Search Results: "cas"

26 June 2021

Bastian Venthur: The State of Python Packaging in 2021

Every year or so, I revisit the current best practices for Python packaging. I.e. the way you re supposed to distribute your Python packages. The main source is packaging.python.org where the official packaging guidelines are. It is worth noting that the way you re supposed to package your Python applications is not defined by Python or its maintainers, but rather delegated to a separate entity, the Python Packaging Authority (PyPA). PyPA PyPA does an excellent job providing us with information, best practices and tutorials regarding Python packaging. However, there s one thing that irritates me every single time I revisit the page and that is the misleading recommendation of their own tool pipenv. Quoting from the tool recommendations section of the packaging guidelines:
Use Pipenv to manage library dependencies when developing Python applications. See Managing Application Dependencies for more details on using pipenv.
PyPA recommends pipenv as the standard tool for dependency management, at least since 2018. A bold statement, given that pipenv only started in 2017, so the Python community cannot have had not enough time to standardize on the workflow around that tool. There have been no releases of pipenv between 2018-11 and 2020-04, that s 1.5 years for the standard tool. In the past, pipenv also hasn t been shy in pushing breaking changes in a fast-paced manner. PyPA still advertises pipenv all over the place and only mentions poetry a couple of times, although poetry seems to be the more mature product. I understand that pipenv lives under the umbrella of PyPA, but I still expect objectiveness when it comes to tool recommendation. Instead of making such claims, they should provide a list of competing tools and provide a fair feature comparison. Distributions You would expect exactly one distribution for Python packages, but here in Python land, we have several ones. The most popular ones being PyPI the official one and Anaconda. Anaconda is more geared towards data-scientists. The main selling point for Anaconda back then was that it provided pre-compiled binaries. This was especially useful for data-science related packages which depend on libatlas, -lapack, -openblas, etc. and need to be compiled for the target system. This problem has mostly been solved with the wide adoption of wheels, but you still encounter some source-only uploads to PyPI that require you to build stuff locally on pip install. Of course there s also the Python packages distributed by the Operating System, Debian in my case. While I was a firm believer in only using those packages provided by the OS in the very past, I moved to the opposite end of the spectrum throughout the years, and am only using the minimal packages provided by Debian to bootstrap my virtual environments (i.e. pip, setuptools and wheel). The main reason is outdated or missing libraries, which is expected Debian cannot hope to keep up with all the upstream changes in the ecosystem, and that is by design and fine. However, with the recent upgrade of manylinux, even the pip provided by Debian/unstable was too outdated, so you basically had to pip install --upgrade pip for a while otherwise you d end up compiling every package you d try to install via pip. So I m sticking to the official PyPI distribution wherever possible. However, compared to the Debian distribution it feels immature. In my opinion, there should be compiled wheels for all packages available that need it, built and provided by PyPI. Currently, the wheels provided are the ones uploaded by the upstream maintainers. This is not enough, as they usually build wheels only for one platform. Sometimes they don t upload wheels in the first place, relying on the users to compile during install. Then you have manylinux, an excellent idea to create some common ground for a portable Linux build distribution. However, sometimes when a new version of manylinux is released some upstream maintainers immediately start supporting only that version, breaking a lot of systems. A setup similar to Debian s where the authors only do a source-upload and the wheels are compiled on PyPI infrastructure for all available platforms, is probably the way to go. setup.py, setup.cfg, requirements.txt. Pipfile, pyproject.toml oh my! This is the part I m revisiting the documentation every year, to see what s the current way to go. The main point of packaging your Python application is to define the package s meta data and (build-) dependencies. setup.py + requirements.txt For the longest time, the setup.py and requirements.txt were (and, spoiler alert: still is) the backbone of your packaging efforts. In setup.py you define the meta data of your package, including its dependencies. If your project is a deployable application (vs. a library) you ll very often provide an additional requirements.txt with pinned dependencies. Usually the list of requirements is the same as defined in setup.py but with pinned versions. The reason why you avoid version pinning in setup.py is that it would interfere with other pinned dependencies from other dependencies you try to install. setup.cfg setup.cfg is a configuration file that is used by many standard tools in the Python ecosystem. Its format is ini-style and each tools configuration lives in its own stanza. Since 2016 setuptools supports configuring setup() using setup.cfg files. This was exciting news back then, however, it does not completely replace the setup.py file. While you can move most of the setup.py configuration into setup.cfg, you ll still have to provide that file with an empty setup() in order to allow for editable pip installs. In my opinion, that makes this feature useless and I rather stick to setup.py with a properly populated setup() until that file can be completely replaced with something else. Pipfile + Pipflie.lock Pipfile and Pipfile.lock are supposed to replace requirements.txt some day. So far they are not supported by pip or mentioned in any PEP. I think only pipenv supports them, so I d ignore them for now. pyproject.toml PEP 518 introduces the pyproject.toml file as a way to specify build requirements for your project. PEP 621 defines how to store project meta data in it. pip and setuptools support pyproject.toml to some extent, but not to a point where it completely replaces setup.py yet. Many of Python s standard tools allow already for configuration in pyproject.toml so it seems this file will slowly replace the setup.cfg and probably setup.py and requirements.txt as well. But we re not there yet. poetry has an interesting approach: it will allow you to write everything into pyproject.toml and generate a setup.py for you at build-time, so it can be uploaded to PyPI. Ironically, Python settled for the TOML file format here, although there is currently no support for reading TOML files in Python s standard library. Summary While some alternatives exist, in 2021 I still stick to setup.py and requirements.txt to define the meta data and dependencies of my projects. Regarding the tooling, pip and twine are sufficient and do their job just fine. Alternatives like pipenv and poetry exist. The scope of poetry seems to be better aligned with my expectations, and it seems the more mature project compared to pipenv but in any case I ll ignore both of them until I revisit this issue in 2022. Closing Thoughts While the packaging in Python has improved a lot in the last years, I m still somewhat put off how such a core aspect of a programming language is treated within Python. With some jealousy, I look over to the folks at Rust and how they seemed to get this aspect right from the start. What would in my opinion improve the situation?

21 June 2021

Shirish Agarwal: Accessibility, Freenode and American imperialism.

Accessibility This is perhaps one of the strangest ways and yet also perhaps the straightest way to start the blog post. For the past weeks/months, a strange experience has been there. I am using a Logitech wireless keyboard and mouse for almost a decade. Now, for the past few months and weeks we observed a somewhat rare phenomena . While in-between us we have a single desktop computer. So me and mum take turns to be on the Desktop. At times, however, the system would sit idle and after some time it goes to low-power mode/sleep mode after 30 minutes. Then, when you want to come back, you obviously have to give your login credentials. At times, the keyboard refuses to input any data in the login screen. Interestingly, the mouse still functions. Much more interesting is the fact that both the mouse and the keyboard use the same transceiver sensor to send data. And I had changed batteries to ensure it was not a power issue but still no input :(. While my mother uses and used the power switch (I did teach her how to hold it for few minutes and then let it go) but for self, tried another thing. Using the mouse I logged of the session thinking perhaps some race condition or something might be in the session which was not letting the keystrokes be inputted into the system and having a new session might resolve it. But this was not to be  Luckily, on the screen you do have the option to reboot or power off. I did a reboot and lo, behold the system was able to input characters again. And this has happened time and again. I tried to find GOK and failed to remember that GOK had been retired. I looked up the accessibility page on Debian wiki. Very interesting, very detailed but sadly it did not and does not provide the backup I needed. I tried out florence but found that the app. is buggy. Moreover, the instructions provided on the lightdm screen does not work. I do not get the on-screen keyboard while I followed the instructions. Just to be clear this is all on Debian testing which is gonna be Debian stable soonish  I even tried the same with xvkbd but no avail. I do use mate as my desktop-manager so maybe the instructions need some refinement ???? $ cat /etc/lightdm/lightdm-gtk-greeter.conf grep keyboard
# a11y-states = states of accessibility features: name save state on exit, -name
disabled at start (default value for unlisted), +name enabled at start. Allowed names: contrast, font, keyboard, reader.
keyboard=xvkbd no-gnome focus &
# keyboard-position = x y[;width height] ( 50%,center -0;50% 25% by default) Works only for onboard
#keyboard= Interestingly, Debian does provide two more on-screen keyboards, matchbox as well as onboard which comes from Ubuntu. While I have both of them installed. I find xvkbd to be enough for my work, the only issue seems to be I cannot get it from the drop-down box of accessibility at the login screen. Just to make sure that I have not gone to Gnome-display manager, I did run

$ sudo dpkg-reconfigure gdm3 Only to find out that I am indeed running lightdm. So I am a bit confused why it doesn t come up as an option when I have the login window/login manager running. FWIW I do run metacity as the window manager as it plays nice with all the various desktop environments I have, almost all of them. So this is where I m stuck. If I do get any help, I probably would also add those instructions to the wiki page, so it would be convenient to the next person who comes with the same issue. I also need to figure out some way to know whether there is some race-condition or something which is happening, have no clue how would I go about it without having whole lot of noise. I am sure there are others who may have more of an idea. FWIW, I did search unix.stackexchange as well as reddit/debian to see if I could see any meaningful posts but came up empty.

Freenode I had not been using IRC for quite some time now. The reasons have been multiple issues with Riot (now element) taking the whole space on my desktop. I did get alerted to the whole thing about a week after the whole thing went down. Somebody messaged me DM. I *think* I put up a thread or a mini-thread about IRC or something in response to somebody praising telegram/WhatsApp or one of those apps. That probably triggered the DM. It took me a couple of minutes to hit upon this. I was angry and depressed, seeing the behavior of the new overlords of freenode. I did see that lot of channels moved over to Libera. It was also interesting to see that some communities were thinking of moving to some other obscure platform, which again could be held hostage to the same thing. One could argue one way or the other, but that would be tiresome and fact is any network needs lot of help to be grown and nurtured, whether it is online or offline. I also saw that Libera was also using a software Solanum which is ircv3 compliant. Now having done this initial investigation, it was time to move to an IRC client. The Libera documentation is and was pretty helpful in telling which IRC clients would be good with their network. So I first tried hexchat. I installed it and tried to add Libera server credentials, it didn t work. Did see that they had fixed the bug in sid/unstable and now it s in testing. But at the time it was in sid, the bug-fixed and I wanted to have something which just ran the damn thing. I chanced upon quassel. I had played around with quassel quite a number of times before, so I knew I could play/use it. Hence, I installed it and was able to use it on the first try. I did use the encrypted server and just had to tweak some settings before I could use it with some help with their documentation. Although, have to say that even quassel upstream needs to get its documentation in order. It is just all over the place, and they haven t put any effort into streamlining the documentation, so that finding things becomes easier. But that can be said of many projects upstream. There is one thing though that all of these IRC clients lack. The lack of a password manager. Now till that isn t fixed it will suck because you need another secure place to put your password/s. You either put it on your desktop somewhere (insecure) or store it in the cloud somewhere (somewhat secure but again need to remember that password), whatever you do is extra work. I am sure there will be a day when authenticating with Nickserv will be an automated task and people can just get on talking on channels and figuring out how to be part of the various communities. As can be seen, even now there is a bit of a learning curve for both newbies and people who know a bit about systems to get it working. Now, I know there are a lot of things that need to be fixed in the anonymity, security place if I put that sort of hat. For e.g. wouldn t it be cool if either the IRC client or one of its add-on gave throwaway usernames and passwords. The passwords would be complex. This would make it easier who are paranoid about security and many do and would have. As an example we can see of Fuchs. Now if the gentleman or lady is working in a professional capacity and would come to know of their real identity and perceive rightly or wrongly the role of that person, it will affect their career. Now, should it? I am sure a lot of people would be divided on the issue. Personally, as far as I am concerned, I would say no because whether right or wrong, whatever they were doing they were doing on their own time. Not on company time. So it doesn t concern the company at all. If we were to let companies police the behavior outside the time, individuals would be in a lot of trouble. Although, have to say that is a trend that has been seen in companies that are firing people either on the left or right. A recent example that comes to mind is Emily Wilder who was fired by Associated Press. Interestingly, she was interviewed by Democracy now, and it did come out that she is a Jew. As can be seen and understood there is a lot of nuance to her story and not the way she was fired. It doesn t give a good taste in the mouth, but then getting fired nobody does. On few forums, people did share of people getting fired of their job because they were dancing (cops). Again, it all depends, for me again, hats off to anybody who feels like dancing or whatever because there are just so many depressing stories all around.

