garbage. There are also massive channel takeovers (presumably over 700), mostly on channels that were redirecting to libera, but also channels that were still live. Channels that were taken over include #fosdem, #wikipedia, #haskell... Instead of working on the network, the new "so-called freenode" staff is spending effort writing bots and patches to basically automate taking over channels. I run an IRC network and this bot is obviously not standard "services" stuff... This is just grotesque. At this point I agree with this HN comment:
We should stop implicitly legitimizing Andrew Lee's power grab by referring to his dominion as "Freenode". Freenode is a quarter-century-old community that has changed its name to libera.chat; the thing being referred to here as "Freenode" is something else that has illegitimately acquired control of Freenode's old servers and user database, causing enormous inconvenience to the real Freenode.
I don't agree with the suggested name there, let's instead call it "so called freenode" as suggested later in the thread.

What now? I recommend people and organisations move away from freenode as soon as possible. This is a major change: documentation needs to be fixed, and the migration needs to be coordinated. But I do not believe we can trust the new freenode "owners" to operate the network reliably and in good faith. It's also important to use the current momentum to build a critical mass elsewhere so that people don't end up on freenode again by default and find an even more toxic community than your typical run-of-the-mill free software project (which is already not a high bar to meet). Update: people are moving to libera in droves. It's now reaching 18,000 users, which is bigger than OFTC and getting close to the largest, traditionnal, IRC networks (EFnet, Undernet, IRCnet are in the 10-20k users range). so-called freenode is still larger, currently clocking 68,000 users, but that's a huge drop from the previous count which was 78,000 before the exodus began. We're even starting to see the effects of the migration on netsplit.de. Update 2: the isfreenodedeadyet.com site is updated more frequently than netsplit and shows tons more information. It shows 25k online users for libera and 61k for so-called freenode (down from ~78k), and the trend doesn't seem to be stopping for so-called freenode. There's also a list of 400+ channels that have moved out. Keep in mind that such migrations take effect over long periods of time.

Where do I move to? The first thing you should do is to figure out which tool to use for interactive user support. There are multiple alternatives, of course -- this is the internet after all -- but here is a short list of suggestions, in preferred priority order:
  1. irc.libera.chat
  2. irc.OFTC.net
  3. Matrix.org, which bridges with OFTC and (hopefully soon) with libera as well, modern IRC alternative
  4. XMPP/Jabber also still exists, if you're into that kind of stuff, but I don't think the "chat room" story is great there, at least not as good as Matrix
Basically, the decision tree is this:
  • if you want to stay on IRC:
    • if you are already on many OFTC channels and few freenode channels: move to OFTC
    • if you are more inclined to support the previous freenode staff: move to libera
    • if you care about matrix users (in the short term): move to OFTC
  • if you are ready to leave IRC:
    • if you want the latest and greatest: move to Matrix
    • if you like XML and already use XMPP: move to XMPP
Frankly, at this point, everyone should seriously consider moving to Matrix. The user story is great, the web is a first class user, it supports E2EE (although XMPP as well), and has a lot of momentum behind it. It even bridges with IRC well (which is not the case for XMPP) so if you're worried about problems like this happening again. (Indeed, I wouldn't be surprised if similar drama happens on OFTC or libera in the future. The history of IRC is full of such epic controversies, takeovers, sabotage, attacks, technical flamewars, and other silly things. I am not sure, but I suspect a federated model like Matrix might be more resilient to conflicts like this one.) Changing protocols might mean losing a bunch of users however: not everyone is ready to move to Matrix, for example. Graybeards like me have been using irssi for years, if not decades, and would take quite a bit of convincing to move elsewhere. I have mostly kept my channels on IRC, and moved either to OFTC or libera. In retrospect, I think I might have moved everything to OFTC if I would have thought about it more, because almost all of my channels are there. But I kind of expect a lot of the freenode community to move to libera, so I am keeping a socket open there anyways.

How do I move? The first thing you should do is to update documentation, websites, and source code to stop pointing at freenode altogether. This is what I did for feed2exec, for example. You need to let people know in the current channel as well, and possibly shutdown the channel on freenode. Since my channels are either small or empty, I took the radical approach of:
  • redirecting the channel to ##unavailable which is historically the way we show channels have moved to another network
  • make the channel invite-only (which effectively enforces the redirection)
  • kicking everyone out of the channel
  • kickban people who rejoin
  • set the topic to announce the change
In IRC speak, the following commands should do all this:
/msg ChanServ set #anarcat mlock +if ##unavailable
/msg ChanServ clear #anarcat users moving to irc.libera.chat
/msg ChanServ set #anarcat restricted on
/topic #anarcat this channel has moved to irc.libera.chat
If the channel is not registered, the following might work
/mode #anarcat +if ##unavailable
Then you can leave freenode altogether:
/disconnect Freenode unacceptable hijack, policy changes and takeovers. so long and thanks for all the fish.
Keep in mind that some people have been unable to setup such redirections, because the new freenode staff have taken over their channel, in which case you're out of luck... Some people have expressed concern about their private data hosted at freenode as well. If you care about this, you can always talk to NickServ and DROP your nick. Be warned, however, that this assumes good faith of the network operators, which, at this point, is kind of futile. I would assume any data you have registered on there (typically: your NickServ password and email address) to be compromised and leaked. If your password is used elsewhere (tsk, tsk), change it everywhere. Update: there's also another procedure, similar to the above, but with a different approach. Keep in mind that so-called freenode staff are actively hijacking channels for the mere act of mentioning libera in the channel topic, so thread carefully there.

Last words This is a sad time for IRC in general, and freenode in particular. It's a real shame that the previous freenode staff have been kicked out, and it's especially horrible that if the new policies of the network are basically making the network open to nazis. I wish things would have gone out differently: now we have yet another fork in the IRC history. While it's not the first time freenode changes name (it was called OPN before), now the old freenode is still around and this will bring much confusion to the world, especially since the new freenode staff is still claiming to support FOSS. I understand there are many sides to this story, and some people were deeply hurt by all this. But for me, it's completely unacceptable to keep pushing your staff so hard that they basically all (except one?) resign in protest. For me, that's leadership failure at the utmost, and a complete disgrace. And of course, I can't in good conscience support or join a network that allows hate speech. Regardless of the fate of whatever we'll call what's left of freenode, maybe it's time for this old IRC thing to die already. It's still a sad day in internet history, but then again, maybe IRC will never die...

