Search Results: "tar"

20 September 2021

Jamie McClelland: Putty Problems

I upgraded my first servers from buster to bullseye over the weekend and it went very smoothly, so big thank you to all the debian developers who contributed your labor to the bullseye release! This morning, however, I hit a snag when the first windows users tried to login. It seems like a putty bug (see update below). First, the user received an error related to algorithm selection. I didn t record the exact error and simply suggested that the user upgrade. Once the user was running the latest version of putty (0.76), they received a new error: 
Server refused public-key signature despite accepting key!
I turned up debugging on the server and recorded: 
Sep 20 13:10:32 container001 sshd[1647842]: Accepted key RSA SHA256:t3DVS5wZmO7DVwqFc41AvwgS5gx1jDWnR89apGmFpf4 found at /home/XXXXXXXXX/.ssh/authorized_keys:6
Sep 20 13:10:32 container001 sshd[1647842]: debug1: restore_uid: 0/0
Sep 20 13:10:32 container001 sshd[1647842]: Postponed publickey for XXXXXXXXX from xxx.xxx.xxx.xxx port 63579 ssh2 [preauth]
Sep 20 13:10:33 container001 sshd[1647842]: debug1: userauth-request for user XXXXXXXXX service ssh-connection method publickey [preauth]
Sep 20 13:10:33 container001 sshd[1647842]: debug1: attempt 2 failures 0 [preauth]
Sep 20 13:10:33 container001 sshd[1647842]: debug1: temporarily_use_uid: 1000/1000 (e=0/0)
Sep 20 13:10:33 container001 sshd[1647842]: debug1: trying public key file /home/XXXXXXXXX/.ssh/authorized_keys
Sep 20 13:10:33 container001 sshd[1647842]: debug1: fd 5 clearing O_NONBLOCK
Sep 20 13:10:33 container001 sshd[1647842]: debug1: /home/XXXXXXXXX/.ssh/authorized_keys:6: matching key found: RSA SHA256:t3DVS5wZmO7DVwqFc41AvwgS5gx1jDWnR89apGmFpf4
Sep 20 13:10:33 container001 sshd[1647842]: debug1: /home/XXXXXXXXX/.ssh/authorized_keys:6: key options: agent-forwarding port-forwarding pty user-rc x11-forwarding
Sep 20 13:10:33 container001 sshd[1647842]: Accepted key RSA SHA256:t3DVS5wZmO7DVwqFc41AvwgS5gx1jDWnR89apGmFpf4 found at /home/XXXXXXXXX/.ssh/authorized_keys:6
Sep 20 13:10:33 container001 sshd[1647842]: debug1: restore_uid: 0/0
Sep 20 13:10:33 container001 sshd[1647842]: debug1: auth_activate_options: setting new authentication options
Sep 20 13:10:33 container001 sshd[1647842]: Failed publickey for XXXXXXXXX from xxx.xxx.xxx.xxx port 63579 ssh2: RSA SHA256:t3DVS5wZmO7DVwqFc41AvwgS5gx1jDWnR89apGmFpf4
Sep 20 13:10:39 container001 sshd[1647514]: debug1: Forked child 1648153.
Sep 20 13:10:39 container001 sshd[1648153]: debug1: Set /proc/self/oom_score_adj to 0
Sep 20 13:10:39 container001 sshd[1648153]: debug1: rexec start in 5 out 5 newsock 5 pipe 8 sock 9
Sep 20 13:10:39 container001 sshd[1648153]: debug1: inetd sockets after dupping: 4, 4
The server log seems to agree with the client returned message: first the key was accepted, then it was refused. We re-generated a new key. We turned off the windows firewall. We deleted all the putty settings via the windows registry and re-set them from scratch. Nothing seemed to work. Then, another windows user reported no problem (and that user was running putty version 0.74). So the first user downgraded to 0.74 and everything worked fine.

Update Wow, very impressed with the responsiveness of putty devs! And, who knew that putty is available in debian?? Long story short: putty version 0.76 works on linux and, from what I can tell, works for everyone except my one user. Maybe it s their provider doing some filtering? Maybe a nuance to their version of Windows?

Andy Simpkins: COVID-19

Nearly 4 weeks after contracting COVID-19 I am finally able to return to work Yes I have had both Jabs (my 2nd dose was back in June), and this knocked me for six. I spent most of the time in bed, and only started to get up and about 10 days ago. I passed this on to both my wife and daughter (my wife has also been double jabbed), fortunately they didn t get it as bad as me and have been back at work / school for the last week. I also passed it on to a friend at the UK Debian BBQ, hosted once again by Sledge and Randombird, before I started showing symptoms. Fortunately (after a lot of PCR tests for attendees) it doesn t look like I passed it to anyone else I wouldn t wish this on anyone. I went on holiday back in August (still in England) thinking that having both jabs we would be fine. We stayed in self catering accommodation and we spent our time outside, we visited open air museums, walked around gardens etc, however we did eat out in relatively empty pubs and restaurants. And yes we did all have face masks on when we went indoors (although obviously we removed them whilst eating). I guess that is when I caught this, but have no idea exactly when or where. Even after vaccination, it is still possible to both catch and spread this virus. Fortunately having been vaccinated my resulting illness was (statistically) less bad than it would otherwise have been. I dread to think how bad I would have been if I had not already been vaccinated, I suspect that I would have ended up in ICU. I am still very tired, and have been told it may take many more weeks to get back to my former self. Other than being overweight, prior to this I have been in good health. If you are reading this and have NOT yet had a vaccine and one is available for you, please, please get it done.