Banned and FOE On few forums I was banned because I was talking about Brexit and American imperialism, both of which are seem to ruffle a few feathers in quite a few places. For instance, many people for obvious reasons do not like this video

Now I m sorry I am not able to and have not been able to give invidious links for the past few months. The reason being invidious itself went through some changes and the changes are good and bad. For e.g. now you need to share your google id with a third-party which at least to my mind is not a good idea. But that probably is another story altogether and it probably will need its own place. Coming back to the video itself, this was shared by Anthony hazard and the Title is The Atlantic slave trade: What too few textbooks told you . I did see this video quite a few years ago and still find it hard to swallow that tens of millions of Africans were bought as slaves to the Americas, although to be fair it does start with the Spanish settlement in the land which would be called the U.S. but they bought slaves with themselves. They even got the American natives, i.e. people from different tribes which made up America at that point. One point to note is that U.S. got its independence on July 4, 1776 so all the people before that were called as European settlers for want of a better word. Some or many of these European settlers would be convicts who were sent from UK. But as shared in the article, that would only happen with U.S. itself is mature and open enough for that discussion. Going back to the original point though, these European or American settlers bought lot of slaves from Africa. The video does also shed some of the cruelty the Europeans or Americans did on the slaves, men and women in different ways. The most revelatory part though which I also forget many a times that because lot of people were taken from Africa and many of them men, it did lead to imbalances in the African societies not just in weddings but economics in general. It also developed a theory called Critical Race theory in which it tries to paint the Africans as an inferior race otherwise how would Christianity work where their own good book says All men are born equal . That does in part explain why the African countries are still so far behind their European or American counterparts. But Africa can still be proud as they are richer than us, yup India. Sadly, I don t think America is ready to have that conversation anytime soon or if ever. And if it were to do, it would have to out-do any truth and reconciliation Committee which the world has seen. A mere apology or two would not just cut it. The problems of America sadly are not limited to just Africans but the natives of the land, for e.g. the Lakota people. In 1868, they put a letter stating we will give the land back to the Lakota people forever, but then the gold rush happened. In 2007, when the Lakota stated their proposal for independence, the U.S. through its force denied. So much for the paper, it was written on. Now from what I came to know over the years, the American natives are called First nations . Time and time again the American Govt. has tried or been foul towards them. Some of the examples include The Yucca Mountain nuclear waste repository . The same is and was the case with The Keystone pipeline which is now dead. Now one could say that it is America s internal matter and I would fully agree but when they speak of internal matters of other countries, then we should have the same freedom. But this is not restricted to just internal matters, sadly. Since the 1950 s i.e. the advent of the cold war, America s foreign policy made Regime changes all around the world. Sharing some of the examples from the Cold War

Iran 1953
Guatemala 1954
Democratic Republic of the Congo 1960
Republic of Ghana 1966
Iraq 1968
Chile 1973
Argentina 1976
Afghanistan 1978-1980s
Grenada
Nicaragua 1981-1990
1. Destabilization through CIA assets
2. Arming the Contras
El Salvador 1980-92
Philippines 1986 Even after the Cold War ended the situation was anonymolus, meaning they still continued with their old behavior. After the end of Cold War

Guatemala 1993
Serbia 2000
Iraq 2003-
Afghanistan 2001 ongoing There is a helpful Wikipedia article titled History of CIA which basically lists most of the covert regime changes done by U.S. The abvoe is merely a sub-set of the actions done by U.S. Now are all the behaviors above of a civilized nation ? And if one cares to notice, one would notice that all the above countries in the list which had the regime change had either Oil or precious metals. So U.S. is and was being what it accuses China, a profiteer. But this isn t just the U.S. China story but more about the American abuse of its power. My own country, India paid IMF loans till 1991 and we paid through the nose. There were economic sanctions against India. But then, this is again not just about U.S. India. Even with Europe or more precisely Norway which didn t want to side with America because their intelligence showed that no WMD were present in Iraq, the relationship still has issues.

Pandemic and the World So I do find that this whole blaming of China by U.S. quite theatrical and full of double-triple standards. Very early during the debates, it came to light that the Spanish Flu actually originated in Kensas, U.S.

What was also interesting as I found in the Pentagon Papers much before The Watergate scandal came out that U.S. had realized that China would be more of a competitor than Russia. And this itself was in 1960 s itself. This shows the level of intelligence that the Americans had. From what I can recollect from whatever I have read of that era, China was still mostly an agri-based economy. So, how the U.S. was able to deduce that China will surpass other economies is beyond me even now. They surely must have known something that even we today do not. One of the other interesting observations and understanding that I got while researching that every year we transfer an average of 7500 diseases from animal to humans and that should be a scary figure. I think more than anything else, loss of habitat and use of animals from food to clothing to medicine is probably the reason we are getting such diseases. I am also sure that there probably are and have been similar number of transfer of diseases from humans to animals as well but for well-known biases and whatnot those studies are neither done or are under-funded. There are and have been reports of something like 850,000 undiscovered viruses which various mammals and birds have. Also I did find that most of such pandemics are hard to identify, for e.g. SARS 1 took about 15 years, Ebola we don t know till date from where it came. Even HIV has questions for us. Hell, even why does hearing go away is a mystery to us. In all of this, we want to say China is culpable. And while China may or may not be culpable, only time will tell, this is surely the opportunity for all countries to spend and make capacities in public health. Countries which will take lessons from it and improve their public healthcare models will hopefully will not suffer as those who will suffer and are continuing to suffer now  To those who feel that habitat loss of animals is untrue, I would suggest them to see Sherni which depicts the human/animal conflict in all its brutality. I am gonna warn in advance that the ending is not nice but what can you expect from a country in which forest area cover has constantly declined and the Govt. itself is only interested in headline management

The only positive story I can share from India is that finally the Modi Govt. has said we will do free vaccine immunization for everybody. Although the pace is nothing to write home about. One additional thing they relaxed was instead of going to Cowin or any other portal, people could simply walk in using their identity papers. Although, given the pace of vaccinations, it is going to take anywhere between 13-18 months or more depending on availability of vaccines.

Looking forward to all and any replies have a virtual keyboard, preferably xvkbd as that is good enough for my use-case.

Russ Allbery: Review: Demon Lord of Karanda

Review: Demon Lord of Karanda, by David Eddings
Series: The Malloreon #3
Publisher: Del Rey
Copyright: September 1988
Printing: February 1991
ISBN: 0-345-36331-0
Format: Mass market
Pages: 404
This is the third book of the Malloreon, which in turn is a sequel trilogy to The Belgariad. Eddings, unlike most series authors, does a great job of reminding you what's happening with prologues in each book, but you definitely do not want to start reading here. When we last left our heroes, they had been captured. (This is arguably a spoiler for King of the Murgos, but it's not much of one, nor one that really matters.) This turns out to be an opportunity to meet the Emperor of Mallorea, the empire from which their adversary Zandramas (and, from the earlier trilogy, the god Torak) comes. This goes much better than one might expect, continuing the trend in this series of showing the leaders of the enemy countries as substantially similar to the leaders of the supposedly good countries. This sounds like open-mindedness on Eddings's part, and I suppose it partly is. It's at least a change from the first series, in which the bad guys were treated more like orcs. But the deeper I read into this series, the more obvious how invested Eddings is in a weird sort of classism. Garion and the others get along with Zakath in part because they're all royalty, or at least run in those circles. They just disagree about how to be a good ruler (and not as much as one might think, or hope). The general population of any of the countries is rarely of much significance. Zakath is a bit more cynical than Garion and company and has his own agenda, but he's not able to overcome the strong conviction of this series that the Prophecy and the fight between the Child of Light and the Child of Dark is the only thing of importance that's going on, and other people matter only to the extent that they're involved in that story. When I first read these books as a teenager, I was one of the few who liked the second series and didn't mind that its plot was partly a rehash of the first. I found, and still find, the blatantness with which Eddings manipulates the plot by making prophecy a character in the novel amusing. What I had forgotten, however, was how much of a slog the middle of this series is. It takes about three quarters of this book before there are any significant plot developments, and that time isn't packed with interesting diversions. It's mostly the heroes having conversations with each other or with Zakath, being weirdly sexist, rehashing their personality quirks, or shrugging about horrific events that don't matter to them personally. The last is a reference to the plague that appears in this book, and which I had completely forgotten. To be fair to my memory, that's partly because none of the characters seem to care much about it either. They're cooling their heels in a huge city, a plague starts killing people, they give Zakath amazingly brutal and bloodthirsty advice to essentially set fire to all the parts of the city with infected people, and then they blatantly ignore all the restrictions on movement because, well, they're important unlike all those other people and have places to go. It's rather stunningly unempathetic under the best of circumstances and seems even more vile in a 2021 re-read. Eddings also manages to make Ce'Nedra even more obnoxious than she has been by turning her into a walking zombie with weird fits where she's obsessed with her child, and adding further problems (which would be a spoiler) on top of that. I have never been a Ce'Nedra fan (that Garion's marriage ever works at all appears to be by authorial decree), but in this book she's both useless and irritating while supposedly being a tragic figure. You might be able to tell that I'm running sufficiently low on patience for Eddings's character quirks that I'm losing my enthusiasm for re-reading this bit of teenage nostalgia. This is the third book of a five-book series, so while there's a climax of sorts just like there was in the third book of the Belgariad, it's a false climax. One of the secondary characters is removed, but nothing is truly resolved; the state of the plot isn't much different at the end of this book than it was at the start. And to get there, one has to put up with Garion being an idiot, Ce'Nedra being a basket case, the supposed heroes being incredibly vicious about a plague, and one character pretending to have an absolutely dreadful Irish accent for pages upon pages upon pages. (His identity is supposedly a mystery, but was completely obvious a hundred pages before Garion figured it out. Garion isn't the sharpest knife in the drawer.) The one redeeming merit to this series is the dry voice in Garion's head and the absurd sight of the prophecy telling all the characters what to do, and we barely get any of that in this book. When it wasn't irritating or offensive, it was just a waste of time. The worst book of the series so far. Followed by Sorceress of Darshiva. Rating: 3 out of 10

20 June 2021

Julian Andres Klode: Migrating away from apt-key

This is an edited copy of an email I sent to provide guidance to users of apt-key as to how to handle things in a post apt-key world. The manual page already provides all you need to know for replacing apt-key add usage:
Note: Instead of using this command a keyring should be placed directly in the /etc/apt/trusted.gpg.d/ directory with a descriptive name and either gpg or asc as file extension
So it s kind of surprising people need step by step instructions for how to copy/download a file into a directory. I ll also discuss the alternative security snakeoil approach with signed-by that s become popular. Maybe we should not have added signed-by, people seem to forget that debs still run maintainer scripts as root. Aside from this email, Debian users should look into extrepo, which manages curated external repositories for you.

Direct translation Assume you currently have:
wget -qO- https://myrepo.example/myrepo.asc   sudo apt-key add  
To translate this directly for bionic and newer, you can use:
sudo wget -qO /etc/apt/trusted.gpg.d/myrepo.asc https://myrepo.example/myrepo.asc
or to avoid downloading as root:
wget -qO-  https://myrepo.example/myrepo.asc   sudo tee -a /etc/apt/trusted.gpg.d/myrepo.asc
Older (and all) releases only support unarmored files with an extension .gpg. If you care about them, provide one, and use
sudo wget -qO /etc/apt/trusted.gpg.d/myrepo.gpg https://myrepo.example/myrepo.gpg
Some people will tell you to download the .asc and pipe it to gpg --dearmor, but gpg might not be installed, so really, just offer a .gpg one instead that is supported on all systems. wget might not be available everywhere so you can use apt-helper:
sudo /usr/lib/apt/apt-helper download-file https://myrepo.example/myrepo.asc /etc/apt/trusted.gpg.d/myrepo.asc
or, to avoid downloading as root:
/usr/lib/apt/apt-helper download-file https://myrepo.example/myrepo.asc /tmp/myrepo.asc && sudo mv /tmp/myrepo.asc /etc/apt/trusted.gpg.d

Pretending to be safer by using signed-by People say it s good practice to not use trusted.gpg.d and install the file elsewhere and then refer to it from the sources.list entry by using signed-by=<path to the file>. So this looks a lot safer, because now your key can t sign other unrelated repositories. In practice, security increase is minimal, since package maintainer scripts run as root anyway. But I guess it s better for publicity :) As an example, here are the instructions to install signal-desktop from signal.org. As mentioned, gpg --dearmor use in there is not a good idea, and I d personally not tell people to modify /usr as it s supposed to be managed by the package manager, but we don t have an /etc/apt/keyrings or similar at the moment; it s fine though if the keyring is installed by the package. You can also just add the file there as a starting point, and then install a keyring package overriding it (pretend there is a signal-desktop-keyring package below that would override the .gpg we added).
# NOTE: These instructions only work for 64 bit Debian-based
# Linux distributions such as Ubuntu, Mint etc.
# 1. Install our official public software signing key
wget -O- https://updates.signal.org/desktop/apt/keys.asc   gpg --dearmor > signal-desktop-keyring.gpg
cat signal-desktop-keyring.gpg   sudo tee -a /usr/share/keyrings/signal-desktop-keyring.gpg > /dev/null
# 2. Add our repository to your list of repositories
echo 'deb [arch=amd64 signed-by=/usr/share/keyrings/signal-desktop-keyring.gpg] https://updates.signal.org/desktop/apt xenial main'  \
  sudo tee -a /etc/apt/sources.list.d/signal-xenial.list
# 3. Update your package database and install signal
sudo apt update && sudo apt install signal-desktop
I do wonder why they do wget gpg --dearmor, pipe that into the file and then cat sudo tee it, instead of having that all in one pipeline. Maybe they want nicer progress reporting.