Vincent Bernat: Transient prompt with Zsh

Powerlevel10k is a theme for Zsh. It contains some powerful features, is astoundingly fast, and easy to customize. I am quite amazed at the skills of its main author. Be sure to also have a look at Zsh for Humans, a complete Zsh configuration including this theme. One of the nice features of Powerlevel10k is transient prompts: past prompts are reduced to a more minimal configuration to save space by removing unneeded information.
Demonstration of a transient prompt with Zsh: past prompts use a more compact form
My implementation of a transient prompt with Zsh. Past prompts are compact and include the time of the command execution, the hostname, and the status of the previous command while the complete prompt contains more information like the current directory and the Git branch.
When it comes to configuring my shell, I still prefer writing and understanding each line going into it. Therefore, I am still building my Zsh configuration from scratch. Here is how I have integrated the above transient feature into my prompt. The first step is to configure the appearance of the prompt in its compact form. Let s assume we have a variable, $_vbe_prompt_compact set to 1 when we want a compact prompt. We use the following function to define the prompt appearance:
_vbe_prompt ()  
    local retval=$?
    # When compact, just time + prompt sign
    if (( $_vbe_prompt_compact )); then
        # Current time (with timezone for remote hosts)
        _vbe_prompt_segment cyan default "%D %H:%M$ SSH_TTY+ %Z  "
        # Hostname for remote hosts
        [[ $SSH_TTY ]] && \
            _vbe_prompt_segment black magenta "%B%M%b"
        # Status of the last command
        if (( $retval )); then
            _vbe_prompt_segment red default $ PRCH[reta] 
        else
            _vbe_prompt_segment green cyan $ PRCH[ok] 
        fi
        # End of prompt
        _vbe_prompt_end
        return
    fi
    # Regular prompt with many information
    # [ ]
 
setopt prompt_subst
PS1='$(_vbe_prompt) '

Update (2021.05) The following part has been rewritten to be more robust. The code is stolen from Powerlevel10k s issue #888. See the comments for more details.

Our next step is to redraw the prompt after accepting a command. We wrap Zsh line editor into a function:1
_vbe-zle-line-init()  
    [[ $CONTEXT == start ]]   return 0
    # Start regular line editor
    (( $+zle_bracketed_paste )) && print -r -n - $zle_bracketed_paste[1]
    zle .recursive-edit
    local -i ret=$?
    (( $+zle_bracketed_paste )) && print -r -n - $zle_bracketed_paste[2]
    # If we received EOT, we exit the shell
    if [[ $ret == 0 && $KEYS == $'\4' ]]; then
        _vbe_prompt_compact=1
        zle .reset-prompt
        exit
    fi
    # Line edition is over. Shorten the current prompt.
    _vbe_prompt_compact=1
    zle .reset-prompt
    unset _vbe_prompt_compact
    if (( ret )); then
        # Ctrl-C
        zle .send-break
    else
        # Enter
        zle .accept-line
    fi
    return ret
 
zle -N zle-line-init _vbe-zle-line-init
That s all!
One downside of using the powerline fonts is that it messes with copy/paste. As I am using tmux, I use the following snippet to work around this issue and use only standard Unicode characters when copying from the terminal:
bind-key -T copy-mode M-w \
  send -X copy-pipe-and-cancel "sed 's/ .* /%/g'   xclip -i -selection clipboard" \;\
  display-message "Selection saved to clipboard!"
Copying and pasting the text from the screenshot above yields the following text:
14:21 % ssh eizo.luffy.cx
Linux eizo 4.19.0-16-amd64 #1 SMP Debian 4.19.181-1 (2021-03-19) x86_64
Last login: Fri Apr 23 14:20:39 2021 from 2a01:cb00:3f:b02:9db6:efa4:d85:7f9f
14:21 CEST % uname -a
Linux eizo 4.19.0-16-amd64 #1 SMP Debian 4.19.181-1 (2021-03-19) x86_64 GNU/Linux
14:21 CEST %
Connection to eizo.luffy.cx closed.
14:22 % git status
On branch article/zsh-transient
Untracked files:
  (use "git add <file>..." to include in what will be committed)
        ../../media/images/zsh-compact-prompt@2x.jpg
nothing added to commit but untracked files present (use "git add" to track)

  1. We have to manually enable bracketed paste because Zsh does it after zle-line-init.

23 May 2021

Sandro Tosi: QNAP: control LCD panel and speaker

LCD PanelMost (if not all) QNAP models come with an LCD display, in my model i got a 2 lines by 16 characters each. The tool to control the panel is:
/sbin/lcd_tool
but sometimes it's a bit stubborn in executing the commands, so as mentioned here you may want to killall -9 lcdmond and then issue the command you want; this is the snippet i'm using:
# print a msg on the panel
killall -9 lcdmond
/sbin/lcd_tool -1 "$LINE1" -2 "$LINE2"
sleep 5
# turn off screen light
killall -9 lcdmond
/sbin/lcd_tool -f
it ain't pretty, but it gets the job done.