16 September 2021

Chris Lamb: On Colson Whitehead's Harlem Shuffle

Colson Whitehead's latest novel, Harlem Shuffle, was always going to be widely reviewed, if only because his last two books won Pulitzer prizes. Still, after enjoying both The Underground Railroad and The Nickel Boys, I was certainly going to read his next book, regardless of what the critics were saying indeed, it was actually quite agreeable to float above the manufactured energy of the book's launch. Saying that, I was encouraged to listen to an interview with the author by Ezra Klein. Now I had heard Whitehead speak once before when he accepted the Orwell Prize in 2020, and once again he came across as a pretty down-to-earth guy. Or if I were to emulate the detached and cynical tone Whitehead embodied in The Nickel Boys, after winning so many literary prizes in the past few years, he has clearly rehearsed how to respond to the cliched questions authors must be asked in every interview. With the obligatory throat-clearing of 'so, how did you get into writing?', for instance, Whitehead replies with his part of the catechism that 'It seemed like being a writer could be a cool job. You could work from home and not talk to people.' The response is the right combination of cute and self-effacing... and with its slight tone-deafness towards enforced isolation, it was no doubt honed before Covid-19. Harlem Shuffle tells three separate stories about Ray Carney, a furniture salesman and 'fence' for stolen goods in New York in the 1960s. Carney doesn't consider himself a genuine criminal though, and there's a certain logic to his relativistic morality. After all, everyone in New York City is on the take in some way, and if some 'lightly used items' in Carney's shop happened to have had 'previous owners', well, that's not quite his problem. 'Nothing solid in the city but the bedrock,' as one character dryly observes. Yet as Ezra pounces on in his NYT interview mentioned abov, the focus on the Harlem underworld means there are very few women in the book, and Whitehead's circular response ah well, it's a book about the criminals at that time! was a little unsatisfying. Not only did it feel uncharacteristically slippery of someone justly lauded for his unflinching power of observation (after all, it was the author who decided what to write about in the first place), it foreclosed on the opportunity to delve into why the heist and caper genres (from The Killing, The Feather Thief, Ocean's 11, etc.) have historically been a 'male' mode of storytelling. Perhaps knowing this to be the case, the conversation quickly steered towards Ray Carney's wife, Elizabeth, the only woman in the book who could be said possesses some plausible interiority. The following off-hand remark from Whitehead caught my attention:
My wife is convinced that [Elizabeth] knows everything about Carney's criminal life, and is sort of giving him a pass. And I'm not sure if that's true. I have to have to figure out exactly what she knows and when she knows it and how she feels about it.
I was quite taken by this, although not simply due to its effect on the story it self. As in, it immediately conjured up a charming picture of Whitehead's domestic arrangements: not only does Whitehead's wife feel free to disagree with what one of Whitehead's 'own' characters knows or believes, but that Colson has no problem whatsoever sharing that disagreement with the public at large. (It feels somehow natural that Whitehead's wife believes her counterpart knows more than she lets on, whilst Whitehead himself imbues the protagonist's wife with a kind of neo-Victorian innocence.) I'm minded to agree with Whitehead's partner myself, if only due to the passages where Elizabeth is studiously ignoring Carney's otherwise unexplained freak-outs. But all of these meta-thoughts simply underline just how emancipatory the Death of the Author can be. This product of academic literary criticism (the term was coined by Roland Barthes' 1967 essay of the same name) holds that the original author's intentions, ideas or biographical background carry no especial weight in determining how others should interpret their work. It is usually understood as meaning that a writer's own views are no more valid or 'correct' than the views held by someone else. (As an aside, I've found that most readers who encounter this concept for the first time have been reading books in this way since they were young. But the opposite is invariably true with cinephiles, who often have a bizarre obsession with researching or deciphering the 'true' interpretation of a film.) And with all that in mind, can you think of a more wry example of how freeing (and fun) nature of the Death of the Author than an author's own partner dissenting with their (Pulitzer Prize-winning) husband on the position of a lynchpin character?
The 1964 Harlem riot began after James Powell, a 15-year-old African American, was shot and killed by Thomas Gilligan, an NYPD police officer in front of 10s of witnesses. Gilligan was subsequently cleared by a grand jury.