Scenario-specific guidance We have three scenarios: For system image building, shipping the key in /etc/apt/trusted.gpg.d seems reasonable to me; you are the vendor sort of, so it can be globally trusted. Chrome-style debs and repository config debs: If you ship a deb, embedding the sources.list.d snippet (calling it $myrepo.list) and shipping a $myrepo.gpg in /usr/share/keyrings is the best approach. Whether you ship that in product debs aka vscode/chromium or provide a repository configuration deb (let s call it myrepo-repo.deb) and then tell people to run apt update followed by apt install <package inside the repo> depends on how many packages are in the repo, I guess. Manual instructions (signal style): The third case, where you tell people to run wget themselves, I find tricky. As we see in signal, just stuffing keyring files into /usr/share/keyrings is popular, despite /usr supposed to be managed by the package manager. We don t have another dir inside /etc (or /usr/local), so it s hard to suggest something else. There s no significant benefit from actually using signed-by, so it s kind of extra work for little gain, though.

Addendum: Future work This part is new, just for this blog post. Let s look at upcoming changes and how they make things easier.

Bundled .sources files Assuming I get my merge request merged, the next version of APT (2.4/2.3.something) will do away with all the complexity and allow you to embed the key directly into a deb822 .sources file (which have been available for some time now):
Types: deb
URIs: https://myrepo.example/ https://myotherrepo.example/
Suites: stable not-so-stable
Components: main
Signed-By:
 -----BEGIN PGP PUBLIC KEY BLOCK-----
 .
 mDMEYCQjIxYJKwYBBAHaRw8BAQdAD/P5Nvvnvk66SxBBHDbhRml9ORg1WV5CvzKY
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Then you can just provide a .sources files to users, they place it into sources.list.d, and everything magically works Probably adding a nice apt add-source command for it I guess. Well, python-apt s aptsources package still does not support deb822 sources, and never will, we ll need an aptsources2 for that for backwards-compatibility reasons, and then port software-properties and other users to it.

OpenPGP vs aptsign We do have a better, tighter replacement for gpg in the works which uses Ed25519 keys to sign Release files. It s temporarily named aptsign, but it s a generic signer for single-section deb822 files, similar to signify/minisign. We believe that this solves the security nightmare that our OpenPGP integration is while reducing complexity at the same time. Keys are much shorter, so the bundled sources file above will look much nicer.

Russ Allbery: Review: The Magician's Nephew

Review: The Magician's Nephew, by C.S. Lewis
Illustrator: Pauline Baynes
Series: Chronicles of Narnia #6
Publisher: Collier Books
Copyright: 1955
Printing: 1978
ISBN: 0-02-044230-0
Format: Mass market
Pages: 186
The Magician's Nephew is the sixth book of the Chronicles of Narnia in the original publication order, but it's a prequel, set fifty years before The Lion, the Witch and the Wardrobe. It's therefore put first in the new reading order. I have always loved world-building and continuities and, as a comics book reader (Marvel primarily), developed a deep enjoyment of filling in the pieces and reconstructing histories from later stories. It's no wonder that I love reading The Magician's Nephew after The Lion, the Witch and the Wardrobe. The experience of fleshing out backstory with detail and specifics makes me happy. If that's also you, I recommend the order in which I'm reading these books. Reading this one first is defensible, though. One of the strongest arguments for doing so is that it's a much stronger, tighter, and better-told story than The Lion, the Witch and the Wardrobe, and therefore might start the series off on a better foot for you. It stands alone well; you don't need to know any of the later events to enjoy this, although you will miss the significance of a few things like the lamp post and you don't get the full introduction to Aslan. The Magician's Nephew is the story of Polly Plummer, her new neighbor Digory Kirke, and his Uncle Andrew, who fancies himself a magician. At the start of the book, Digory's mother is bed-ridden and dying and Digory is miserable, which is the impetus for a friendship with Polly. The two decide to explore the crawl space of the row houses in which they live, seeing if they can get into the empty house past Digory's. They don't calculate the distances correctly and end up in Uncle Andrew's workroom, where Digory was forbidden to go. Uncle Andrew sees this as a golden opportunity to use them for an experiment in travel to other worlds. MAJOR SPOILERS BELOW. The Magician's Nephew, like the best of the Narnia books, does not drag its feet getting started. It takes a mere 30 pages to introduce all of the characters, establish a friendship, introduce us to a villain, and get both of the kids into another world. When Lewis is at his best, he has an economy of storytelling and a grasp of pacing that I wish was more common. It's also stuffed to the brim with ideas, one of the best of which is the Wood Between the Worlds. Uncle Andrew has crafted pairs of magic rings, yellow and green, and tricks Polly into touching one of the yellow ones, causing her to vanish from our world. He then uses her plight to coerce Digory into going after her, carrying two green rings that he thinks will bring people back into our world, and not incidentally also observing that world and returning to tell Uncle Andrew what it's like. But the world is more complicated than he thinks it is, and the place where the children find themselves is an eerie and incredibly peaceful wood, full of grass and trees but apparently no other living thing, and sprinkled with pools of water. This was my first encounter with the idea of a world that connects other worlds, and it remains the most memorable one for me. I love everything about the Wood: the simplicity of it, the calm that seems in part to be a defense against intrusion, the hidden danger that one might lose one's way and confuse the ponds for each other, and even the way that it tends to make one lose track of why one is there or what one is trying to accomplish. That quiet forest filled with pools is still an image I use for infinite creativity and potential. It's quiet and nonthreatening, but not entirely inviting either; it's magnificently neutral, letting each person bring what they wish to it. One of the minor plot points of this book is that Uncle Andrew is wrong about the rings because he's wrong about the worlds. There aren't just two worlds; there are an infinite number, with the Wood as a nexus, and our reality is neither the center nor one of an important pair. The rings are directional, but relative to the Wood, not our world. The kids, who are forced to experiment and who have open minds, figure this out quickly, but Uncle Andrew never shifts his perspective. This isn't important to the story, but I've always thought it was a nice touch of world-building. Where this story is heading, of course, is the creation of Narnia and the beginning of all of the stories told in the rest of the series. But before that, the kids's first trip out of the Wood is to one of the best worlds of children's fantasy: Charn. If the Wood is my mental image of a world nexus, Charn will forever be my image of a dying world: black sky, swollen red sun, and endless abandoned and crumbling buildings as far as the eye can see, full of tired silences and eerie noises. And, of course, the hall of statues, with one of the most memorable descriptions of history and empire I've ever read (if you ignore the racialized description):
All of the faces they could see were certainly nice. Both the men and women looked kind and wise, and they seemed to come of a handsome race. But after the children had gone a few steps down the room they came to faces that looked a little different. These were very solemn faces. You felt you would have to mind your P's and Q's, if you ever met living people who looked like that. When they had gone a little farther, they found themselves among faces they didn't like: this was about the middle of the room. The faces here looked very strong and proud and happy, but they looked cruel. A little further on, they looked crueller. Further on again, they were still cruel but they no longer looked happy. They were even despairing faces: as if the people they belonged to had done dreadful things and also suffered dreadful things.
The last statue is of a fierce, proud woman that Digory finds strikingly beautiful. (Lewis notes in an aside that Polly always said she never found anything specially beautiful about her. Here, as in The Silver Chair, the girl is the sensible one and things would have gone better if the boy had listened to her, a theme that I find immensely frustrating because Susan was the sensible one in the first two books of the series but then Lewis threw that away.) There is a bell in the middle of this hall, and the pillar that holds that bell has an inscription on it that I think every kid who grew up on Narnia knows by heart.
Make your choice, adventurous Stranger;
Strike the bell and bide the danger,
Or wonder, till it drives you mad,
What would have followed if you had.
Polly has no intention of striking the bell, but Digory fights her and does it anyway, waking Jadis from where she sat as the final statue in the hall and setting off one of the greatest reimaginings of a villain in children's literature. Jadis will, of course, become the White Witch who holds Narnia in endless winter some thousand Narnian years later. But the White Witch was a mediocre villain at best, the sort of obvious and cruel villain common in short fairy tales where the author isn't interested in doing much characterization. She exists to be evil, do bad things, and be defeated. She has a few good moments in conflict with Aslan, but that's about it. Jadis in this book is another matter entirely: proud, brilliant, dangerous, and creative. The death of everything on Charn was Jadis's doing: an intentional spell, used to claim a victory of sorts from the jaws of defeat by her sister in a civil war. (I find it fascinating that Lewis puts aside his normally sexist roles here.) Despite the best attempts of the kids to lose her both in Charn and in the Wood (which is inimical to her, in another nice bit of world-building), she manages to get back to England with them. The result is a remarkably good bit of villain characterization. Jadis is totally out of her element, used to a world-spanning empire run with magic and (from what hints we get) vaguely medieval technology. Her plan to take over their local country and eventually the world should be absurd and is played somewhat for laughs. Her magic, which is her great weapon, doesn't even work in England. But Jadis learns at a speed that the reader can watch. She's observant, she pays attention to things that don't fit her expectations, she changes plans, and she moves with predatory speed. Within a few hours in London she's stolen jewels and a horse and carriage, and the local police seem entirely overmatched. There's no way that one person without magic should be a real danger to England around the turn of the 20th century, but by the time the kids manage to pull her back into the Wood, you're not entirely sure England would have been safe. A chaotic confrontation, plus the ability of the rings to work their magic through transitive human contact, ends up with the kids, Uncle Andrew, Jadis, a taxicab driver and his horse all transported through the Wood to a new world. In this case, literally a new world: Narnia at the point of its creation. Here again, Lewis translates Christian myth, in this case the Genesis creation story, into a more vivid and in many ways more beautiful story than the original. Aslan singing the world into existence is an incredible image, as is the newly-created world so bursting with life that even things that normally could not grow will do so. (Which, of course, is why there is a lamp post burning in the middle of the western forest of Narnia for the Pevensie kids to find later.) I think my favorite part is the creation of the stars, but the whole sequence is great. There's also an insightful bit of human psychology. Uncle Andrew can't believe that a lion is singing, so he convinces himself that Aslan is not singing, and thus prevents himself from making any sense of the talking animals later.
Now the trouble about trying to make yourself stupider than you really are is that you very often succeed.
As with a lot in Lewis, he probably meant this as a statement about faith, but it generalizes well beyond the religious context. What disappointed me about the creation story, though, is the animals. I didn't notice this as a kid, but this re-read has sensitized me to how Lewis consistently treats the talking animals as less than humans even though he celebrates them. That happens here too: the newly-created, newly-awakened animals are curious and excited but kind of dim. Some of this is an attempt to show that they're young and are just starting to learn, but it also seems to be an excuse for Aslan to set up a human king and queen over them instead of teaching them directly how to deal with the threat of Jadis who the children inadvertently introduced into the world. The other thing I dislike about The Magician's Nephew is that the climax is unnecessarily cruel. Once Digory realizes the properties of the newly-created world, he hopes to find a way to use that to heal his mother. Aslan points out that he is responsible for Jadis entering the world and instead sends him on a mission to obtain a fruit that, when planted, will ward Narnia against her for many years. The same fruit would heal his mother, and he has to choose Narnia over her. (It's a fairly explicit parallel to the Garden of Eden, except in this case Digory passes.) Aslan, in the end, gives Digory the fruit of the tree that grows, which is still sufficient to heal his mother, but this sequence made me angry when re-reading it. Aslan knew all along that what Digory is doing will let him heal his mother as well, but hides this from him to make it more of a test. It's cruel and mean; Aslan could have promised to heal Digory's mother and then seen if he would help Narnia without getting anything in return other than atoning for his error, but I suppose that was too transactional for Lewis's theology or something. Meh. But, despite that, the only reason why this is not the best Narnia book is because The Voyage of the Dawn Treader is the only Narnia book that also nails the ending. The Magician's Nephew, up through Charn, Jadis's rampage through London, and the initial creation of Narnia, is fully as good, perhaps better. It sags a bit at the end, partly because it tries to hard to make the Narnian animals humorous and partly because of the unnecessary emotional torture of Digory. But this still holds up as the second-best Narnia book, and one I thoroughly enjoyed re-reading. If anything, Jadis and Charn are even better than I remembered. Followed by the last book of the series, the somewhat notorious The Last Battle. Rating: 9 out of 10