Speaker / BuzzerIf you look for how to make your system beep, you may find these commands:
/sbin/pic_raw 80    Beep short
/sbin/pic_raw 81 Beep long
but they no longer work. So keep looking, i stumbled upon this post, mentioning hal_app, and that indeed works, but with a different syntax than the one presented at that link.In order to use hal_app to make a beep sound, the syntax that worked for me is:
/sbin/hal_app --se_buzzer enc_id=0,mode=XXX
If you remove entirely mode=XXX, it produces a short beep, but here is the list of all the modes available and their results (found out via exhaustive search):

code output
0 short beep (0.5 secs)
1 long beep (1 sec)
2 3x short beeps (0.5 secs), long pause (1 sec)
3-7, 10,
15, 16, 17,
18, 19, 20
2x long beeps (1 sec), very long pause (2 secs)
8, 9 3x long beeps (1 sec), very long pauses (2 secs)
12, 13 long beep, 2x very short pause (0.25) very short beep (0.25)
14 3x very short beep (0.25) very short pause (0.25)
(you can prepend as many 0 to the mode strings as you wish, so 000 is equivalent to 0, 000018 is equivalent to 18, and so on).PS: this article is based on my system, TVS-473 running firmware 4.5.3.1652PPS: friendly reminder that this is how you edit the crontab on a QNAP machine.

22 May 2021

Ritesh Raj Sarraf: Setting Up a Secure Webapp

As a person who prefers full access to data in the simplest format, while at the same time having it useful with latest technologies, my quest for trying things out is an ongoing activity. Earlier, I blogged about my needs of collating news feeds in a simple format, readily accessible offline, while still being useful and aligned with the modern paradigm. In today s age, the other common aspect of our life, is digitization of moments. With the advent of great technology and affordable economics, the world now has access to great devices to capture moments in digital form. Most people, these days, are equipped with smart devices, like mobile phones, that come with pretty good image capturing devices. Our lives, our societies, how we interact; a lot of it is now built around the assumption of smart devices and digital services. A lot of good things have happened of it. We are now able to send messages to people, securely, in a matter of seconds. We are now able to capture moments, which otherwise we d often miss; all thanks to devices like smart mobile phones that most of all carry almost all along with us. In this regard, we are quite indebted to the technology revolution that has improved life styles all over. Of course, like every coin has a flip side, thus too, too much of obsession with digital life, also has its drawbacks. A simple reminder to self should always be about what a human life is designed for and try to live by its rules.

Moments Given the tools general availability, we are all more used to capturing moments. Once upon a time, taking a photo meant going to a photo studio. Then came a generation where we d have personal devices with roll films, to which we captured the moments. And then get it processed from a photo developing service provider. And that is when we d know which all moments came out correct and which ones were spoilt. In such cases, there s always the wish I could have that moment again. Thankfully, now, in our current generation, we have the liberty to take pictures and validate them almost immediately. We also have the flexibility to take multiple shots of the moment and do the filtering later. There s also many intelligent and invasive services, all mostly provided free, to help you organize these moments; at a small cost of keeping an eye on your life activity. In a summary, mankind, now, generates lots and lots of data. So much lot that now even mammoths like Google are forced to make a call whether it is more profitable to sniff user activity while providing them a service for free, or ask people to pay otherwise too.

Privacy Many of us are wary of the amount of personal data we generate, which is our asset; and how the big tech giants want a piece of it in the name of free services. And in such quest, free aside, there s always a lookout for privacy savvy tools that can help us draw a bold line in between Public and Private

Google Photos Google Photos has been a great tool. The way it organizes, siphons and present your data is simply amazing. No good would have been the photos taken, if they weren t easily searchable, organized, annotated, and presented. But Google Photos is proprietary and invasive. The amount of information they have access to should be a concern to all people. For services that invade so much, the world needs Free Services.

PhotoPrism I only came across this project around a month ago, while the project has been around since 2019. So far, in my exploration, this is one of the best Free Software tools to manage and organize my digital photos. The other favorite tool that I regularly depend on is Digikam and it still is a gem. In a gist, PhotoPrism aims to be the equivalent of Google Photos, for the privacy savvy people. As of date, it has a decent list of features available. And for some of the missing ones, I ve come up with a fairly okay workflow with other tools, which is one of the reasons of this blog post. PhotoPrism is a web app, written in the Go Programming Language. Its layout and workflow as a Photo Management application is similar to Google Photos. It is very performant compared to other applications. Since it is a Progressive Web App, access through a Laptop, Tablet or Mobile is almost the same. It uses Google TensorFlow for some of its features and thus you feel like using Google Photos in some regard. Some shortcomings and workarounds
  • Facial Recognition: To date, facial recognition is a planned feature. But this was easy to tackle given that Digikam has pretty solid facial recognition. So I use Digikam to detect, recognize and annotate faces. And then PhotoPrism is happy enough to use those annotations and present relevant data.
  • HTTP Web App: The upstream project has done a good job of making use of Docker container technology in presenting this web app solution. A software solution, the equivalent of a Google Photos, does need a heavyweight config. In free software, it is all about reusing available tools. PhotoPrism makes use of tools like MySQL, Vue.js, TensorFlow, GoLang, GoLibs and strives to provide a single package solution, all thanks to Docker containers.
In its current offering, PhotoPrism is run as a HTTP Web App. I wanted to have an added layer of security on top of it. And thus run an nginx reverse proxy on top of it. Along with it, I run the proxy service on HTTPS, thus making all traffic from clients to the proxy encrypted. I also wanted an added layer of HTTP AUTH on top, so I explored some options and finally settled down with http-auth-digest Also, in the current implementation, PhotoPrism doesn t have a strong notion of normal and private photos in its data organization. I wanted normal photos available under a standard auth realm and private photos under a different realm. And along with a different realm, I also wanted some added security directives for it. So far, it looks like I ve put together a decent solution with the help of nginx.
  • First of all, since the port from the host is forwarded to the docker instance, that needed to be controlled. Instead of the default of listening on all interfaces, I changed it to loopback only. Because my primary and only interface is going to be the nginx reverse proxy
  • Setup nginx with a self-signed certificate to have all communication encrypted.
  • Setup nginx as a reverse proxy to talk to PhotoPrism.
    server  
       listen 80;
       listen [::]:80;
       server_name lenovo;
       return 302 https://$host$request_uri;
       rewrite ^ https://$http_host$request_uri? permanent;    # force redirect http to https
        server_tokens off;
     