As it turns out, the reviews for Harlem Shuffle have been almost universally positive, and after reading it in the two days after its release, I would certainly agree it is an above-average book. But it didn't quite take hold of me in the way that The Underground Railroad or The Nickel Boys did, especially the later chapters of The Nickel Boys that were set in contemporary New York and could thus make some (admittedly fairly explicit) connections from the 1960s to the present day that kind of connection is not there in Harlem Shuffle, or at least I did not pick up on it during my reading. I can see why one might take exception to that, though. For instance, it is certainly true that the week-long Harlem Riot forms a significant part of the plot, and some events in particular are entirely contingent on the ramifications of this momentous event. But it's difficult to argue the riot's impact are truly integral to the story, so not only is this uprising against police brutality almost regarded as a background event, any contemporary allusion to the murder of George Floyd is subsequently watered down. It's nowhere near the historical rubbernecking of Forrest Gump (1994), of course, but that's not a battle you should ever be fighting. Indeed, whilst a certain smoothness of affect is to be priced into the Whitehead reading experience, my initial overall reaction to Harlem Shuffle was fairly flat, despite all the action and intrigue on the page. The book perhaps belies its origins as a work conceived during quarantine after all, the book is essentially comprised of three loosely connected novellas, almost as if the unreality and mental turbulence of lockdown prevented the author from performing the psychological 'deep work' of producing a novel-length text with his usual depth of craft. A few other elements chimed with this being a 'lockdown novel' as well, particularly the book's preoccupation with the sheer physicality of the city compared to the usual complex interplay between its architecture and its inhabitants. This felt like it had been directly absorbed into the book from the author walking around his deserted city, and thus being able to take in details for the first time:
The doorways were entrances into different cities no, different entrances into one vast, secret city. Ever close, adjacent to all you know, just underneath. If you know where to look.
And I can't fail to mention that you can almost touch Whitehead's sublimated hunger to eat out again as well:
Stickups were chops they cook fast and hot, you re in and out. A stakeout was ribs fire down low, slow, taking your time. [ ] Sometimes when Carney jumped into the Hudson when he was a kid, some of that stuff got into his mouth. The Big Apple Diner served it up and called it coffee.
More seriously, however, the relatively thin personalities of minor characters then reminded me of the simulacrum of Zoom-based relationships, and the essentially unsatisfactory endings to the novellas felt reminiscent of lockdown pseudo-events that simply fizzle out without a bang. One of the stories ties up loose ends with: 'These things were usually enough to terminate a mob war, and they appeared to end the hostilities in this case as well.' They did? Well, okay, I guess.
The corner of 125th Street and Morningside Avenue in 2019, the purported location of Carney's fictional furniture store. Signage plays a prominent role in Harlem Shuffle, possibly due to the author's quarantine walks.
Still, it would be unfair to characterise myself as 'disappointed' with the novel, and none of this piece should be taken as really deep criticism. The book certainly was entertaining enough, and pretty funny in places as well:
Carney didn t have an etiquette book in front of him, but he was sure it was bad manners to sit on a man s safe. [ ] The manager of the laundromat was a scrawny man in a saggy undershirt painted with sweat stains. Launderer, heal thyself.
Yet I can't shake the feeling that every book you write is a book that you don't, and so we might need to hold out a little longer for Whitehead's 'George Floyd novel'. (Although it is for others to say how much of this sentiment is the expectations of a White Reader for The Black Author to ventriloquise the pain of 'their' community.) Some room for personal critique is surely permitted. I dearly missed the junk food energy of the dry and acerbic observations that run through Whitehead's previous work. At one point he had a good line on the model tokenisation that lurks behind 'The First Negro to...' labels, but the callbacks to this idea ceased without any payoff. Similar things happened with the not-so-subtle critiques of the American Dream:
Entrepreneur? Pepper said the last part like manure. That s just a hustler who pays taxes. [ ] One thing I ve learned in my job is that life is cheap, and when things start getting expensive, it gets cheaper still.
Ultimately, though, I think I just wanted more. I wanted a deeper exploration of how the real power in New York is not wielded by individual street hoodlums or even the cops but in the form of real estate, essentially serving as a synecdoche for Capital as a whole. (A recent take of this can be felt in Jed Rothstein's 2021 documentary, WeWork: Or the Making and Breaking of a $47 Billion Unicorn and it is perhaps pertinent to remember that the US President at the time this novel was written was affecting to be a real estate tycoon.). Indeed, just like the concluding scenes of J. J. Connolly's Layer Cake, although you can certainly pull off a cool heist against the Man, power ultimately resides in those who control the means of production... and a homespun furniture salesman on the corner of 125 & Morningside just ain't that. There are some nods to kind of analysis in the conclusion of the final story ('Their heist unwound as if it had never happened, and Van Wyck kept throwing up buildings.'), but, again, I would have simply liked more. And when I attempted then file this book away into the broader media landscape, given the current cultural visibility of 1960s pop culture (e.g. One Night in Miami (2020), Judas and the Black Messiah (2021), Summer of Soul (2021), etc.), Harlem Shuffle also seemed like a missed opportunity to critically analyse our (highly-qualified) longing for the civil rights era. I can certainly understand why we might look fondly on the cultural products from a period when politics was less alienated, when society was less atomised, and when it was still possible to imagine meaningful change, but in this dimension at least, Harlem Shuffle seems to merely contribute to this nostalgic escapism.