Sean Whitton: transient-caps-lock

If you re writing a lot of Common Lisp and you want to follow the convention of using all uppercase to refer to symbols in docstrings, comments etc., you really need something better than the shift key. Similarly if you re writing C and you have VARIOUS_LONG_ENUMS. The traditional way is a caps lock key. But that means giving up a whole keyboard key, all of the time, just for block capitalisation, which one hardly uses outside of programming. So a better alternative is to come up with some Emacs thing to get block capitalisation, as Emacs key binding is much more flexible than system keyboard layouts, and can let us get block capitalisation without giving up a whole key. The simplest thing would be to bind some sequence of keys to just toggle caps lock. But I came up with something a bit fancier. With the following, you can type M-C, and then you get block caps until the point at which you ve probably finished typing your symbol or enum name.
(defun spw/transient-caps-self-insert (&optional n)
  (interactive "p")
  (insert-char (upcase last-command-event) n))
(defun spw/activate-transient-caps ()
  "Activate caps lock while typing the current whitespace-delimited word(s).
This is useful for typing Lisp symbols and C enums which consist
of several all-uppercase words separated by hyphens and
underscores, such that M-- M-u after typing will not upcase the
whole thing."
  (interactive)
  (let* ((map (make-sparse-keymap))
     (deletion-commands &apos(delete-backward-char
                          paredit-backward-delete
                          backward-kill-word
                          paredit-backward-kill-word
                          spw/unix-word-rubout
                          spw/paredit-unix-word-rubout))
     (typing-commands (cons &aposspw/transient-caps-self-insert
                            deletion-commands)))
     (substitute-key-definition &aposself-insert-command
                                #&aposspw/transient-caps-self-insert
                                map
                                (current-global-map))
    (set-transient-map
     map
     (lambda ()
       ;; try to determine whether we are probably still about to try to type
       ;; something in all-uppercase
       (and (member this-command typing-commands)
            (not (and (eq this-command &aposspw/transient-caps-self-insert)
                      (= (char-syntax last-command-event) ?\ )))
            (not (and (or (bolp) (= (char-syntax (char-before)) ?\ ))
                      (member this-command deletion-commands))))))))
(global-set-key "\M-C" #&aposspw/activate-transient-caps)
A few notes:

19 June 2021

Chris Lamb: *Raiders of the Lost Ark*: 40 Years On

"Again, we see there is nothing you can possess which I cannot take away."
The cinema was a rare and expensive treat in my youth, so I first came across Raiders of the Lost Ark by recording it from television onto a poor quality VHS. I only mention this as it meant I watched a slightly different film to the one intended, as my copy somehow missed off the first 10 minutes. For those not as intimately familiar with the film as me, this is just in time to see a Belloq demand Dr. Jones hand over the Peruvian head (see above), just in time to learn that Indy loathes snakes, and just in time to see the inadvertent reproduction of two Europeans squabbling over the spoils of a foreign land. What this truncation did to my interpretation of the film (released thirty years ago today on June 19th 1981) is interesting to explore. Without Jones' physical and moral traits being demonstrated on-screen (as well as missing the weighing the gold head and the rollercoaster boulder scene), it actually made the idea of 'Indiana Jones' even more of a mythical archetype. The film wisely withholds Jones' backstory, but my directors cut deprived him of even more, and counterintuitively imbued him with even more of a legendary hue as the elision made his qualities an assumption beyond question. Indiana Jones, if you can excuse the clich , needed no introduction at all. Good artists copy, great artists steal. And oh boy, does Raiders steal. I've watched this film about twenty times over the past two decades and it's now firmly entered into my personal canon. But watching it on its thirtieth anniversary was different not least because I could situate it in a broader cinematic context. For example, I now see the Gestapo officer in Major Strasser from Casablanca (1942), in fact just as I can with many of Raiders' other orientalist tendencies: not only in its breezy depictions of backwards sand people, but also of North Africa as an entrep t and playground for a certain kind of Western gangster. The opening as well, set in an equally reductionist pseudo-Peru, now feels like Werner Herzog's Aguirre, the Wrath of God (1972) but without, of course, any self-conscious colonial critique.
The imagery of the ark appears to be borrowed from James Tissot's The Ark Passes Over the Jordan, part of the fin de siecle fascination with the occult and (ironically enough given the background of Raiders' director), a French Catholic revival.
I can now also appreciate some of the finer edges that make this film just so much damn fun to watch. For instance, the comic book conceit that Jones and Belloq are a 'shadowy reflection' of one other and that they need 'only a nudge' to make one like the other. As is the idea that Belloq seems to be actually enjoying being evil. I also spotted Jones rejecting the martini on the plane. This feels less like a comment on corrupting effect of alcohol (he drinks rather heavily elsewhere in the film), but rather a subtle distancing from James Bond. This feels especially important given that the action-packed cold open is, let us be honest for a second, ripped straight from the 007 franchise. John William's soundtracks are always worth mentioning. The corny Raiders March does almost nothing for me, but the highly-underrated 'Ark theme' certainly does. I delight in its allusions to Gregorian chant, the diabolus in musica and the Hungarian minor scale, fusing the Christian doctrine of the Holy Trinity (the stacked thirds, get it?), the ars antiqua of the Middle Ages with an 'exotic' twist that the Russian Five associated with central European Judaism.
The best use of the ark leitmotif is, of course, when it is opened. Here, Indy and Marion are saved by not opening their eyes whilst the 'High Priest' Belloq and the rest of the Nazis are all melted away. I'm no Biblical scholar, but I'm almost certain they were alluding to Leviticus 16:2 here:
The Lord said to Moses: Tell your brother Aaron that he is not to come whenever he chooses into the Most Holy Place behind the curtain in front of the atonement cover on the ark, or else he will die, for I will appear in the cloud above the mercy seat.
But would it be too much of a stretch to also see the myth of Orpheus and Eurydices too? Orpheus's wife would only be saved from the underworld if he did not turn around until he came to his own house. But he turned round to look at his wife, and she instantly slipped back into the depths:
For he who overcome should turn back his gaze
Towards the Tartarean cave,
Whatever excellence he takes with him
He loses when he looks on those below.
Perhaps not, given that Marion and the ark are not lost in quite the same way. But whilst touching on gender, it was interesting to update my view of archaeologist Ren Belloq. To countermand his slight queer coding (a trope of Disney villains such as Scar, Jafar, Cruella, etc.), there is a rather clumsy subplot involving Belloq repeatedly (and half-heartedly) failing to seduce Marion. This disavows any idea that Belloq isn't firmly heterosexual, essential for the film's mainstream audience, but it is especially important in Raiders because, if we recall the relationship between Belloq and Jones: 'it would take only a nudge to make you like me'. (This would definitely put a new slant on 'Top men'.)
However, my favourite moment is where the Nazis place the ark in a crate in order to transport it to the deserted island. On route, the swastikas on the side of the crate spontaneously burn away, and a disturbing noise is heard in the background. This short scene has always fascinated me, partly because it's the first time in the film that the power of the ark is demonstrated first-hand but also because gives the object an other-worldly nature that, to the best of my knowledge, has no parallel in the rest of cinema. Still, I had always assumed that the Aak disfigured the swastikas because of their association with the Nazis, interpreting the act as God's condemnation of the Third Reich. But now I catch myself wondering whether the ark would have disfigured any iconography as a matter of principle or whether their treatment was specific to the swastika. We later get a partial answer to this question, as the 'US Army' inscriptions in the Citizen Kane warehouse remain untouched. Far from being an insignificant concern, the filmmakers appear to have wandered into a highly-contested theological debate. As in, if the burning of the swastika is God's moral judgement of the Nazi regime, then God is clearly both willing and able to intervene in human affairs. So why did he not, to put it mildly, prevent Auschwitz? From this perspective, Spielberg appears to be limbering up for some of the academic critiques surrounding Holocaust representations that will follow Schindler's List (1993). Given my nostalgic and somewhat ironic attachment to Raiders, it will always be difficult for me to objectively appraise the film. Even so, it feels like it is underpinned by an earnest attempt to entertain the viewer, largely absent in the affected cynicism of contemporary cinema. And when considered in the totality of Hollywood's output, its tonal and technical flaws are not actually that bad or at least Marion's muddled characterisation and its breezy chauvinism (for example) clearly have far worse examples. Perhaps the most remarkable thing about the film in 2021 is that it hasn't changed that much at all. It spawned one good sequel (The Last Crusade), one bad one (The Temple of Doom), and one hardly worth mentioning at all, yet these adventures haven't affected the original Raiders in any meaningful way. In fact, if anything has affected the original text it is, once again, George Lucas himself, as knowing the impending backlash around the Star Wars prequels adds an inadvertent paratext to all his earlier works. Yet in a 1978 discussion prior to the creation of Raiders, you can get a keen sense of how Lucas' childlike enthusiasm will always result in something either extremely good or something extremely bad somehow no middle ground is quite possible. Yes, it's easy to rubbish his initial ideas 'We'll call him Indiana Smith! but hasn't Lucas actually captured the essence of a heroic 'Americana' here, and that the final result is simply a difference of degree, not kind?

Chris Lamb: Raiders of the Lost Ark: 40 Years On

"Again, we see there is nothing you can possess which I cannot take away."
The cinema was a rare and expensive treat in my youth, so I first came across Raiders of the Lost Ark by recording it from television onto a poor quality VHS. I only mention this as it meant I watched a slightly different film to the one intended, as my copy somehow missed off the first 10 minutes. For those not as intimately familiar with the film as me, this is just in time to see a Belloq demand Dr. Jones hand over the Peruvian head (see above), just in time to learn that Indy loathes snakes, and just in time to see the inadvertent reproduction of two Europeans squabbling over the spoils of a foreign land. What this truncation did to my interpretation of the film (released thirty years ago today on June 19th 1981) is interesting to explore. Without Jones' physical and moral traits being demonstrated on-screen (as well as missing the weighing the gold head and the rollercoaster boulder scene), it actually made the idea of 'Indiana Jones' even more of a mythical archetype. The film wisely withholds Jones' backstory, but my directors cut deprived him of even more, and counterintuitively imbued him with even more of a legendary hue as the elision made his qualities an assumption beyond question. Indiana Jones, if you can excuse the clich , needed no introduction at all. Good artists copy, great artists steal. And oh boy, does Raiders steal. I've watched this film about twenty times over the past two decades and it's now firmly entered into my personal canon. But watching it on its thirtieth anniversary was different not least because I could situate it in a broader cinematic context. For example, I now see the Gestapo officer in Major Strasser from Casablanca (1942), in fact just as I can with many of Raiders' other orientalist tendencies: not only in its breezy depictions of backwards sand people, but also of North Africa as an entrep t and playground for a certain kind of Western gangster. The opening as well, set in an equally reductionist pseudo-Peru, now feels like Werner Herzog's Aguirre, the Wrath of God (1972) but without, of course, any self-conscious colonial critique.
The imagery of the ark appears to be borrowed from James Tissot's The Ark Passes Over the Jordan, part of the fin de siecle fascination with the occult and (ironically enough given the background of Raiders' director), a French Catholic revival.
I can now also appreciate some of the finer edges that make this film just so much damn fun to watch. For instance, the comic book conceit that Jones and Belloq are a 'shadowy reflection' of one other and that they need 'only a nudge' to make one like the other. As is the idea that Belloq seems to be actually enjoying being evil. I also spotted Jones rejecting the martini on the plane. This feels less like a comment on corrupting effect of alcohol (he drinks rather heavily elsewhere in the film), but rather a subtle distancing from James Bond. This feels especially important given that the action-packed cold open is, let us be honest for a second, ripped straight from the 007 franchise. John William's soundtracks are always worth mentioning. The corny Raiders March does almost nothing for me, but the highly-underrated 'Ark theme' certainly does. I delight in its allusions to Gregorian chant, the diabolus in musica and the Hungarian minor scale, fusing the Christian doctrine of the Holy Trinity (the stacked thirds, get it?), the ars antiqua of the Middle Ages with an 'exotic' twist that the Russian Five associated with central European Judaism.
The best use of the ark leitmotif is, of course, when it is opened. Here, Indy and Marion are saved by not opening their eyes whilst the 'High Priest' Belloq and the rest of the Nazis are all melted away. I'm no Biblical scholar, but I'm almost certain they were alluding to Leviticus 16:2 here:
The Lord said to Moses: Tell your brother Aaron that he is not to come whenever he chooses into the Most Holy Place behind the curtain in front of the atonement cover on the ark, or else he will die, for I will appear in the cloud above the mercy seat.
But would it be too much of a stretch to also see the myth of Orpheus and Eurydices too? Orpheus's wife would only be saved from the underworld if he did not turn around until he came to his own house. But he turned round to look at his wife, and she instantly slipped back into the depths:
For he who overcome should turn back his gaze
Towards the Tartarean cave,
Whatever excellence he takes with him
He loses when he looks on those below.
Perhaps not, given that Marion and the ark are not lost in quite the same way. But whilst touching on gender, it was interesting to update my view of archaeologist Ren Belloq. To countermand his slight queer coding (a trope of Disney villains such as Scar, Jafar, Cruella, etc.), there is a rather clumsy subplot involving Belloq repeatedly (and half-heartedly) failing to seduce Marion. This disavows any idea that Belloq isn't firmly heterosexual, essential for the film's mainstream audience, but it is especially important in Raiders because, if we recall the relationship between Belloq and Jones: 'it would take only a nudge to make you like me'. (This would definitely put a new slant on 'Top men'.)
However, my favourite moment is where the Nazis place the ark in a crate in order to transport it to the deserted island. On route, the swastikas on the side of the crate spontaneously burn away, and a disturbing noise is heard in the background. This short scene has always fascinated me, partly because it's the first time in the film that the power of the ark is demonstrated first-hand but also because gives the object an other-worldly nature that, to the best of my knowledge, has no parallel in the rest of cinema. Still, I had always assumed that the Aak disfigured the swastikas because of their association with the Nazis, interpreting the act as God's condemnation of the Third Reich. But now I catch myself wondering whether the ark would have disfigured any iconography as a matter of principle or whether their treatment was specific to the swastika. We later get a partial answer to this question, as the 'US Army' inscriptions in the Citizen Kane warehouse remain untouched. Far from being an insignificant concern, the filmmakers appear to have wandered into a highly-contested theological debate. As in, if the burning of the swastika is God's moral judgement of the Nazi regime, then God is clearly both willing and able to intervene in human affairs. So why did he not, to put it mildly, prevent Auschwitz? From this perspective, Spielberg appears to be limbering up for some of the academic critiques surrounding Holocaust representations that will follow Schindler's List (1993). Given my nostalgic and somewhat ironic attachment to Raiders, it will always be difficult for me to objectively appraise the film. Even so, it feels like it is underpinned by an earnest attempt to entertain the viewer, largely absent in the affected cynicism of contemporary cinema. And when considered in the totality of Hollywood's output, its tonal and technical flaws are not actually that bad or at least Marion's muddled characterisation and its breezy chauvinism (for example) clearly have far worse examples. Perhaps the most remarkable thing about the film in 2021 is that it hasn't changed that much at all. It spawned one good sequel (The Last Crusade), one bad one (The Temple of Doom), and one hardly worth mentioning at all, yet these adventures haven't affected the original Raiders in any meaningful way. In fact, if anything has affected the original text it is, once again, George Lucas himself, as knowing the impending backlash around the Star Wars prequels adds an inadvertent paratext to all his earlier works. Yet in a 1978 discussion prior to the creation of Raiders, you can get a keen sense of how Lucas' childlike enthusiasm will always result in something either extremely good or something extremely bad somehow no middle ground is quite possible. Yes, it's easy to rubbish his initial ideas 'We'll call him Indiana Smith! but hasn't Lucas actually captured the essence of a heroic 'Americana' here, and that the final result is simply a difference of degree, not kind?