    server  
    listen 443 ssl http2 default_server;
    listen [::]:443 ssl http2 default_server;
    ssl_certificate_key /etc/ssl/private/ssl-cert-snakeoil.key;
    ssl_certificate /etc/ssl/certs/ssl-cert-snakeoil.pem;
    server_tokens off;
    server_name lenovo;
    client_max_body_size 500M;
        auth_digest_expires 900s;
        auth_digest_evasion_time 5s;
        auth_digest_replays 500;
    location /private  
        auth_digest 'abc';
        auth_digest_user_file /etc/nginx/htdigest;
        auth_digest_expires 900s;
        auth_digest_evasion_time 5s;
        auth_digest_replays 500;
        proxy_pass http://localhost:2342/private;
     
    location /discover  
        auth_digest 'abc';
        auth_digest_user_file /etc/nginx/htdigest;
        auth_digest_expires 900s;
        auth_digest_evasion_time 5s;
        auth_digest_replays 500;
        proxy_pass http://localhost:2342/discover;
     
    location /  
        proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
        proxy_set_header Host $host;
        proxy_buffering off;
        proxy_http_version 1.1;
        proxy_set_header Upgrade $http_upgrade;
        proxy_set_header Connection "upgrade";
        proxy_pass http://localhost:2342;
          
        auth_basic "Priv";
        auth_basic_user_file /etc/nginx/htpasswd;
     
     
    
  • nginx packaging: I was so happy to see the simplicity of the nginx packaging in Debian. Becuase http-auth-digest is not upstream, it needs to be pulled in separately and compiled. I was happy to see how simple the packaging structure of nginx in Debian is. It was just a matter of putting in the module in the right modules location, which as structured such in the packaging falls under the debian/ packaging sub-folder, that any future upgrades will be quite easy to manage.
  • http-auth-digest: I d love to see http-auth-digest module be part of the upstream package. While I m a web n00b, I felt this module perfect for my use case. From what I ve understood, set up and tested so far, this module fills in all my requirements; which is more of like a session management.
With the combined setup in place, https://host is authenticated with a different set of credentials. On the other hand, https://host/discover and /private get covered with a different set of credentials and policies. While, this will continue to be an ongoing effort and audit of the services that I build, so far now, I feel this is in decent shape that I can use it as my daily driver. The end result is:
nginx auth prompt
nginx auth prompt
PhotoPrism Photo List
PhotoPrism Photo List
PhotoPrism Menu
PhotoPrism Menu

Updates
  • Things can really get frustrating at times. These days, it is Google that contributes to it. https://bugs.chromium.org/p/chromium/issues/detail?id=544244
    • It is is now fair to say that Google is big enough to rewrite all the standards. Or at least break them. Or best, their arrogance of it. This bug report is a fine example of what other ways it could have been dealt.

Mike Gabriel: Upcoming brainstorming discussion about Debian for the Enterprise

Recently, Raphael Hertzog published ideas [1] about how to make Debian more attractive for big enterprises. One missing key stone here is the possibility to sign up for an enterprise support subscription scheme. Another question tackles how to provide such a support scheme within Debian, without disturbing the current flow of how Debian is developed these days. And, there are likely more questions to asks, riddles to solve, and hurdles to overcome. We want to discuss this topic, brainstorm on it, collect new ideas and also hear your concerns on a public channel. Over the past weeks there already have been mail exchanges off-list. We want to reboot this privately started discussion now in public (as that's where it belongs) starting +/- at the end of the coming week via the currently quite inactive Debian mailing list 'debian-enterprise' [2]. Please join the discussion (and the mailing list) [3] if interested in this topic. light & love
Mike (aka sunweaver) [1] https://raphaelhertzog.com/2021/03/30/challenging-times-for-freexian-1/
(also read parts 2-4)
[2] debian-enterprise@lists.debian.org
[3] https://lists.debian.org/debian-enterprise