15 September 2021

Ian Jackson: Get source to Debian packages only via dgit; "official" git links are beartraps

tl;dr dgit clone sourcepackage gets you the source code, as a git tree, in ./sourcepackage. cd into it and dpkg-buildpackage -uc -b. Do not use: "VCS" links on official Debian web pages like tracker.debian.org; "debcheckout"; searching Debian's gitlab (salsa.debian.org). These are good for Debian experts only. If you use Debian's "official" source git repo links you can easily build a package without Debian's patches applied.[1] This can even mean missing security patches. Or maybe it can't even be built in a normal way (or at all). OMG WTF BBQ, why? It's complicated. There is History. Debian's "most-official" centralised source repository is still the Debian Archive, which is a system based on tarballs and patches. I invented the Debian source package format in 1992/3 and it has been souped up since, but it's still tarballs and patches. This system is, of course, obsolete, now that we have modern version control systems, especially git. Maintainers of Debian packages have invented ways of using git anyway, of course. But this is not standardised. There is a bewildering array of approaches. The most common approach is to maintain git tree containing a pile of *.patch files, which are then often maintained using quilt. Yes, really, many Debian people are still using quilt, despite having git! There is machinery for converting this git tree containing a series of patches, to an "official" source package. If you don't use that machinery, and just build from git, nothing applies the patches. [1] This post was prompted by a conversation with a friend who had wanted to build a Debian package, and didn't know to use dgit. They had got the source from salsa via a link on tracker.d.o, and built .debs without Debian's patches. This not a theoretical unsoundness, but a very real practical risk. Future is not very bright In 2013 at the Debconf in Vaumarcus, Joey Hess, myself, and others, came up with a plan to try to improve this which we thought would be deployable. (Previous attempts had failed.) Crucially, this transition plan does not force change onto any of Debian's many packaging teams, nor onto people doing cross-package maintenance work. I worked on this for quite a while, and at a technical level it is a resounding success. Unfortunately there is a big limitation. At the current stage of the transition, to work at its best, this replacement scheme hopes that maintainers who update a package will use a new upload tool. The new tool fits into their existing Debian git packaging workflow and has some benefits, but it does make things more complicated rather than less (like any transition plan must, during the transitional phase). When maintainers don't use this new tool, the standardised git branch seen by users is a compatibility stub generated from the tarballs-and-patches. So it has the right contents, but useless history. The next step is to allow a maintainer to update a package without dealing with tarballs-and-patches at all. This would be massively more convenient for the maintainer, so an easy sell. And of course it links the tarballs-and-patches to the git history in a proper machine-readable way. We held a "git packaging requirements-gathering session" at the Curitiba Debconf in 2019. I think the DPL's intent was to try to get input into the git workflow design problem. The session was a great success: my existing design was able to meet nearly everyone's needs and wants. The room was obviously keen to see progress. The next stage was to deploy tag2upload. I spoke to various key people at the Debconf and afterwards in 2019 and the code has been basically ready since then. Unfortunately, deployment of tag2upload is mired in politics. It was blocked by a key team because of unfounded security concerns; positive opinions from independent security experts within Debian were disregarded. Of course it is always hard to get a team to agree to something when it's part of a transition plan which treats their systems as an obsolete setup retained for compatibility. Current status If you don't know about Debian's git packaging practices (eg, you have no idea what "patches-unapplied packaging branch without .pc directory" means), and don't want want to learn about them, you must use dgit to obtain the source of Debian packages. There is a lot more information and detailed instructions in dgit-user(7). Hopefully either the maintainer did the best thing, or, if they didn't, you won't need to inspect the history. If you are a Debian maintainer, you should use dgit push-source to do your uploads. This will make sure that users of dgit will see a reasonable git history.
edited 2021-09-15 14:48 Z to fix a typo


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14 September 2021

Sven Hoexter: PV - Monitoring Envertech Microinverter via envertecportal.com

Some time ago I looked briefly at an Envertech data logger for small scale photovoltaic setups. Turned out that PV inverter are kinda unreliable, and you really have to monitor them to notice downtimes and defects. Since my pal shot for a quick win I've cobbled together another Python script to query the portal at www.envertecportal.com, and report back if the generated power is down to 0. The script is currently run on a vserver via cron and reports back via the system MTA. So yeah, you need to have something like that already at hand. Script and Configuration You've to provide your PV systems location with latitude and longitude so the script can calculate (via python3-suntime) the sunrise and sunset times. At the location we deal with we expect to generate some power at least from sunrise + 1h to sunet - 1h. That is tunable via the configuration option toleranceSeconds. Retrieving the stationId is a bit ugly because it's not provided via any API, instead it's rendered serverside into the website. So I just logged in on the portal and picked it up by looking into the page source. www.envertecportal.com API I guess this is some classic in the IoT land, but neither the documentation provided on the portal frontpage as docx, nor the API docs at port 8090 are complete and correct. The few bits I gathered via the Firefox Web Developer Tools are:
  1. Login https://www.envertecportal.com/apiaccount/login - POST, sent userName and pwd containing your login name and password. The response JSON is very explicit if your login was not successful and why.
  2. Store the session cookie called ASP.NET_SessionId for use on all subsequent requests.
  3. Retrieve station info https://www.envertecportal.com/ApiStations/getStationInfo - POST, sent ASP.NET_SessionId and stationId with the ID of the station. Returns a JSON with an object named Data. The field Power contains the currently generated power as a float with two digits (e.g. 0.01).
  4. Logout https://www.envertecportal.com/apiAccount/Logout - POST, sent ASP.NET_SessionId.
Some Surprises There were a few surprises, maybe they help others dealing with an Envertech setup.
  1. The portal truncates passwords at 16 chars.
  2. The "Forget Password?" function mails you back the password in plain text (that's how I learned about 1.).
  3. The login API endpoint reporting the exact reason why the login failed is somewhat out of fashion. Though this one is probably not a credential stuffing target because there is no money to make, so don't care.
  4. The data logger reports the data to www.envertecportal.com at port 10013.
  5. There is some checksuming done on the reported data, but the system is not replay safe. So you can sent it any valid data string at a later time and get wrong data recorded.
  6. People at forum.fhem.de decoded some values but could not figure out the checksuming so far.