Joachim Breitner: Leaving DFINITY

Last Thursday was my last working day at DFINITY. There are various reasons why I felt that after almost three years the DFINITY Foundation isn t quite the right place for me anymore, and this plan has been in the making for a while. Primarily, there are personal pull factors that strongly suggest that I ll take a break from full time employment, so I decided to see the launch of the Internet Computer through and then leave. DFINITY has hired some amazing people, and it was a great pleasure to work with them. I learned a lot (some Rust, a lot of Nix, and just how merciless Conway s law is), and I dare say I had the opportunity to do some good work, contributing my part to make the Internet Computer a reality. I am especially proud of the Interface Specification and the specification-driven design principles behind it. It even comes with a model reference implementation and acceptance test suite, and although we didn t quite get to do formalization, those familiar with the DeepSpec project will recognize some influence of their concept of deep specifications . Besides that, there is of course my work on the Motoko programming language, where I build the backend,a the Candid interoperability layer, where I helped with the formalism, formulated the a generic soundness criterion for Interface Description Languages in a higher order settings and formally verified that in Coq. Fortunately, all of this work is now Free Software or at least Open Source. With so much work poured into this project, I continue to care about it, and you ll see me post on the the developer forum and hack on Motoko. As the Internet Computer becomes gradually more open, I hope I can be gradually more involved again. But even without me contributing full-time I am sure that DFINITY and the Internet Computer will do well; when I left there were still plenty of smart, capable and enthusiastic people forging ahead. So what s next? So far, I have rushed every professional transition in my life: When starting my PhD, when starting my postdoc, when starting my job at DFINITY, and every time I regretted it. So this time, I will take a proper break and will explore the world a bit (as far as that is possible given the pandemic). I will stresslessly contribute to various open source projects. I also hope to do more public outreach and teaching, writing more blog posts again, recording screencasts and giving talks and lectures. If you want to invite me to your user group/seminar/company/workshop, please let me know! Also, I might be up for small interesting projects in a while. Beyond these, I have no concrete plans and am looking forward to the inspiration I might get from hiking through the Scandinavian wilderness. If you happen to stumble across my tent, please stop for a tea.

17 June 2021

Rapha&#235;l Hertzog: Submit your ideas for Debian and +1 those that you find important

A while ago, I got a request from Kentaro Hayashi on the project I use to manage funding requests addressed to Freexian. He was keen to see some improvements on the way reimbursement requests are handled in Debian. In my opinion, the idea is certainly good but he s not part of the treasurer team and was not willing to implement the project either, so it was not really ready to be submitted to us. To be able to fund a useful project, we need either someone that is willing to do the work and try to push it further in Debian, or we need a Debian team interested in the result of the project (and in that case, we can try to find someone willing to implement the project). In this case, it s a bit sad that the treasurer team didn t comment at all but in general, what should we do with those suggestions ? It would still be interesting to have a list of such suggestions and have Debian developers be able to advocate (+1) those suggestions. It s in this spirit that Kentaro created the Grow your ideas project on salsa.debian.org. Browse the list of issues, submit your own and click on  (+1) to bump the suggestions that you find interesting. And click on the Watch button on the homepage to receive notifications when others submit suggestions so that you can evaluate those suggestions and possibly improve them through your comments. In the end, this can only help those that are looking for ways to contribute to Debian: maybe some of them will formalize a concrete action plan and request funding for it! We have a pile of money sitting unused that s clearly targeted to pay contributors to improve our infrastructure. And we have endless lists of (wishlist) bugs on all our infrastructure projects (dak, distro-tracker, ). What are you waiting ?

Joey Hess: typed pipes in every shell

Powershell and nushell take unix piping beyond raw streams of text to structured or typed data. Is it possible to keep a traditional shell like bash and still get typed pipes? I think it is possible, and I'm now surprised noone seems to have done it yet. This is a fairly detailed design for how to do it. I've not implemented it yet. RFC. Let's start with a command called typed. You can use it in a pipeline like this:
typed foo   typed bar   typed baz
What typed does is discover the types of the commands to its left and its right, while communicating the type of the command it runs back to them. Then it checks if the types match, and runs the command, communicating the type information to it. Pipes are unidirectional, so it may seem hard to discover the type to the right, but I'll explain how it can be done in a minute. Now suppose that foo generates json, and bar filters structured data of a variety of types, and baz consumes csv and pretty-prints a table. Then bar will be informed that its input is supposed to be json, and that its output should be csv. If bar didn't support json, typed foo and typed bar would both fail with a type error. Writing "typed" in front of everything is annoying. But it can be made a shell alias like "t". It also possible to wrap programs using typed:
cat >~/bin/foo <<EOF
#/usr/bin/typed /usr/bin/foo
EOF
Or program could import a library that uses typed, so it natively supports being used in typed pipelines. I'll explain one way to make such a library later on, once some more details are clear. Which gets us back to a nice simple pipeline, now automatically typed.
foo   bar   baz
If one of the commands is not actually typed, the other ones in the pipe will treat it as having a raw stream of text as input or output. Which will sometimes result in a type error (yay, I love type errors!), but in other cases can do something useful.
find   bar   baz
# type error, bar expected json or csv
foo   bar   less
# less displays csv 
So how does typed discover the types of the commands to the left and right? That's the hard part. It has to start by finding the pids to its left and right. There is no really good way to do that, but on Linux, it can be done: Look at what /proc/self/fd/0 and /proc/self/fd/1 link to, which contains the unique identifiers of the pipes. Then look at other processes' fd/0 and fd/1 to find matching pipe identifiers. (It's also possible to do this on OSX, I believe. I don't know about BSDs.) Searching through all processes would be a bit expensive (around 15 ms with an average number of processes), but there's a nice optimisation: The shell will have started the processes close together in time, so the pids are probably nearby. So look at the previous pid, and the next pid, and fan outward. Also, check isatty to detect the beginning and end of the pipeline and avoid scanning all the processes in those cases. To indicate the type of the command it will run, typed simply opens a file with an extension of ".typed". The file can be located anywhere, and can be an already existing file, or can be created as needed (eg in /run). Once it discovers the pid at the other end of a pipe, typed first looks at /proc/$pid/cmdline to see if it's also running typed. If it is, it looks at its open file handles to find the first ".typed" file. It may need to wait for the file handle to get opened, which is why it needs to verify the pid is running typed. There also needs to be a way for typed to learn the type of the command it will run. Reading /usr/share/typed/$command.typed is one way. Or it can be specified at the command line, which is useful for wrapper scripts:
cat >~/bin/bar <<EOF
#/usr/bin/typed --type="JSON   CSV" --output-type="JSON   CSV" /usr/bin/bar
EOF
And typed communicates the type information to the command that it runs. This way a command like bar can know what format its input should be in, and what format to use as output. This might be done with environment variables, eg INPUT_TYPE=JSON and OUTPUT_TYPE=CSV I think that's everything typed needs, except for the syntax of types and how the type checking works. Which I should probably not try to think up off the cuff. I used Haskell ADT syntax in the example above, but don't think that's necessarily the right choice. Finally, here's how to make a library that lets a program natively support being used in a typed pipeline. It's a bit tricky, because it has to run typed, because typed checks /proc/$pid/cmdline as detailed above. So, check an environment variable. When not set yet, set it, and exec typed, passing it the path to the program, which it will re-exec. This should be done before program does anything else.
This work was sponsored by Mark Reidenbach on Patreon.

16 June 2021

Julien Danjou: Python Tools to Try in 2021

Python Tools to Try in 2021The Python programming language is one of the most popular and in huge demand. It is free, has a large community, is intended for the development of projects of varying complexity, is easy to learn, and opens up great opportunities for programmers. To work comfortably with it, you need special Python tools, which are able to simplify your work. We have selected the best Python tools that will be relevant in 2021.

MailtrapAs you may probably know, in order to send an email, you need SMTP (Simple Mail Transfer Protocol). This is because you can't just send a letter to the recipient. It needs to be sent to the server from which the recipient will download this letter using IMAP and POP3.Mailtrap provides an opportunity to send emails in python. Moreover, Mailtrap provides #rest #api to access current emails. It can be used to automate email testing, which will improve your email marketing campaigns. For example, you can check the password recovery form in the Selenium Test and immediately see if an email was sent to the correct address. Then take a new password from the email and try to enter the site with it. Cool, isn't it?

Pros
  • All emails are in one place.
  • Mailtrap provides multiple inboxes.
  • Shared access is present.
  • It is easy to set up.
  • RESTful API

ConsNo visible disadvantages were found.

Django
Python Tools to Try in 2021
Django is a free and open-source full-stack framework. It is one of the most important and popular among Python developers. It helps you move from a prototype to a ready-made working solution in a short time since its main task is to automate processes and speed up work through associations and libraries. It s a great choice for a product launch.You can use Django if at least a few of the following points interest you:
  • There is a need to develop the server-side of the API.
  • You need to develop a web application.
  • In the course of work, many changes are made, you have to constantly deploy the application and make edits.
  • There are many complex tasks that are difficult to solve on your own, and you will need the help of the community.
  • ORM support is needed to avoid accessing the database directly.
  • There is a need to integrate new technologies such as machine learning.
Django is a great Python Web Framework that does its job. It is not for nothing that it is one of the most popular, and is actively used by millions of developers.

ProsDjango has quite a few advantages. It contains a large number of ready-made solutions, which greatly simplifies development. Admin panel, database migration, various forms, user authentication tools are extremely helpful. The structure is very clear and simple.A large community helps to solve almost any problem. Thanks to ORM, there is a high level of security and it is comfortable to work with databases.

ConsDespite its powerful capabilities, Django's Python Web Framework has drawbacks. It is very massive, monolithic, therefore it develops slowly. Despite the many generic modules, the development speed of Django itself is reduced.

CherryPy
Python Tools to Try in 2021
CherryPy is a micro-framework. It is designed to solve specific problems, capable of running the program on any operating system. CherryPy is used in the following cases:
  • To create an application with small code size.
  • There is a need to manage several servers at the same time.
  • You need to monitor the performance of applications.
CherryPy refers to Python Frameworks, which are designed for specific tasks. It's clear, user-friendly, and ideal for Android development.

ProsCherryPy Python tool has a friendly and understandable development environment. This is a functional and complete framework, which can be used to build good applications. The source code is open, so the platform is completely free for developers, and the community, although not too large, is very responsive, and always helps to solve problems.

ConsThere are not so many cons to this Python tool. It is not capable of performing complex tasks and functions, it is intended more for specific solutions, for example, for the development of certain plugins or modules.

Pyramid
Python Tools to Try in 2021
Python Pyramid tool is designed for programming complex objects and solving multifunctional problems. It is used by professional programmers and is traditionally used for identification and routing. It is aimed at a wide audience and is capable of developing API prototypes.It is used in the following cases:
  • You need problem indicator tools to make timely adjustments and edits.
  • You use several programming languages at once;
  • You work with reporting and financial calculations, forecasting;
  • You need to quickly create a simple application.
At the same time, the Python Web Framework Pyramid allows you to create complex applications with great functionality like a translation software.