20 May 2021

Jonathan McDowell: Losing control to Kubernetes

GMK NucBox Kubernetes is about giving up control. As someone who likes to understand what s going on that s made it hard for me to embrace it. I ve also mostly been able to ignore it, which has helped. However I m aware it s incredibly popular, and there s some infrastructure at work that uses it. While it s not my responsibility I always find having an actual implementation of something is useful in understanding it generally, so I decided it was time to dig in and learn something new. First up, I should say I understand the trade-off here about handing a bunch of decisions off to Kubernetes about the underlying platform allowing development/deployment to concentrate on a nice consistent environment. I get the analogy with the shipping container model where you can abstract out both sides knowing all you have to do is conform to the TEU API. In terms of the underlying concepts I ve got some virtualisation and container experience, so I m not coming at this as a complete newcomer. And I understand multi-site dynamically routed networks. That said, let s start with a basic goal. I d like to understand k8s (see, I can be cool and use the short name) enough to be comfortable with what s going on under the hood and be able to examine a running instance safely (i.e. enough confidence about pulling logs, probing state etc without fearing I might modify state). That ll mean when I come across such infrastructure I have enough tools to be able to hopefully learn from it. To do this I figure I ll need to build myself a cluster and deploy some things on it, then poke it. I ll start by doing so on bare metal; that removes variables around cloud providers and virtualisation and gives me an environment I know is isolated from everything else. I happen to have a GMK NucBox available, so I ll use that. As a first step I m aiming to get a single node cluster deployed running some sort of web accessible service that is visible from the rest of my network. That should mean I ve covered the basics of a Kubernetes install, a running service and actually making it accessible. Of course I m running Debian. I ve got a Bullseye (Debian 11) install - not yet released as stable, but in freeze and therefore not a moving target. I wanted to use packages from Debian as much as possible but it seems that the bits of Kubernetes available in main are mostly just building blocks and not a great starting point for someone new to Kubernetes. So to do the initial install I did the following:
# Install docker + nftables from Debian
apt install docker.io nftables
# Add the Kubernetes repo and signing key
curl -s https://packages.cloud.google.com/apt/doc/apt-key.gpg > /etc/apt/k8s.gpg
cat > /etc/apt/sources.list.d/kubernetes.list <<EOF
deb [signed-by=/etc/apt/k8s.gpg] https://apt.kubernetes.io/ kubernetes-xenial main
EOF
apt update
apt install kubelet kubeadm kubectl
That resulted in a 1.21.1-00 install, which is current at the time of writing. I then used kubeadm to create the cluster:
kubeadm init --apiserver-advertise-address 192.168.53.147 --apiserver-cert-extra-sans udon.mynetwork
The extra parameters were to make the API server externally accessible from the host. I don t know if that was a good idea or not at this stage kubeadm spat out a bunch of instructions but the key piece was about copying the credentials to my user account. So I did:
mkdir ~noodles/.kube
cp -i /etc/kubernetes/admin.conf ~noodles/.kube/config
chown -R noodles ~noodles/.kube/
I then was able to see my pod:
noodles@udon:~$ kubectl get nodes
NAME   STATUS     ROLES                  AGE     VERSION
udon   NotReady   control-plane,master   4m31s   v1.21.1
Ooooh. But why s it NotReady? Seems like it s a networking issue and I need to install a networking provider. The documentation on this is appalling. Flannel gets recommended as a simple option but then turns out to need a --pod-network-cidr option passed to kubeadm and I didn t feel like cleaning up and running again (I ve omitted all the false starts it took me to get to this point). Another pointer was to Weave so I decided to try that with the following magic runes:
mkdir -p /var/lib/weave
head -c 16 /dev/urandom   shasum -a 256   cut -d " " -f1 > /var/lib/weave/weave-passwd
kubectl create secret -n kube-system generic weave-passwd --from-file=/var/lib/weave/weave-passwd
kubectl apply -f "https://cloud.weave.works/k8s/net?k8s-version=$(kubectl version   base64   tr -d '\n')&password-secret=weave-passwd&env.IPALLOC_RANGE=192.168.0.0/24"
(I believe what that s doing is the first 3 lines create a password and store it into the internal Kubernetes config so the weave pod can retrieve it. The final line then grabs a YAML config from Weaveworks to configure up weave. My intention is to delve deeper into what s going on here later; for now the primary purpose is to get up and running.) As I m running a single node cluster I then had to untaint my control node so I could use it as a worker node too:
kubectl taint nodes --all node-role.kubernetes.io/master-
And then:
noodles@udon:~$ kubectl get nodes
NAME   STATUS   ROLES                  AGE   VERSION
udon   Ready    control-plane,master   15m   v1.21.1
Result. What s actually running? Nothing except the actual system stuff, so we need to ask for all namespaces:
noodles@udon:~$ kubectl get pods --all-namespaces
NAMESPACE     NAME                           READY   STATUS    RESTARTS   AGE
kube-system   coredns-558bd4d5db-4nvrg       1/1     Running   0          18m
kube-system   coredns-558bd4d5db-flrfq       1/1     Running   0          18m
kube-system   etcd-udon                      1/1     Running   0          18m
kube-system   kube-apiserver-udon            1/1     Running   0          18m
kube-system   kube-controller-manager-udon   1/1     Running   0          18m
kube-system   kube-proxy-6d8kg               1/1     Running   0          18m
kube-system   kube-scheduler-udon            1/1     Running   0          18m
kube-system   weave-net-mchmg                2/2     Running   1          3m26s
These are all things I m going to have to learn about, but for now I ll nod and smile and pretend I understand. Now I want to actually deploy something to the cluster. I ended up with a simple HTTP echoserver (though it s not entirely clear that s actually the source for what I ended up pulling):
$ kubectl create deployment hello-node --image=k8s.gcr.io/echoserver:1.10
deployment.apps/hello-node created
$ kubectl get pod
NAME                          READY   STATUS    RESTARTS   AGE
hello-node-59bffcc9fd-8hkgb   1/1     Running   0          36s
$ kubectl expose deployment hello-node --type=NodePort --port=8080
$ kubectl get services
NAME         TYPE        CLUSTER-IP      EXTERNAL-IP   PORT(S)          AGE
hello-node   NodePort    10.107.66.138   <none>        8080:31529/TCP   1m
Looks good. And to test locally:
curl http://10.107.66.138:8080/

Hostname: hello-node-59bffcc9fd-8hkgb
Pod Information:
	-no pod information available-
Server values:
	server_version=nginx: 1.13.3 - lua: 10008
Request Information:
	client_address=192.168.53.147
	method=GET
	real path=/
	query=
	request_version=1.1
	request_scheme=http
	request_uri=http://10.107.66.138:8080/
Request Headers:
	accept=*/*
	host=10.107.66.138:8080
	user-agent=curl/7.74.0
Request Body:
	-no body in request-
Neat. But my external network is 192.168.53.0/24 and that s a 10.* address so how do I actually make it visible to other hosts? What I seem to need is an Ingress Controller which provide some sort of proxy between the outside world and pods within the cluster. Let s pick nginx because at least I have some vague familiarity with that and it seems like it should be able to do a bunch of HTTP redirection to different pods depending on the incoming request.
kubectl apply -f https://raw.githubusercontent.com/kubernetes/ingress-nginx/controller-v0.46.0/deploy/static/provider/cloud/deploy.yaml
I then want to expose the hello-node to the outside world and I finally had to write some YAML:
cat > hello-ingress.yaml <<EOF
apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
  name: example-ingress
  annotations:
    nginx.ingress.kubernetes.io/rewrite-target: /$1
spec:
  rules:
    - host: udon.mynetwork
      http:
        paths:
          - path: /
            pathType: Prefix
            backend:
              service:
                name: hello-node
                port:
                  number: 8080
EOF
i.e. incoming requests to http://udon.mynetwork/ should go to the hello-node on port 8080. I applied this:
$ kubectl apply -f hello-ingress.yaml
ingress.networking.k8s.io/example-ingress created
$ kubectl get ingress
NAME              CLASS    HOSTS            ADDRESS   PORTS   AGE
example-ingress   <none>   udon.mynetwork             80      3m8s
No address? What have I missed? Let s check the nginx service, which apparently lives in the ingress-nginx namespace:
noodles@udon:~$ kubectl get services -n ingress-nginx
NAME                                 TYPE           CLUSTER-IP      EXTERNAL-IP   PORT(S)                    AGE
ingress-nginx-controller             LoadBalancer   10.96.9.41      <pending>     80:32740/TCP,443:30894/TCP 13h
ingress-nginx-controller-admission   ClusterIP      10.111.16.129   <none>        443/TCP                    13h
<pending> does not seem like something I want. Digging around it seems I need to configure the external IP. So I do:
kubectl patch svc ingress-nginx-controller -n ingress-nginx -p \
	' "spec":  "type": "LoadBalancer", "externalIPs":["192.168.53.147"] '
and things look happier:
noodles@udon:~$ kubectl get services -n ingress-nginx
NAME                                 TYPE           CLUSTER-IP      EXTERNAL-IP      PORT(S)                 AGE
ingress-nginx-controller             LoadBalancer   10.96.9.41      192.168.53.147   80:32740/TCP,443:30894/TCP   14h
ingress-nginx-controller-admission   ClusterIP      10.111.16.129   <none>           443/TCP                 14h
noodles@udon:~$ kubectl get ingress
NAME              CLASS    HOSTS           ADDRESS          PORTS   AGE
example-ingress   <none>   udon.mynetwork  192.168.53.147   80      14h
Let s try a curl from a remote host:
curl http://udon.mynetwork/