Jonathan Dowland: GHC rewrite rules

The Glasgow Haskell Compiler (GHC) has support for user-supplied rewrite rules, which applied during one of the compiler optimisation stages. An example rule is 
 -# RULES
      "streamFilter fuse" forall f g xs.
          streamFilter f (streamFilter g xs) = streamFilter (f.g) xs
  #-
I spent some time today looking at these more closely. In order for rewrite rules to be applied, optimisation needs to be enabled. This conflicts with interactive use of GHC, so you can't explore these things in GHCi. I think rewrite rules are enabled by default (with optimisation), but you can ask for them explicitly. When investigating these it's also useful to ask ghc to always recompile, otherwise you have to change the source or manually remove .hi or .o files (etc.) between invocations. A starting set of command-line options to use then, are 
-O -fenable-rewrite-rules -fforce-recomp
GHC runs several compilation stages, and the source program is transformed into several different languages or language dialects as it goes. Before the phase where rewrite rules are applied, some other optimisations take place, and the source gets desugared. You can see the results of the desugaring by passing the argument -ddump-ds. Here's an example program 
main = print (unStream (streamFilter (>3) (streamFilter (<10)
    (mkStream [0..20]))))
And here's what it looks like after the first pass optimisation and desugaring: 
main
  = print
      ($fShow[] $fShowInteger)
      (unStream
         (streamFilter
            (let  
               ds
               ds = 3   in
             \ ds -> > $fOrdInteger ds ds)
            (streamFilter
               (let  
                  ds
                  ds = 10   in
                \ ds -> < $fOrdInteger ds ds)
               (mkStream (enumFromTo $fEnumInteger 0 20)))))
(Note: I used -dsuppress-all and -dsuppress-uniques to improve the clarity of the above output. See Suppressing unwanted information for further details). Those short-hand sections ((<3)) in the input program are expanded to something quite a lot longer. Out of curiosity I tried it again with plain lambdas, not sections, and the result was smaller 
main
  = print
      ($fShow[] $fShowInteger)
      (unStream
         (streamFilter
            (\ x -> > $fOrdInteger x 3)
            (streamFilter
               (\ x -> < $fOrdInteger x 10)
               (mkStream (enumFromTo $fEnumInteger 0 20)))))
Rewrite rules happen after this. Once they're done (and several other passes), the program is translated into an intermediate representation called Tiny Core. This language faintly resembles the input Haskell. GHC will output the Tiny Core program if you supply the argument -ddump-simpl. Here's (most) of the program in Tiny Core (I've substituted some constants for clarity): 
main  = hPutStr' stdout main1 True
main1 = $fShowInteger_$cshowList (catMaybes1 (main_go 0)) []
main_go
  = \ x ->
      case gtInteger# x 20 of  
        DEFAULT ->
          case ltInteger# x 10 of  
            DEFAULT -> main_go (plusInteger x 1);
            1# ->
              case gtInteger# x 3 of  
                DEFAULT -> main_go (plusInteger x 1);
                1# -> : (Just x) (main_go (plusInteger x 1))
               
           ;
        1# -> []
After Tiny Core, GHC continues to translate the program into other forms (including STG, CMM, ASM) and you can ask GHC to dump those representations too, but this is all downstream from the rewrites so not relevant to them. The rewrite rule at the top of this blog post is never applied: It doesn't get a chance, because the function it operates on (streamFilter) is inlined by GHC. GHC can detect this in some circumstances (-Winline-rule-shadowing). You instruct GHC to report on which rules fired with -ddump-rule-firings and can see before-and-after snippets of Tiny Core for each rule applied with -ddump-rule-rewrites. I played around with adding -# NOINLINE functionName #- pragmas to disable inlining various functions to try and provoke a situation where the above rule could match, but it was a losing battle: GHC's built-in optimisations are just too good. But, it's also moot: the outcome I want (the filters to be fused) is happening, it's just the built-in rewrite rules are achieving it, once striot's functions have been inlined away.