ProsPyramid does an excellent job of developing basic applications quickly. It is quite flexible and easy to learn. In fact, the key to the success of this framework is that it is completely based on fundamental principles, using simple and basic programming techniques. It is minimalistic, but at the same time offers users a lot of freedom of action. It is able to work with both small applications and powerful multifunctional programs.

ConsIt is difficult to deviate from the basic principles. This Python tool makes the decision for you. Simple programs are very easy to implement. But to do something complex and large-scale, you have to completely immerse yourself in the study of the environment and obey it.

Grok
Python Tools to Try in 2021
Grok is a Python tool that works with templates. Its main task is to eliminate repetitions in the code. If the element is repeated, then the template that was already created earlier is simply applied. This greatly simplifies and speeds up the work.Grok suits developers in the following cases:
  • If a programmer has little experience and is not yet ready to develop his modules.
  • There is a need to quickly develop a simple application.
  • The functionality of the application is simple, straightforward, and the interface does not play a key role.

ProsThe Grok framework is a child of Zope3, which was released earlier. It has a simplified structure of work, easy installation of modules, more capabilities, and better flexibility. It is designed to develop small applications. Yes, it is not intended for complex work, but due to its functionality, it allows you to quickly implement a project.

ConsThe Grok community is not very large, as this Python tool has not gained widespread popularity. Nevertheless, it is used by Python adepts for comfortable development. It is impossible to implement complex tasks on it since the possibilities are quite limited.Grok is one of the best Python Web Frameworks. It is understandable and has enough features for comfortable development.

Web2Py
Python Tools to Try in 2021
Web2Py is a Python tool that has its own IDEwhich, which includes a code editor, debugger, and deployment. It works great without the need for configuration or installation, provides a high level of data security, and is suitable for work on various platforms.Web2Py is great in the following cases:
  • When there is a need to develop something on different operating systems.
  • If there is no way to install and configure the framework.
  • When a high level of data security is required, for example, when developing financial applications or sales performance management tools.
  • If you need to carefully track bugs right during development, and not during the testing phase.

ProsWeb2Py is capable of working with different protocols, has a built-in error tracker, and has a backward compatibility feature that helps to work on the basis of previous versions of the framework. This means that code maintenance becomes much easier and cheaper. It's free, open-source, and very flexible.

ConsAmong the many Python tools, there are not many that require the latest version of the language. Web2Py is one of those and won't work on Python 3 and below. Therefore, you need to constantly monitor the updates.Web2Py does an excellent job of its tasks. It is quite simple and accessible to everyone.

BlueBream
Python Tools to Try in 2021
BlueBream used to be called Zope3 before. It copes well with tasks of the medium and high level of complexity and is suitable for working on serious projects.

ProsThe BlueBream build system is quite powerful and suitable for complex tasks. You can create functional applications on it, and the principle of reuse of components makes the code easier. At the same time, the speed of development increases. The software can be scaled, and a transactional object database provides an easy path to store it. This means that queries are processed quickly and database management is simple.

ConsThis is not a very flexible framework, it is better to know clearly in advance what is required of it. In addition, it cannot withstand heavy loads. When working with 1000 users at the same time, it can crash and give errors. Therefore, it should be used to solve narrow problems.Python frameworks are often designed for specific tasks. BlueBream is one of these and is suitable for applications where database management plays a key role.

ConclusionPython tools come in different forms and have vastly different capabilities. There are quite a few of them, but in 2021 these will be the most popular and in demand. Experienced programmers always choose several development tools for their comfortable work.

14 June 2021

Enrico Zini: Pipelining

This is part of a series of posts on ideas for an ansible-like provisioning system, implemented in Transilience. Running actions on a server is nice, but a network round trip for each action is not very efficient. If I need to run a linear sequence of actions, I can stream them all to the server, and then read replies streamed from the server as they get executed. This technique is called pipelining and one can see it used, for example, in Redis, or Mitogen. Roles Ansible has the concept of "Roles" as a series of related tasks: I'll play with that. Here's an example role to install and setup fail2ban:
class Role(role.Role):
    def main(self):
        self.add(builtin.apt(
            name=["fail2ban"],
            state="present",
        ))
        self.add(builtin.copy(
            content=inline("""
                [postfix]
                enabled = true
                [dovecot]
                enabled = true
            """),
            dest="/etc/fail2ban/jail.local",
            owner="root",
            group="root",
            mode=0o644,
        ), name="configure fail2ban")
I prototyped roles as classes, with methods that push actions down the pipeline. If an action fails, all further actions for the same role won't executed, and will be marked as skipped. Since skipping is applied per-role, it means that I can blissfully stream actions for multiple roles to the server down the same pipe, and errors in one role will stop executing that role and not others. Potentially I can get multiple roles going with a single network round-trip:
#!/usr/bin/python3
import sys
from transilience.system import Mitogen
from transilience.runner import Runner
@Runner.cli
def main():
    system = Mitogen("my server", "ssh", hostname="server.example.org", username="root")
    runner = Runner(system)
    # Send roles to the server
    runner.add_role("general")
    runner.add_role("fail2ban")
    runner.add_role("prosody")
    # Run until all roles are done
    runner.main()
if __name__ == "__main__":
    sys.exit(main())
That looks like a playbook, using Python as glue rather than YAML. Decision making in roles Besides filing a series of actions, a role may need to take decisions based on the results of previous actions, or on facts discovered from the server. In that case, we need to wait until the results we need come back from the server, and then decide if we're done or if we want to send more actions down the pipe. Here's an example role that installs and configures Prosody:
from transilience import actions, role
from transilience.actions import builtin
from .handlers import RestartProsody
class Role(role.Role):
    """
    Set up prosody XMPP server
    """
    def main(self):
        self.add(actions.facts.Platform(), then=self.have_facts)
        self.add(builtin.apt(
            name=["certbot", "python-certbot-apache"],
            state="present",
        ), name="install support packages")
        self.add(builtin.apt(
            name=["prosody", "prosody-modules", "lua-sec", "lua-event", "lua-dbi-sqlite3"],
            state="present",
        ), name="install prosody packages")
    def have_facts(self, facts):
        facts = facts.facts  # Malkovich Malkovich Malkovich!
        domain = facts["domain"]
        ctx =  
            "ansible_domain": domain
         
        self.add(builtin.command(
            argv=["certbot", "certonly", "-d", f"chat. domain ", "-n", "--apache"],
            creates=f"/etc/letsencrypt/live/chat. domain /fullchain.pem"
        ), name="obtain chat certificate")
        with self.notify(RestartProsody):
            self.add(builtin.copy(
                content=self.template_engine.render_file("roles/prosody/templates/prosody.cfg.lua", ctx),
                dest="/etc/prosody/prosody.cfg.lua",
            ), name="write prosody configuration")
            self.add(builtin.copy(
                src="roles/prosody/templates/firewall-ruleset.pfw",
                dest="/etc/prosody/firewall-ruleset.pfw",
            ), name="write prosody firewall")
    # ...
This files some general actions down the pipe, with a hook that says: when the results of this action come back, run self.have_facts(). At that point, the role can use the results to build certbot command lines, render prosody's configuration from Jinja2 templates, and use the results to file further action down the pipe. Note that this way, while the server is potentially still busy installing prosody, we're already streaming prosody's configuration to it. If anything goes wrong with the installation of prosody's package, the role will be marked as failed and all further actions of the same role, even those filed by have_facts() will be skipped. Notify and handlers In the previous example self.notify() also appears: that's my attempt to model the equivalent of Ansible's handlers. If any of the actions inside the with produce changes, then the RestartProsody role will be executed, potentially filing more actions ad the end of the playbook. The runner will take care of collecting all the triggered role classes in a set, which discards duplicates, and then running the main() method of all resulting roles, which will cause more actions to be filed down the pipe. Action conditions Sometimes some actions are only meaningful as consequences of other actions. Let's take, for example, enabling buster-backports as an extra apt source:
        a = self.add(builtin.copy(
            owner="root",
            group="root",
            mode=0o644,
            dest="/etc/apt/sources.list.d/debian-buster-backports.list",
            content="deb [arch=amd64] https://mirrors.gandi.net/debian/ buster-backports main contrib",
        ), name="enable backports")
        self.add(builtin.apt(
            update_cache=True
        ), name="update after enabling backports",
           # Run only if the previous copy changed anything
           when= a: ResultState.CHANGED ,
        )
Here we want to update Apt's cache, which is a slow operation, only after we actually write /etc/apt/sources.list.d/debian-buster-backports.list. If the file was already there from a previous run, we can skip downloading the new package lists. The when= attributes adds an annotation to the action that is sent town the pipeline, that says that it should only be run if the state of a previous action matches the given one. In this case, when on the remote it's the turn of "update after enabling backports", it gets skipped unless the state of the previous "enable backports" action is CHANGED. Effects of pipelining I ported enough of Ansible's modules to be able to run the provisioning scripts of my VPS entirely via ansible. This is the playbook run as plain Ansible:
$ time ansible-playbook vps.yaml
[...]
servername       : ok=55   changed=1    unreachable=0    failed=0    skipped=0    rescued=0    ignored=0
real    2m10.072s
user    0m33.149s
sys 0m10.379s
This is the same playbook run with Ansible speeded up via the Mitogen backend, which makes Ansible more bearable:
$ export ANSIBLE_STRATEGY=mitogen_linear
$ time ansible-playbook vps.yaml
[...]
servername       : ok=55   changed=1    unreachable=0    failed=0    skipped=0    rescued=0    ignored=0
real    0m24.428s
user    0m8.479s
sys 0m1.894s
This is the same playbook ported to Transilience:
$ time ./provision
[...]
real    0m2.585s
user    0m0.659s
sys 0m0.034s
Doing nothing went from 2 minutes down to 3 seconds! That's the kind of running time that finally makes me comfortable with maintaining my VPS by editing the playbook only, and never logging in to mess with the system configuration by hand! Next steps I'm quite happy with what I have: I can now maintain my VPS with a simple script with quick iterative cycles. I might use it to develop new playbooks, and port them to ansible only when they're tested and need to be shared with infrastructure that needs to rely on something more solid and battle tested than a prototype provisioning system. I might also keep working on it as I have more interesting ideas that I'd like to try. I feel like Ansible reached some architectural limits that are hard to overcome without a major redesign, and are in many way hardcoded in its playbook configuration. It's nice to be able to try out new designs without that baggage. I'd love it if even just the library of Transilience actions could grow, and gain widespread use. Ansible modules standardized a set of management operations, that I think became the way people think about system management, and should really be broadly available outside of Ansible. If you are interesting in playing with Transilience, such as: do get in touch or send a pull request! :) Next step: Reimagining Ansible variables.

12 June 2021

Norbert Preining: Future of Cinnamon in Debian

OK, this is not an easy post. I have been maintaining Cinnamon in Debian for quite some time, since around the times version 4 came out. The soon (hahaha) to be released Bullseye will carry the last release of the 4-track, but version 5 is already waiting, After Bullseye, the future of Cinnamon in Debian currently looks bleak. Since my switch to KDE/Plasma, I haven t used Cinnamon in months. Only occasionally I tested new releases, but never gave them a real-world test. Having left Gnome3 for it s complete lack of usability for pro-users, I escaped to Cinnamon and found a good home there for quite some time using modern technology but keeping user interface changes conservative. For long time I haven t even contemplated using KDE, having been burned during the bad days of KDE3/4 when bloat-as-bloat-can-be was the best description. What revelation it was that KDE/Plasma was more lightweight, faster, responsive, integrated, customizable, all in all simple great. Since my switch to KDE/Plasma I think not for a second I have missed anything from the Gnome3 or Cinnamon world. And that means, I will most probably NOT packaging Cinnamon 5, nor do any real packaging work of Cinnamon for Debian in the future. Of course, I will try to keep maintenance of the current set of packages for Bullseye, but for the next release, I think it is time that someone new steps in. Cinnamon packaging taught me a lot on how to deal with multiple related packages, which is of great use in the KDE packaging world. If someone steps forward, I will surely be around for support and help, but as long as nobody takes the banner, it will mean the end of Cinnamon in Debian. Please contact me if you are interested!