Hostname: hello-node-59bffcc9fd-8hkgb
Pod Information:
	-no pod information available-
Server values:
	server_version=nginx: 1.13.3 - lua: 10008
Request Information:
	client_address=192.168.0.5
	method=GET
	real path=/
	query=
	request_version=1.1
	request_scheme=http
	request_uri=http://udon.mynetwork:8080/
Request Headers:
	accept=*/*
	host=udon.mynetwork
	user-agent=curl/7.64.0
	x-forwarded-for=192.168.53.136
	x-forwarded-host=udon.mynetwork
	x-forwarded-port=80
	x-forwarded-proto=http
	x-real-ip=192.168.53.136
	x-request-id=6aaef8feaaa4c7d07c60b2d05c45f75c
	x-scheme=http
Request Body:
	-no body in request-
Ok, so that seems like success. I ve got a single node cluster running a single actual application pod (the echoserver) and exporting it to the outside world. That s enough to start poking under the hood. Which is for another post, as this one is already getting longer than I d like. I ll just leave some final thoughts of things I need to work out:

19 May 2021

Martin-&#201;ric Racine: WebRTC fails tests on Firefox 78.10.0esr (64-bit)

Having to participate in many online events since the COVID crisis started, I've come to notice that few of the online clients work properly on the current Firefox ESR found in Debian. A quick visit at WebRTC Test confirmed that none of the tests in the Network and Connectivity section pass. Meanwhile, a Windows 10 laptop running Edge via the same network works just fine, so I have to assume that either a Firefox or Debian packaging issue is to blame, but I wouldn't know where to start. Any help? Thanks!

Marco d'Itri: My resignation from freenode

As it is now known, the freenode IRC network has been taken over by a Trumpian wannabe korean royalty bitcoins millionaire. To make a long story short, the former freenode head of staff secretly "sold" the network to this person even if it was not hers to sell, and our lawyers have advised us that there is not much that we can do about it without some of us risking financial ruin. Fuck you Christel, lilo's life work did not deserve this. What you knew as freenode after 12:00 UTC of May 19 will be managed by different people. As I have no desire to volunteer under the new regime, this marks the end of my involvement with freenode. It had started in 1999 when I encouraged the good parts of #linux-it to leave ircnet, and soon after I became senior staff. Even if I have not been very active recently, at this point I was the longest-serving freenode staff member and now I expect that I will hold this record forever. The people that I have met on IRC, on freenode and other networks, have been and still are a very important part of my life, second only to the ones that I have known thanks to Usenet. I am not fine, but I know that the communities which I have been a part of are not defined by a domain name and will regroup somewhere else. The current freenode staff members have resigned with me, these are some of their farewell messages:
  • amdj
  • edk
  • emilsp
  • Fuchs
  • jess
  • JonathanD
  • kline
  • niko
  • mniip
  • Swant
  • Together we have created Libera.Chat, a new IRC network based on the same principles of the old freenode.

    17 May 2021

    Dominique Dumont: Important bug fix for OpenSsh cme config editor

    The new release of Config::Model::OpenSsh fixes a bugs that impacted experienced users: the order of Hosts or Match sections is now preserved when writing back ~/.ssh/config file. Why does this matter ? Well, the beginning of ssh_config man page mentions that For each parameter, the first obtained value will be used. and Since the first obtained value for each parameter is used, more host-specific declarations should be given near the beginning of the file, and general defaults at the end. . Looks like I missed these statements when I designed the model for OpenSsh configuration: the Host section was written back in a neat, but wrong, alphabetical order. This does not matter except when there an overlap between the specifications of the Host (or Match) sections like in the example below:
    Host foo.company.com
    Port 22
    Host *.company.com
    Port 10022
    With this example, ssh connection to foo.company.com is done using port 22 and connection to bar.company.com with port 10022. If the Host sections are written back in reverse order:
    Host *.company.com
    Port 10022
    Host foo.company.com
    Port 22
    Then, ssh would be happy to use the first matching section for foo.company.com , i.e. *.company.com and would use the wrong port (10022) This is now fixed with Config::Model::OpenSsh 2.8.4.3 which is available on cpan and in Debian/experimental. While I was at it, I ve also updated Managing OpenSsh configuration with cme wiki page. All the best

    16 May 2021

    Carl Chenet: How to save up to 500 /year switching from Mailchimp to Open Source Mailtrain and AWS SES