12 September 2021

Russ Allbery: DocKnot 5.00

This release is the culmination of a project that I've been wanting to do for two years, but nearly all the work was done in the past week. That experience made me rethink some of my skepticism, but I'll get to that part of the story later. In March of 1999, I got tired of writing HTML by hand and wrote a small program called spin that implemented a macro language that translated into HTML. This makes it one of the oldest programs for which I have a continuous development history, predating podlators by three months. I think only News::Gateway (now very dormant) and Term::ANSIColor (still under active development but very stable) are older, as long as I'm not counting orphaned packages like newsyslog. I've used spin continuously ever since. It's grown features and an ecosystem of somewhat hackish scripts to do web publishing things I've wanted over the years: journal entries like this one, book reviews, a simple gallery (with some now-unfortunate decisions about maximum image size), RSS feeds, and translation of lots of different input files into HTML. But the core program itself, in all those years, has been one single Perl script written mostly in my Perl coding style from the early 2000s before I read Perl Best Practices. My web site is long overdue for an overhaul. Just to name a couple of obvious problems, it looks like trash on mobile browsers, and I'm using URL syntax from the early days of the web that, while it prompts some nostalgia for tildes, means all the URLs are annoyingly long and embed useless information such as the fact each page is written in HTML. Its internals also use a lot of ad hoc microformats (a bit of RFC 2822 here, a text-based format with significant indentation there, a weird space-separated database) and are supported by programs that extract meaning from human-written pages and perform automated updates to them rather than having a clear separation between structure and data. This will be a very large project, but it's the sort of quixotic personal project that I enjoy. Maintaining my own idiosyncratic static site generator is almost certainly not an efficient use of my time compared to, say, converting everything to Hugo. But I have 3,428 pages (currently) written in the thread macro language, plus numerous customizations that cater to my personal taste and interests, and, most importantly, I like having a highly customized system that I know exactly how to automate. The blocker has been that I didn't want to work on spin as it existed. It badly needed a structural overhaul and modernization, and even more badly needed a test suite since every release involved tedious manual testing by pouring over diffs between generations of the web site. And that was enough work to be intimidating, so I kept putting it off. I've separately been vaguely aware that I have been spending too much time reading Twitter (specifically) and the news (in general). It would be one thing if I were taking in that information to do something productive about it, but I haven't been. It's just doomscrolling. I've been thinking about taking a break for a while but it kept not sticking, so I decided to make a concerted effort this week. It took about four days to stop wanting to check Twitter and forcing myself to go do something else productive or at least play a game instead. Then I managed to get started on my giant refactoring project, and holy shit, Twitter has been bad for my attention span! I haven't been able to sustain this level of concentration for hours at a time in years. Twitter's not the only thing to blame (there are a few other stressers that I've fixed in the past couple of years), but it's obviously a huge part. Anyway, this long personal ramble is prelude to the first release of DocKnot that includes my static site generator. This is not yet the full tooling from my old web tools page; specifically, it's missing faq2html, cl2xhtml, and cvs2xhtml. (faq2html will get similar modernization treatment, cvs2xhtml will probably be rewritten in Perl since I have some old, obsolete scripts that may live in CVS forever, and I may retire cl2xhtml since I've stopped using the GNU ChangeLog format entirely.) But DocKnot now contains the core of my site generation system, including the thread macro language, POD conversion (by way of Pod::Thread), and RSS feeds. Will anyone else ever use this? I have no idea; realistically, probably not. If you were starting from scratch, I'm sure you'd be better off with one of the larger and more mature static site generators that's not the idiosyncratic personal project of one individual. It is packaged for Debian because it's part of the tool chain for generating files (specifically README.md) that are included in every package I maintain, and thus is part of the transitive closure of Debian main, but I'm not sure anyone will install it from there for any other purpose. But for once making something for someone else isn't the point. This is my quirky, individual way to maintain web sites that originated in an older era of the web and that I plan to keep up-to-date (I'm long overdue to figure out what they did to HTML after abandoning the XHTML approach) because it brings me joy to do things this way. In addition to adding the static site generator, this release also has the regular sorts of bug fixes and minor improvements: better formatting of software pages for software that's packaged for Debian, not assuming every package has a TODO file, and ignoring Autoconf 2.71 backup files when generating distribution tarballs. You can get the latest version of DocKnot from CPAN as App-DocKnot, or from its distribution page. I know I haven't yet updated my web tools page to reflect this move, or changed the URL in the footer of all of my pages. This transition will be a process over the next few months and will probably prompt several more minor releases.

Vincent Bernat: Short feedback on Cisco pyATS and Genie Parser

Cisco pyATS is a framework for network automation and testing. It includes, among other things, an open-source multi-vendor set of parsers and models, Genie Parser. It features 2700 parsers for various commands over many network OS. On the paper, this seems a great tool! 
>>> from genie.conf.base import Device
>>> device = Device("router", os="iosxr")
>>> # Hack to parse outputs without connecting to a device
>>> device.custom.setdefault("abstraction",  )["order"] = ["os", "platform"]
>>> cmd = "show route ipv4 unicast"
>>> output = """
... Tue Oct 29 21:29:10.924 UTC
...
... O    10.13.110.0/24 [110/2] via 10.12.110.1, 5d23h, GigabitEthernet0/0/0/0.110
... """
>>> device.parse(cmd, output=output)
 'vrf':  'default':  'address_family':  'ipv4':  'routes':  '10.13.110.0/24':  'route': '10.13.110.0/24',
       'active': True,
       'route_preference': 110,
       'metric': 2,
       'source_protocol': 'ospf',
       'source_protocol_codes': 'O',
       'next_hop':  'next_hop_list':  1:  'index': 1,
          'next_hop': '10.12.110.1',
          'outgoing_interface': 'GigabitEthernet0/0/0/0.110',
          'updated': '5d23h'
First deception: pyATS is closed-source with some exceptions. This is quite annoying if you run into some issues outside Genie Parser. For example, although pyATS is using the ssh command, it cannot leverage my ssh_config file: pyATS resolves hostnames before providing them to ssh. There is no plan to open source pyATS. Then, Genie Parser has two problems:
  1. The data models used are dependent on the vendor and OS, despite the documentation saying otherwise. For example, the data model used for IPv4 interfaces is different between NX-OS and IOS-XR.
  2. The parsers rely on line-by-line regular expressions to extract data and some Python code as glue. This is fragile and may break silently.
To illustrate the second point, let s assume the output of show ipv4 vrf all interface is: 
  Loopback10 is Up, ipv4 protocol is Up
    Vrf is default (vrfid 0x60000000)
    Internet protocol processing disabled
  Loopback30 is Up, ipv4 protocol is Down [VRF in FWD reference]
    Vrf is ran (vrfid 0x0)
    Internet address is 203.0.113.17/32
    MTU is 1500 (1500 is available to IP)
    Helper address is not set
    Directed broadcast forwarding is disabled
    Outgoing access list is not set
    Inbound  common access list is not set, access list is not set
    Proxy ARP is disabled
    ICMP redirects are never sent
    ICMP unreachables are always sent
    ICMP mask replies are never sent
    Table Id is 0x0
Because the regular expression to parse an interface name does not expect the extra data after the interface state, Genie Parser ignores the line starting the definition of Loopback30 and parses the output to this structure:1 
 