11 June 2021

Colin Watson: SSH quoting

A while back there was a thread on one of our company mailing lists about SSH quoting, and I posted a long answer to it. Since then a few people have asked me questions that caused me to reach for it, so I thought it might be helpful if I were to anonymize the original question and post my answer here. The question was why a sequence of commands involving ssh and fiddly quoting produced the output they did. The first example was this:
$ ssh user@machine.local bash -lc "cd /tmp;pwd"
/home/user
Oh hi, my dubious life choices have been such that this is my specialist subject! This is because SSH command-line parsing is not quite what you expect. First, recall that your local shell will apply its usual parsing, and the actual OS-level execution of ssh will be like this:
[0]: ssh
[1]: user@machine.local
[2]: bash
[3]: -lc
[4]: cd /tmp;pwd
Now, the SSH wire protocol only takes a single string as the command, with the expectation that it should be passed to a shell by the remote end. The OpenSSH client deals with this by taking all its arguments after things like options and the target, which in this case are:
[0]: bash
[1]: -lc
[2]: cd /tmp;pwd
It then joins them with a single space:
bash -lc cd /tmp;pwd
This is passed as a string to the server, which then passes that entire string to a shell for evaluation, so as if you d typed this directly on the server:
sh -c 'bash -lc cd /tmp;pwd'
The shell then parses this as two commands:
bash -lc cd /tmp
pwd
The directory change thus happens in a subshell (actually it doesn t quite even do that, because bash -lc cd /tmp in fact ends up just calling cd because of the way bash -c parses multiple arguments), and then that subshell exits, then pwd is called in the outer shell which still has the original working directory. The second example was this:
$ ssh user@machine.local bash -lc "pwd;cd /tmp;pwd"
/home/user
/tmp
Following the logic above, this ends up as if you d run this on the server:
sh -c 'bash -lc pwd; cd /tmp; pwd'
The third example was this:
$ ssh user@machine.local bash -lc "cd /tmp;cd /tmp;pwd"
/tmp
And this is as if you d run:
sh -c 'bash -lc cd /tmp; cd /tmp; pwd'
Now, I wouldn t have implemented the SSH client this way, because I agree that it s confusing. But /usr/bin/ssh is used as a transport for other things so much that changing its behaviour now would be enormously disruptive, so it s probably impossible to fix. (I have occasionally agitated on openssh-unix-dev@ for at least documenting this better, but haven t made much headway yet; I need to get round to preparing a documentation patch.) Once you know about it you can use the proper quoting, though. In this case that would simply be:
ssh user@machine.local 'cd /tmp;pwd'
Or if you do need to specifically invoke bash -l there for some reason (I m assuming that the original example was reduced from something more complicated), then you can minimise your confusion by passing the whole thing as a single string in the form you want the remote sh -c to see, in a way that ensures that the quotes are preserved and sent to the server rather than being removed by your local shell:
ssh user@machine.local 'bash -lc "cd /tmp;pwd"'
Shell parsing is hard.

10 June 2021

Petter Reinholdtsen: Nikita version 0.6 released - free software archive API server

I am very pleased to be able to share with you the announcement of a new version of the archiving system Nikita published by its lead developer Thomas S dring:
It is with great pleasure that we can announce a new release of nikita. Version 0.6 (https://gitlab.com/OsloMet-ABI/nikita-noark5-core). This release makes new record keeping functionality available. This really is a maturity release. Both in terms of functionality but also code. Considerable effort has gone into refactoring the codebase and simplifying the code. Notable changes for this release include:
  • Significantly improved OData parsing
  • Support for business specific metadata and national identifiers
  • Continued implementation of domain model and endpoints
  • Improved testing
  • Ability to export and import from arkivstruktur.xml
We are currently in the process of reaching an agreement with an archive institution to publish their picture archive using nikita with business specific metadata and we hope that we can share this with you soon. This is an interesting project as it allows the organisation to bring an older picture archive back to life while using the original metadata values stored as business specific metadata. Combined with OData means the scope and use of the archive is significantly increased and will showcase both the flexibility and power of Noark. I really think we are approaching a version 1.0 of nikita, even though there is still a lot of work to be done. The notable work at the moment is to implement access-control and full text indexing of documents. My sincere thanks to everyone who has contributed to this release! - Thomas Release 0.6 2021-06-10 (d1ba5fc7e8bad0cfdce45ac20354b19d10ebbc7b)
  • Refactor metadata entity search
  • Remove redundant security configuration
  • Make OpenAPI documentation work
  • Change database structure / inheritance model to a more sensible approach
  • Make it possible to move entities around the fonds structure
  • Implemented a number of missing endpoints
  • Make sure yml files are in sync
  • Implemented/finalised storing and use of
    • Business Specific Metadata
    • Norwegian National Identifiers
    • Cross Reference
    • Keyword
    • StorageLocation
    • Author
    • Screening for relevant objects
    • ChangeLog
    • EventLog
  • Make generation of updated docker image part of successful CI pipeline
  • Implement pagination for all list requests
    • Refactor code to support lists
    • Refactor code for readability
    • Standardise the controller/service code
  • Finalise File->CaseFile expansion and Record->registryEntry/recordNote expansion
  • Improved Continuous Integration (CI) approach via gitlab
  • Changed conversion approach to generate tagged PDF documents
  • Updated dependencies
    • For security reasons
    • Brought codebase to spring-boot version 2.5.0
    • Remove import of necessary dependencies
    • Remove non-used metrics classes
  • Added new analysis to CI including
  • Implemented storing of Keyword
  • Implemented storing of Screening and ScreeningMetadata
  • Improved OData support
    • Better support for inheritance in queries where applicable
    • Brought in more OData tests
    • Improved OData/hibernate understanding of queries
    • Implement $count, $orderby
    • Finalise $top and $skip
    • Make sure & is used between query parameters
  • Improved Testing in codebase
    • A new approach for integration tests to make test more readable
    • Introduce tests in parallel with code development for TDD approach
    • Remove test that required particular access to storage
  • Implement case-handling process from received email to case-handler
    • Develop required GUI elements (digital postroom from email)
    • Introduced leader, quality control and postroom roles
  • Make PUT requests return 200 OK not 201 CREATED
  • Make DELETE requests return 204 NO CONTENT not 200 OK
  • Replaced 'oppdatert*' with 'endret*' everywhere to match latest spec
  • Upgrade Gitlab CI to use python > 3 for CI scripts
  • Bug fixes
    • Fix missing ALLOW
    • Fix reading of objects from jar file during start-up
    • Reduce the number of warnings in the codebase
    • Fix delete problems
    • Make better use of cascade for "leaf" objects
    • Add missing annotations where relevant
    • Remove the use of ETAG for delete
    • Fix missing/wrong/broken rels discovered by runtest
    • Drop unofficial convertFil (konverterFil) end point
    • Fix regex problem for dateTime
    • Fix multiple static analysis issues discovered by coverity
    • Fix proxy problem when looking for object class names
    • Add many missing translated Norwegian to English (internal) attribute/entity names
    • Change UUID generation approach to allow code also set a value
    • Fix problem with Part/PartParson
    • Fix problem with empty OData search results
    • Fix metadata entity domain problem
  • General Improvements
    • Makes future refactoring easier as coupling is reduced
    • Allow some constant variables to be set from property file
    • Refactor code to make reflection work better across codebase
    • Reduce the number of @Service layer classes used in @Controller classes
    • Be more consistent on naming of similar variable types
    • Start printing rels/href if they are applicable
    • Cleaner / standardised approach to deleting objects
    • Avoid concatenation when using StringBuilder
    • Consolidate code to avoid duplication
    • Tidy formatting for a more consistent reading style across similar class files
    • Make throw a log.error message not an log.info message
    • Make throw print the log value rather than printing in multiple places
    • Add some missing pronom codes
    • Fix time formatting issue in Gitlab CI
    • Remove stale / unused code
    • Use only UUID datatype rather than combination String/UUID for systemID
    • Mark variables final and @NotNull where relevant to indicate intention
  • Change Date values to DateTime to maintain compliance with Noark 5 standard
  • Domain model improvements using Hypersistence Optimizer
    • Move @Transactional from class to methods to avoid borrowing the JDBC Connection unnecessarily
    • Fix OneToOne performance issues
    • Fix ManyToMany performance issues
    • Add missing bidirectional synchronization support
    • Fix ManyToMany performance issue
  • Make List
  • and Set
  • use final-keyword to avoid potential problems during update operations
  • Changed internal URLs, replaced "hateoas-api" with "api".
  • Implemented storing of Precedence.
  • Corrected handling of screening.
  • Corrected _links collection returned for list of mixed entity types to match the specific entity.
  • Improved several internal structures.
If free and open standardized archiving API sound interesting to you, please contact us on IRC (#nikita on irc.oftc.net) or email (nikita-noark mailing list). As usual, if you use Bitcoin and want to show your support of my activities, please send Bitcoin donations to my address 15oWEoG9dUPovwmUL9KWAnYRtNJEkP1u1b.

Louis-Philippe V ronneau: New Desktop Computer

I built my last desktop computer what seems like ages ago. In 2011, I was in a very different place, both financially and as a person. At the time, I was earning minimum wage at my school's caf to pay rent. Since the caf was owned by the school cooperative, I had an employee discount on computer parts. This gave me a chance to build my first computer from spare parts at a reasonable price. After 10 years of service1, the time has come to upgrade. Although this machine was still more than capable for day to day tasks like browsing the web or playing casual video games, it started to show its limits when time came to do more serious work. Old computer specs:
CPU: AMD FX-8530
Memory: 8GB DDR3 1600Mhz
Motherboard: ASUS TUF SABERTOOTH 990FX R2.0
Storage: Samsung 850 EVO 500GB SATA
I first started considering an upgrade in September 2020: David Bremner was kindly fixing a bug in ledger that kept me from balancing my books and since it seemed like a class of bug that would've been easily caught by an autopkgtest, I decided to add one. After adding the necessary snippets to run the upstream testsuite (an easy task I've done multiple times now), I ran sbuild and ... my computer froze and crashed. Somehow, what I thought was a simple Python package was maxing all the cores on my CPU and using all of the 8GB of memory I had available.2 A few month later, I worked on jruby and the builds took 20 to 30 minutes long enough to completely disrupt my flow. The same thing happened when I wanted to work on lintian: the testsuite would take more than 15 minutes to run, making quick iterations impossible. Sadly, the pandemic completely wrecked the computer hardware market and prices here in Canada have only recently started to go down again. As a result, I had to wait more time than I would've liked not to pay scalper prices. New computer specs:
CPU: AMD Ryzen 5900X
Memory: 64GB DDR4 3200MHz
Motherboard: MSI MPG B550 Gaming Plus
Storage: Corsair MP600 500 GB Gen4 NVME
The difference between the two machines is pretty staggering: I've gone from a CPU with 2 cores and 8 threads, to one with 12 cores and 24 threads. Not only that, but single-threaded performance has also vastly increased in those 10 years. A good example would be building grammalecte, a package I've recently sponsored. I feel it's a good benchmark, since the build relies on single-threaded performance for the normal Python operations, while being threaded when it compiles the dictionaries. On the old computer:
Build needed 00:10:07, 273040k disk space
And as you can see, on the new computer the build time has been significantly reduced:
Build needed 00:03:18, 273040k disk space
Same goes for things like the lintian testsuite. Since it's a very multi-threaded workload, it now takes less than 2 minutes to run; a 750% improvement. All this to say I'm happy with my purchase. And lo and behold I can now build ledger without a hitch, even though it maxes my 24 threads and uses 28GB of RAM. Who would've thought... Screen capture of htop showing how much resources ledger takes to build

  1. I managed to fry that PC's motherboard in 2016 and later replaced it with a brand new one. I also upgraded the storage along the way, from a very cheap cacheless 120GB SSD to a larger Samsung 850 EVO SATA drive.
  2. As it turns out, ledger is mostly written in C++ :)