    My newsletter Le Courrier du hacker (3,800 subscribers, 176 issues) is 3 years old and Mailchimp costs were becoming unbearable for a small project ($50 a month, $600 a year), with still limited revenues nowadays. Switching to the Open Source Mailtrain plugged to the AWS Simple Email Service (SES) will dramatically reduce the associated costs. First things first, thanks a lot to Pierre-Gilles Leymarie for his own article about switching to Mailtrain/SES. I owe him (and soon you too) so much. This article will be a step-by-step about how to set up Mailtrain/SES on a dedicated server running Linux. What s the purpose of this article? Mailchimp is more and more expensive following the growth of your newsletter subscribers and you need to leave it. You can use Mailtrain, a web app running on your own server and use the AWS SES service to send emails in an efficient way, avoiding to be flagged as a spammer by the other SMTP servers (very very common, you can try but you have been warned against  Prerequisites You will need the following prerequisites : Steps This is a fairly straightforward setup if you know what you re doing. In the other case, you may need the help of a professional sysadmin. You will need to complete the following steps in order to complete your setup: Configure AWS SES Verify your domain You need to configure the DKIM to certify that the emails sent are indeed from your own domain. DKIM is mandatory, it s the de-facto standard in the mail industry. Ask to verify your domain
    Ask AWS SES to verify a domain
    Generate the DKIM settings
    Generate the DKIM settings
    Use the DKIM settings
    Now you have your DKIM settings and Amazon AWS is waiting for finding the TXT field in your DNS zone. Configure your DNS zone to include DKIM settings I can t be too specific for this section because it varies A LOT depending on your DNS provider. The keys is: as indicated by the previous image you have to create one TXT record and two CNAME records in your DNS zone. The names, the types and the values are indicated by AWS SES. If you don t understand what s going here, there is a high probabiliy you ll need a system administrator to apply these modifications and the next ones in this article. Am I okay for AWS SES ? As long as the word verified does not appear for your domain, as shown in the image below, something is wrong. Don t wait too long, you have a misconfiguration somewhere.
    AWS SES pending verification
    When your domain is verified, you ll also receive an email to inform you about the successful verification. SMTP settings The last step is generating your credentials to use the AWS SES SMTP server. IT is really straightforward, providing the STMP address to use, the port, and a pair of username/password credentials.
    AWS SES SMTP settings and credentials
    Just click on Create My SMTP Credentials and follow the instructions. Write the SMTP server address somewhere and store the file with credentials on your computer, we ll need them below. Configure your server As we said before, we need a baremetal server or a virtual machine running a recent Linux. Configure your MySQL/MariaDB database We create a user mailtrain having all rights on a new database mailtrain.
    MariaDB [(none)]> create database mailtrain;
    Query OK, 1 row affected (0.00 sec)
    MariaDB [(none)]> CREATE USER 'mailtrain' IDENTIFIED BY 'V3rYD1fF1cUlTP4sSW0rd!';
    Query OK, 0 rows affected (0.01 sec)
    MariaDB [(none)]> GRANT ALL PRIVILEGES ON mailtrain.* TO 'mailtrain'@localhost IDENTIFIED BY 'V3rYD1fF1cUlTP4sSW0rd!';
    Query OK, 0 rows affected (0.00 sec)
    MariaDB [(none)]> FLUSH PRIVILEGES;
    Query OK, 0 rows affected (0.00 sec)
    MariaDB [(none)]> show databases;
    +--------------------+
      Database            
    +--------------------+
      information_schema  
      mailtrain           
      mysql               
      performance_schema  
    +--------------------+
    6 rows in set (0.00 sec)
    MariaDB [(none)]> Bye
    Configure your web server I use Nginx and I ll give you the complete setup for it, including generating Let s Encrypt. Configure Let s Encrypt You need to stop Nginx as root: systemctl stop nginx Then get the certificate only, I ll give the Nginx Vhost configuration: certbot certonly -d mailtrain.toto.com Install Mailtrain On your server create the following directory: mkdir -p /var/www/
    cd /var/www
    wget https://github.com/Mailtrain-org/mailtrain/archive/refs/tags/v1.24.1.tar.gz
    tar zxvf v1.24.1.tar.gz
    Modify the file /var/www/mailtrain/config/production.toml to use the MySQL settings:
    [mysql]
    host="localhost"
    user="mailtrain"
    password="V3rYD1ff1culT!"
    database="mailtrain"
    Now launch the Mailtrain process in a screen:
    screen
    NODE_ENV=production npm start
    Now Mailtrain is launched and should be running. Yeah I know it s ugly to launch like this (root process in a screen, etc) you can improve security with the following commands:
    groupadd mailtrain
    useradd -g mailtrain
    chown -R mailtrain:mailtrain /var/www/mailtrain 
    Now create the following file in /etc/systemd/system/mailtrain.service
    [Unit]
     Description=mailtrain
     After=network.target
    [Service]
     Type=simple
     User=mailtrain
     WorkingDirectory=/var/www/mailtrain/
     Environment="NODE_ENV=production"
     Environment="PORT=3000"
     ExecStart=/usr/bin/npm run start
     TimeoutSec=15
     Restart=always
    [Install]
     WantedBy=multi-user.target
    To register the following systemd unit and to launch the new Mailtrain daemon, use the following commands (do not forget to kill your screen session if you used it before):
    systemctl daemon-reload
    systemctl start mailtrain.service
    Now Mailtrain is running under the classic user mailtrain of the mailtrain system group. Configure the Nginx Vhost configuration for your domain Here is my configuration for the Mailtrain Nginx Vhost:
    map $http_upgrade $connection_upgrade  
      default upgrade;
      ''      close;
     
    server  
      listen 80; 
      listen [::]:80;
      server_name mailtrain.toto.com;
      return 301 https://$host$request_uri;
     
    server  
      listen 443 ssl;
      listen [::]:443 ssl;
      server_name mailtrain.toto.com;
      access_log /var/log/nginx/mailtrain.toto.com.access.log;
      error_log /var/log/nginx/mailtrain.toto.com.error.log;
      ssl_protocols TLSv1.2;
      ssl_ciphers EECDH+AESGCM:EECDH+AES;
      ssl_ecdh_curve prime256v1;
      ssl_prefer_server_ciphers on; 
      ssl_session_cache shared:SSL:10m;
      ssl_certificate     /etc/letsencrypt/live/mailtrain.toto.com/fullchain.pem;
      ssl_certificate_key /etc/letsencrypt/live/mailtrain.toto.com/privkey.pem;
      keepalive_timeout    70; 
      sendfile             on;
      client_max_body_size 0;
      root /var/www/mailtrain;
      location ~ /\.well-known\/acme-challenge  
        allow all;
       