  "Loopback10":  
    "int_status": "up",
    "oper_status": "up",
    "vrf": "ran",
    "vrf_id": "0x0",
    "ipv4":  
      "203.0.113.17/32":  
        "ip": "203.0.113.17",
        "prefix_length": "32"
       ,
      "mtu": 1500,
      "mtu_available": 1500,
      "broadcast_forwarding": "disabled",
      "proxy_arp": "disabled",
      "icmp_redirects": "never sent",
      "icmp_unreachables": "always sent",
      "icmp_replies": "never sent",
      "table_id": "0x0"
While this bug is simple to fix, this is an uphill battle. Any existing or future slight variation in the output of a command could trigger another similar undetected bug, despite the extended test coverage. I have reported and fixed several other silent parsing errors: #516, #529, and #530. A more robust alternative would have been to use TextFSM and to trigger a warning when some output is not recognized, like Batfish, a configuration analysis tool, does. In the future, we should rely on YANG for data extraction, but it is currently not widely supported. SNMP is still a valid possibility but much information is not accessible through this protocol. In the meantime, I would advise you to only use Genie Parser with caution.
  1. As an exercise, the astute reader is asked to write the code to extract the IPv4 from this structure.

10 September 2021

Enrico Zini: A nightmare of confcalls and microphones

I had this nightmare where I had a very, very important confcall. I joined with Chrome. Chrome said Failed to access your microphone - Cannot use microphone for an unknown reason. Could not start audio source. I joined with Firefox. Firefox chose Monitor of Built-in Audio Analog Stereo as a microphone, and did not let me change it. Not in the browser, not in pavucontrol. I joined with the browser on my phone, and the webpage said This meeting needs to use your microphone and camera. Select *Allow* when your browser asks for permissions. But the question never came. I could hear people talking. I had very important things to say. I tried typing them in the chat window, but they weren't seeing it. The meeting ended. I was on the verge of tears.
Tell me, Mr. Anderson, what good is a phone call when you are unable to speak?
Since this nightmare happened for real, including the bit about tears in the end, let's see that it doesn't happen again. I should now have three working systems, which hopefully won't all break again all at the same time. Fixing Chrome I can reproduce this reliably, on Bullseye's standard Chromium 90.0.4430.212-1, just launched on an empty profile, no extensions. The webpage has camera and microphone allowed. Chrome doesn't show up in the recording tab of pulseaudio. Nothing on Chrome's stdout/stderr. JavaScript console has: 
Logger.js:154 2021-09-10Txx:xx:xx.xxxZ [features/base/tracks] Failed to create local tracks
Array(2)
DOMException: Could not start audio source
I found the answer here:
I had the similar problem once with chromium. i could solve it by switching in preferences->microphone-> from "default" to "intern analog stereo".
Opening the little popup next to the microphone/mute button allows choosing other microphones, which work. Only "Same as system (Default)" does not work. Fixing Firefox I have firefox-esr 78.13.0esr-1~deb11u1. In Jitsi, microphone selection is disabled on the toolbar and in the settings menu. In pavucontrol, changing the recording device for Firefox has no effect. If for some reason the wrong microphone got chosen, those are not ways of fixing it. What I found works is to click on the camera permission icon, remove microphone permission, then reload the page. At that point Firefox will ask for permission again, and that microphone selection seems to work. Relevant bugs: on Jitsi and on Firefox. Since this is well known (once you find the relevant issues), I'd have appreciated Jitsi at least showing a link to an explanation of workarounds on Firefox, instead of just disabling microphone selection. Fixing Jitsi on the phone side I really don't want to preemptively give camera and microphone permissions to my phone browser. I noticed that there's the Jitsi app on F-Droid and much as I hate to use an app when a website would work, at least in this case it's a way to keep the permission sets separate, so I installed that. Fixing pavucontrol? I tried to find out why I can't change input device for FireFox on pavucontrol. I only managed to find an Ask Ubuntu question with no answer and a Unix StackExchange question with no answer.