7 June 2021

Russell Coker: Dell PowerEdge T320 and Linux

I recently bought a couple of PowerEdge T320 servers, so now to learn about setting them up. They are a little newer than the R710 I recently setup (which had iDRAC version 6), they have iDRAC version 7. RAM Speed One system has a E5-2440 CPU with 2*16G DDR3 DIMMs and a Memtest86+ speed of 13,043MB/s, the other is essentially identical but with a E5-2430 CPU and 4*16G DDR3 DIMMs and a Memtest86+ speed of 8,270MB/s. I had expected that more DIMMs means better RAM performance but this isn t what happened. I firstly upgraded the BIOS, as I expected it didn t make a difference but it s a good thing to try first. On the E5-2430 I tried removing a DIMM after it was pointed out on Facebook that the CPU has 3 memory channels (here s a link to a great site with information on that CPU and many others [1]). When I did that I was prompted to disable advanced ECC (which treats pairs of DIMMs as a single unit for ECC allowing correcting more than 1 bit errors) and I had to move the 3 remaining DIMMS to different slots. That improved the performance to 13,497MB/s. I then put the spare DIMM into the E5-2440 system and the performance increased to 13,793MB/s, when I installed 4 DIMMs in the E5-2440 system the performance remained at 13,793MB/s and the E5-2430 went down to 12,643MB/s. This is a good result for me, I now have the most RAM and fastest RAM configuration in the system with the fastest CPU. I ll sell the other one to someone who doesn t need so much RAM or performance (it will be really good for a small office mail server and NAS). Firmware Update BIOS The first issue is updating the BIOS, unfortunately the first link I found to the Dell web site didn t have a link to download the Linux installer. It offered a Windows binary, an EFI program, and a DOS binary. I m not about to install Windows if there is any other option and EFI is somewhat annoying, so that leaves DOS. The first Google result for installing FreeDOS advised using unetbootin , that didn t work at all for me (created a USB image that the Dell BIOS didn t recognise as bootable) and even if it did it wouldn t have been a good solution. I went to the FreeDOS download page [2] and got the Lite USB zip file. That contained FD12LITE.img which I could just dd to a USB stick. I then used fdisk to create a second 32MB partition, used mkfs.fat to format it, and then copied the BIOS image file to it. I booted the USB stick and then ran the BIOS update program from drive D:. After the BIOS update this became the first system I ve seen get a totally green result from spectre-meltdown-checker ! I found the link to the Linux installer for the new Dell BIOS afterwards, but it was still good to play with FreeDOS. PERC Driver I probably didn t really need to update the PERC (PowerEdge Raid Controller) firmware as I m just going to run it in JBOD mode. But it was easy to do, a simple bash shell script to update it. Here are the perccli commands needed to access disks, it s all hot-plug so you can insert disks and do all this without a reboot:
# show overview
perccli show
# show controller 0 details
perccli /c0 show all
# show controller 0 info with less detail
perccli /c0 show
# clear all "foreign" RAID members
perccli /c0 /fall delete
# add a vd (RAID) of level RAID0 (r0) with the drive 32:0 (enclosure:slot from above command)
perccli /c0 add vd r0 drives=32:0
The perccli /c0 show command gives the following summary of disk ( PD in perccli terminology) information amongst other information. The EID is the enclosure, Slt is the slot (IE the bay you plug the disk into) and the DID is the disk identifier (not sure what happens if you have multiple enclosures). The allocation of device names (sda, sdb, etc) will be in order of EID:Slt or DID at boot time, and any drives added at run time will get the next letters available.
----------------------------------------------------------------------------------
EID:Slt DID State DG       Size Intf Med SED PI SeSz Model                     Sp 
----------------------------------------------------------------------------------
32:0      0 Onln   0  465.25 GB SATA SSD Y   N  512B Samsung SSD 850 EVO 500GB U  
32:1      1 Onln   1  465.25 GB SATA SSD Y   N  512B Samsung SSD 850 EVO 500GB U  
32:3      3 Onln   2   3.637 TB SATA HDD N   N  512B ST4000DM000-1F2168        U  
32:4      4 Onln   3   3.637 TB SATA HDD N   N  512B WDC WD40EURX-64WRWY0      U  
32:5      5 Onln   5 278.875 GB SAS  HDD Y   N  512B ST300MM0026               U  
32:6      6 Onln   6 558.375 GB SAS  HDD N   N  512B AL13SXL600N               U  
32:7      7 Onln   4   3.637 TB SATA HDD N   N  512B ST4000DM000-1F2168        U  
----------------------------------------------------------------------------------
The PERC controller is a MegaRAID with possibly some minor changes, there are reports of Linux MegaRAID management utilities working on it for similar functionality to perccli. The version of MegaRAID utilities I tried didn t work on my PERC hardware. The smartctl utility works on those disks if you tell it you have a MegaRAID controller (so obviously there s enough similarity that some MegaRAID utilities will work). Here are example smartctl commands for the first and last disks on my system. Note that the disk device node doesn t matter as all device nodes associated with the PERC/MegaRAID are equal for smartctl.
# get model number etc on DID 0 (Samsung SSD)
smartctl -d megaraid,0 -i /dev/sda
# get all the basic information on DID 0
smartctl -d megaraid,0 -a /dev/sda
# get model number etc on DID 7 (Seagate 4TB disk)
smartctl -d megaraid,7 -i /dev/sda
# exactly the same output as the previous command
smartctl -d megaraid,7 -i /dev/sdc
I have uploaded etbemon version 1.3.5-6 to Debian which has support for monitoring smartctl status of MegaRAID devices and NVMe devices. IDRAC To update IDRAC on Linux there s a bash script with the firmware in the same file (binary stuff at the end of a shell script). To make things a little more exciting the script insists that rpm be available (running apt install rpm fixes that for a Debian system). It also creates and runs other shell scripts which start with #!/bin/sh but depend on bash syntax. So I had to make /bin/sh a symlink to /bin/bash. You know you need this if you see errors like typeset: not found and [: -eq: unexpected operator and then the system reboots. Dell people, please test your scripts on dash (the Debian /bin/sh) or just specify #!/bin/bash. If the IDRAC update works it will take about 8 minutes. Lifecycle Controller The Lifecycle Controller is apparently for installing OS and firmware updates. I use Linux tools to update Linux and I generally don t plan to update the firmware after deployment (although I could do so from Linux if needed). So it doesn t seem to offer anything useful to me. Setting Up IDRAC For extra excitement I decided to try to setup IDRAC from the Linux command-line. To install the RAC setup tool you run apt install srvadmin-idracadm7 libargtable2-0 (because srvadmin-idracadm7 doesn t have the right dependencies).
# srvadmin-idracadm7 is missing a dependency
apt install srvadmin-idracadm7 libargtable2-0
# set the IP address, netmask, and gatewat for IDRAC
idracadm7 setniccfg -s 192.168.0.2 255.255.255.0 192.168.0.1
# put my name on the front panel LCD
idracadm7 set System.LCD.UserDefinedString "Russell Coker"
Conclusion This is a very nice deskside workstation/server. It s extremely quiet with hardly any fan noise and the case is strong enough to contain the noise of hard drives. When running with 3* 3.5 SATA disks and 2*10k 2.5 SAS disks on a wooden floor it wasn t annoyingly loud. Without the SAS disks it was as quiet as you can expect any PC to be, definitely not the volume you expect from a serious server! I bought the T320 systems loaded with SAS disks which made them quite loud, I immediately put the disks on ebay and installed SATA SSDs and hard drives which gives me more performance and more space than the SAS disks with less cost and almost no noise. 8*3.5 drive bays gives room for expansion. I currently have 2*SATA SSDs and 3*SATA disks, the SSDs are for the root filesystem (including /home) and the disks are for a separate filesystem for large files.

Russ Allbery: Review: Stoneskin

Review: Stoneskin, by K.B. Spangler
Series: Deep Witches #0
Publisher: A Girl and Her Fed Books
Copyright: September 2017
ASIN: B075PHK498
Format: Kindle
Pages: 226
Stoneskin is a prequel to the Deep Witches Trilogy, which is why I have it marked as book 0 of the series. Unlike most prequels, it was written and published before the series and there doesn't seem to be any reason not to read it first. Tembi Moon is an eight-year-old girl from the poor Marumaru area on the planet of Adhama. Humanity has spread to the stars and first terraformed the worlds and then bioformed themselves to live there. The differences are subtle, but Tembi's skin becomes thicker and less sensitive when damaged (either physically or emotionally) and she can close her ears against dust storms. One day, she wakes up in an unknown alley and finds herself on the world of Miha'ana, sixteen thousand light-years away, where she is rescued and brought home by a Witch named Matindi. In this science fiction future, nearly all interstellar travel is done through the Deep. The Deep is not like the typical hand-waved science fiction subspace, most notably in that it's alive. No one is entirely sure where it came from or what sort of creature it is. It sometimes manages to communicate in words, but abstract patterns with feelings attached are more common, and it only communicates with specific people. Those people are Witches, who are chosen by the Deep via some criteria no one understands. Witches can use the Deep to move themselves or anything else around the galaxy. All interstellar logistics rely on them. The basics of Tembi's story are not that unusual; she's been chosen by the Deep to be a Witch. What is remarkable is that she's young and she's poor, completely disconnected from the power structures of the galaxy. But, once chosen, her path as far as the rest of the galaxy is concerned is fixed: she will go to Lancaster to be trained as a Witch. Matindi is able to postpone this for a time by keeping an eye on her, but not forever. I bought this book because of the idea of the Deep, and that is indeed the best part of the book. There is a lot of mystery about its exact nature, most of which is not resolved in this book, but it mostly behaves like a giant and extremely strange dog, and it's awesome. Replacing the various pseudo-scientific explanations for faster than light travel with interactions with a dream-weird giant St. Bernard with too many paws that talks in swirls of colored bubbles and is very eager to please its friends is brilliant. This book covers a lot of years of Tembi's life and is, as advertised, a prelude to a story that is not resolved here. It's a coming of age story in which she does eventually end up at Lancaster, learns and chafes at the elaborate and very conservative structures humans have put in place to try to make interactions with the Deep predictable and reliable, and eventually gets drawn into the politics of war and the question of when people have a responsibility to intervene. Tembi, and the reader, also have many opportunities to get extremely upset at how the Deep is treated and how much entitlement the Witches have about their access and control, although how the Deep feels about it is left for a future book. Not all of this story is as good as the premise. There are some standard coming of age tropes that I'm not fond of, such as Tembi's predictable temporary falling out with the Deep (although the Deep's reaction is entertaining). It's also not at all a complete story, although that's clearly signaled by the subtitle. But as an introduction to the story universe and an extended bit of scene-setting, it accomplishes what it sets out to do. It's also satisfyingly thoughtful about the moral trade-offs around stability and the value of preserving institutions. I know which side I'm on within the universe, but I appreciated how much nuance and thoughtfulness Spangler puts into the contrary opinion. I'm hooked on the universe and want to learn more about the Deep, enough so that I've already bought the first book of the main trilogy. Followed by The Blackwing War. Rating: 7 out of 10

6 June 2021

Iustin Pop: Goodbye Travis, hello GitHub Actions

My very cyclical open-source work For some reason, I only manage to do coding at home every some months - mostly 6 months apart, so twice a year (even worse than my blogging frequency :P). As such, I missed the whole discussion about travis-ci (the .org version) going away, etc. So when I finally did some work on corydalis a few weeks ago, and had a travis build failure (restoring a large cache simply timed out, either travis or S3 has some hiccup - it cleared by itself a day later), I opened the travis-ci interface to see the scary banner ( travis-ci.org is shutting down ), and asked myself what s happening. The deadline was in less than a week even Long story short, Travis was a good home for many years, but they were bought and are doing significant changes to their OSS support, so it s time to move on. I anyway wanted to learn GitHub Actions for a while (ahem, free time intervened), so this was a good (forced) opportunity .

Proper composable CI The advantage of Travis infrastructure was that the build configuration was really simple. It had very few primitives: pre-steps (before_install), install steps, and the actual things to do to test, post-steps (after_sucess) and a few other small helpers (caching, apt packages, etc.) This made it really easy to just pick up and write a config, plus it had the advantage of allowing to test configs from the web UI without needing to push. This simplicity was unfortunately also its significant limiter: the way to do complex things in steps was simply to add more shell commands. GitHub actions, together with its marketplace, changes this entirely. There are no built-in actions, the language just defines the build/job/step hierarchy, and one glues together whatever steps they want. This has the disadvantage that even checking out the code needs to be explicitly written in all workflows (so boilerplate, if you don t need customisation), but it opens up a huge opportunity for composition, since it allows people to publish actions (steps) that you just import, encapsulating all the work. So, after learning how to write a moderately complicated workflow (complicated as in multiple Python version, some of them needing different OS version, and multi-OS), it was straightforward to port this to all my projects - just somewhat tedious. I ve now shutdown all builds on Travis, just can t find a way to delete my account

Better multi-OS, worse (missing) multi-arch In theory, Travis supports Linux, MacOS, FreeBSD and Windows, but I ve found that support for non-Linux is not quite as good. Maybe I missed things, but multi-version Python builds on MacOS were not as nicely supported as Linux; Windows is quite early, and very limited; and I haven t tested FreeBSD. GitHub is more restrictive - Linux, MacOS and Windows - but I found support for MacOS and Windows better for my use cases. If your use case is testing multiple MacOS versions, Travis wins, if it s more varied languages/etc. on the single available MacOS version, GitHub works better. On the multi-arch side, Travis wins hands-down. Four different native architectures, and enabling one more is just adding another key to the arch list. With GitHub, if I understand right, you either have to use docker+emulation, or use self-hosted runners. So here it really matters what is more important to you. Maybe in the future GitHub will support more arches, but right now, Travis wins for this use-case.

Summary For my specific use-case, GitHub Actions is a better fit right now. The marketplace has advantages (I ll explain better in a future post), the actions are a very nice way to encapsulate functionality, and it s still available/free (up to a limit) for open source projects. I don t know what the future of Travis for OSS will be, but all I heard so far is very concerning. However, I ll still miss a few things. For example, an overall dashboard for all my projects, like this one:
Travis dashboard Travis dashboard
I couldn t find any such thing on GitHub, so I just use my set of badges. Then cache management. Travis allows you to clear the cache, and it does auto-update the cache. GitHub caches are immutable once built, so you have to:
  • watch if changed dependencies/dependency chains result in things that are no longer cached;
  • if so, need to manually bump the cache key, resulting in a commit for purely administrative purposes.
For languages where you have a clean full chain of dependencies recorded (e.g. node s package-lock.json, stack s stack.yaml.lock), this is trivial to achieve, but gets complicated if you add OS dependencies, languages which don t record all this, etc. Hmm, maybe I should just embed the year/month in the cache name - cheating, but automated cheating. With all said and done, I think GHA is much less refined, but with more potential. Plus, the pace of innovation on Travis side was quite slow (likely money problems, hence them being bought, etc.) So one TODO done: learn GitHub Actions , even if a bit unplanned

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