      gzip on; 
      gzip_disable "msie6";
      gzip_vary on; 
      gzip_proxied any;
      gzip_comp_level 6;
      gzip_buffers 16 8k; 
      gzip_http_version 1.1;
      gzip_types text/plain text/css application/json application/javascript text/xml application/xml application/xml+rss text/javascript;
      add_header Strict-Transport-Security "max-age=31536000";
      location /   
        try_files $uri @proxy;
       
      location @proxy  
        proxy_set_header Host $host;
        proxy_set_header X-Real-IP $remote_addr;
        proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
        proxy_set_header X-Forwarded-Proto https;
        proxy_pass http://127.0.0.1:3000;
       
     
    Now Nginx is ready. Just start it:
    systemctl start nginx
    This Nginx vhost will redirect all http requests coming to the Mailtrain process running on the 3000 port. Now it s time to setup Mailtrain! Setup Mailtrain You should be able to access your Mailtrain at https://mailtrain.toto.com Mailtrain is quite simple to configure, Here is my mailer setup. Mailtrain just forwards emails to AWS SES. We only have to plug Mailtrain to AWS SES.
    Mailtrain mailer setup
    The hostname is provided by AWS SES in the STMP Settings section. Use the 465 port and USE TLS option. Next is providing your AWS SES username and password you generated above and stored somewhere on your computer. One of the issues I encountered is the AWS SES rate limit. Send too many emails too fast will get you flagged as a spammer. So I had to throttle Mailtrain. Because I m a lazy man, I asked Pierre-Gilles Leymarie his setup. Quite easier than determining myself the good one. Here is my setup. Works fine for my soon-to-be 4k subscribers. The idea is: if your AWS SES lets you know you send too fast then just slow down.
    Mailtrain to throttle sending emails to AWS SES
    Conclusion That s it! You re ready! Almost. You need an HTML template for your newsletter and a list of subscribers. Buf if you re not new in the newsletter field, fleeing Mailchimp because of their expensive prices, you should have them both already. After sending almost ten issues with this setup, I m really happy with it. Open/click rates are the same. When leaving Mailchimp, do not leave any list of subscribers because they ll charge you $8 for a 0 to 500 contacts, that s crazy expensive! About the author The post How to save up to 500 /year switching from Mailchimp to Open Source Mailtrain and AWS SES appeared first on Carl Chenet's Blog.

    Vincent Fourmond: Tutorial: analyze redox inactivations/reactivations

    Redox-dependent inactivations are actually rather common in the field of metalloenzymes, and electrochemistry can be an extremely powerful tool to study them, providing one can analyze the data quantitatively. The point of this point is to teach the reader how to do so using QSoas. For more general information about redox inactivations and how to study them using electrochemical techniques, the reader is invited to read the review del Barrio and Fourmond, ChemElectroChem 2019. This post is a tutorial to learn the analysis of data coming from the study of the redox-dependent substrate inhibition of periplasmic nitrate reductase NapAB, which has the advantage of being relatively simple. The whole processed is discussed in Jacques et al, BBA, 2014. What you need to know in order to follow this tutorial is the following: You can download the data files from the GitHub repository. Before fitting the data to determine the values of the rate constants at the potentials of the experiment, we will first subtract the background current, assuming that the respective contributions of faradaic and non-faradaic currents is additive. Start QSoas, go to the directory where you saved the files, and load both the data file and the blank file thus:
    QSoas> cd
    QSoas> load 27.oxw
    QSoas> load 27-blanc.oxw
    QSoas> S 1 0
    
    (after the first command, you have to manually select the directory in which you downloaded the data files). The S 1 0 command just subtracts the dataset 1 (the first loaded) from the dataset 0 (the last loaded), see more there. blanc is the French for blank... Then, we remove a bit of the beginning and the end of the data, corresponding to one half of the steps at \(E_0\), which we don't exploit much here (they are essentially only used to make sure that the irreversible loss is taken care of properly). This is done using strip-if:
    QSoas> strip-if x<30 x>300
    
    Then, we can fit ! The fit used is called fit-linear-kinetic-system, which is used to fit kinetic models with only linear reactions (like here) and steps which change the values of the rate constants but do not instantly change the concentrations. The specific command to fit the data is:
    QSoas> fit-linear-kinetic-system /species=2 /steps=0,1,2,1,0
    
    The /species=2 indicates that there are two species (A and I). The /steps=0,1,2,1,0 indicates that there are 5 steps, with three different conditions (0 to 2) in order 0,1,2,1,0. This fits needs a bit of setup before getting started. The species are numbered, 1 and 2, and the conditions (potentials) are indicated by #0, #1 and #2 suffixes. For the sake of simplicity, you can also simply load the starting-parameters.params parameters to have all setup the correct way. Then, just hit Fit, enjoy this moment when QSoas works and you don't have to... The screen should now look like this:
    Now, it's done ! The fit is actually pretty good, and you can read the values of the inactivation and reactivation rate constants from the fit parameters. You can train also on the 21.oxw and 21-blanc.oxw files. Usually, re-loading the best fit parameters from other potentials as starting parameters work really well. Gathering the results of several fits into a real curve of rate constants as a function of potentials is left as an exercise for the reader (or maybe a later post), although you may find these series of posts useful in this context !
    About QSoas QSoas is a powerful open source data analysis program that focuses on flexibility and powerful fitting capacities. It is released under the GNU General Public License. It is described in Fourmond, Anal. Chem., 2016, 88 (10), pp 5050 5052. Current version is 3.0. You can download its source code there (or clone from the GitHub repository) and compile it yourself, or buy precompiled versions for MacOS and Windows there.

    Next.

    Previous.