9 September 2021

Bits from Debian: DebConf21 online closes

DebConf21 group photo - click to enlarge On Saturday 28 August 2021, the annual Debian Developers and Contributors Conference came to a close. DebConf21 has been held online for the second time, due to the coronavirus (COVID-19) disease pandemic. All of the sessions have been streamed, with a variety of ways of participating: via IRC messaging, online collaborative text documents, and video conferencing meeting rooms. With 740 registered attendees from more than 15 different countries and a total of over 70 event talks, discussion sessions, Birds of a Feather (BoF) gatherings and other activities, DebConf21 was a large success. The setup made for former online events involving Jitsi, OBS, Voctomix, SReview, nginx, Etherpad, a web-based frontend for voctomix has been improved and used for DebConf21 successfully. All components of the video infrastructure are free software, and configured through the Video Team's public ansible repository. The DebConf21 schedule included a wide variety of events, grouped in several tracks: The talks have been streamed using two rooms, and several of these activities have been held in different languages: Telugu, Portuguese, Malayalam, Kannada, Hindi, Marathi and English, allowing a more diverse audience to enjoy and participate. Between talks, the video stream has been showing the usual sponsors on the loop, but also some additional clips including photos from previous DebConfs, fun facts about Debian and short shout-out videos sent by attendees to communicate with their Debian friends. The Debian publicity team did the usual live coverage to encourage participation with micronews announcing the different events. The DebConf team also provided several mobile options to follow the schedule. For those who were not able to participate, most of the talks and sessions are already available through the Debian meetings archive website, and the remaining ones will appear in the following days. The DebConf21 website will remain active for archival purposes and will continue to offer links to the presentations and videos of talks and events. Next year, DebConf22 is planned to be held in Prizren, Kosovo, in July 2022. DebConf is committed to a safe and welcome environment for all participants. During the conference, several teams (Front Desk, Welcome team and Community team) have been available to help so participants get their best experience in the conference, and find solutions to any issue that may arise. See the web page about the Code of Conduct in DebConf21 website for more details on this. Debian thanks the commitment of numerous sponsors to support DebConf21, particularly our Platinum Sponsors: Lenovo, Infomaniak, Roche, Amazon Web Services (AWS) and Google. About Debian The Debian Project was founded in 1993 by Ian Murdock to be a truly free community project. Since then the project has grown to be one of the largest and most influential open source projects. Thousands of volunteers from all over the world work together to create and maintain Debian software. Available in 70 languages, and supporting a huge range of computer types, Debian calls itself the universal operating system. About DebConf DebConf is the Debian Project's developer conference. In addition to a full schedule of technical, social and policy talks, DebConf provides an opportunity for developers, contributors and other interested people to meet in person and work together more closely. It has taken place annually since 2000 in locations as varied as Scotland, Argentina, and Bosnia and Herzegovina. More information about DebConf is available from https://debconf.org/. About Lenovo As a global technology leader manufacturing a wide portfolio of connected products, including smartphones, tablets, PCs and workstations as well as AR/VR devices, smart home/office and data center solutions, Lenovo understands how critical open systems and platforms are to a connected world. About Infomaniak Infomaniak is Switzerland's largest web-hosting company, also offering backup and storage services, solutions for event organizers, live-streaming and video on demand services. It wholly owns its datacenters and all elements critical to the functioning of the services and products provided by the company (both software and hardware). About Roche Roche is a major international pharmaceutical provider and research company dedicated to personalized healthcare. More than 100.000 employees worldwide work towards solving some of the greatest challenges for humanity using science and technology. Roche is strongly involved in publicly funded collaborative research projects with other industrial and academic partners and have supported DebConf since 2017. About Amazon Web Services (AWS) Amazon Web Services (AWS) is one of the world's most comprehensive and broadly adopted cloud platform, offering over 175 fully featured services from data centers globally (in 77 Availability Zones within 24 geographic regions). AWS customers include the fastest-growing startups, largest enterprises and leading government agencies. About Google Google is one of the largest technology companies in the world, providing a wide range of Internet-related services and products such as online advertising technologies, search, cloud computing, software, and hardware. Google has been supporting Debian by sponsoring DebConf for more than ten years, and is also a Debian partner sponsoring parts of Salsa's continuous integration infrastructure within Google Cloud Platform. Contact Information For further information, please visit the DebConf21 web page at https://debconf21.debconf.org/ or send mail to press@debian.org.

8 September 2021

Thorsten Alteholz: My Debian Activities in August 2021

FTP master Yeah, Bullseye is released, thanks a lot to everybody involved! This month I accepted 242 and rejected 18 packages. The overall number of packages that got accepted was 253. Debian LTS This was my eighty-sixth month that I did some work for the Debian LTS initiative, started by Raphael Hertzog at Freexian. This month my all in all workload has been 23.75h. During that time I did LTS and normal security uploads of: I also started to work on openssl, grilo and had to process packages from NEW on security-master. As the CVE of btrbk was later marked as no-dsa, an upload to stable and oldstable is needed now. Last but not least I did some days of frontdesk duties. Debian ELTS This month was the thirty-eighth ELTS month. During my allocated time I uploaded: I also started to work on openssl. Last but not least I did some days of frontdesk duties. Other stuff This month I uploaded new upstream versions of: On my neverending golang challenge I again uploaded some packages either for NEW or as source upload.

7 September 2021

Martin-&#201;ric Racine: sudo apt-get update && sudo apt-get dist-upgrade

Debian 11 (codename Bullseye) was recently released. This was the smoothest upgrade I've experienced in some 20 years as a Debian user. In my haste, I completely forgot to first upgrade dpkg and apt, doing a straight dist-upgrade. Nonetheless, everything worked out of the box. No unresolved dependency cycles. Via my last-mile Gigabit connection, it took about 5 minutes to upgrade and reboot. Congratulations to everyone who made this possible! Since the upgrade, only a handful of bugs were found. I filed bug reports. Over these past few days, maintainers have started responding. In once particular case, my report exposed a CVE caused by copy-pasted code between two similar packages. The source package fixed their code to something more secure a few years ago, while the destination package missed it. The situation has been brought to Debian's security team's attention and should be fixed over the next few days. Afterthoughts Having recently experienced hard-disk problems on my main desktop, upgrading to Bullseye made me revisit a few issues. One of these was the possibility of transiting to BTRFS. Last time I investigated the possibility was back when Ubuntu briefly switched their default filesystem to BRTFS. Back then, my feeling was that BRTFS wasn't ready for mainstream. For instance, the utility to convert an EXT2/3/4 partition to BTRFS corrupted the end of the partition. No thanks. However, in recent years, many large-scale online services have migrated to BRTFS and seem to be extremely happy with the result. Additionally, Linux kernel 5 added useful features such as background defragmentation. This got me pondering whether now would be a good time to migrate to BRTFS. Sadly it seems that the stock kernel shipping with Bullseye doesn't have any of these advanced features enabled in its configuration. Oh well. Geode The only point that has become problematic is my Geode hosts. For one things, upstream Rust maintainers have decided to ignore the fact that i686 is a specification and arbitrarily added compiler flags for more recent x86-32 CPUs to their i686 target. While Debian Rust maintainers have purposely downgraded the target, RustC still produces binaries that the Geode LX (essentially an i686 without PAE) cannot process. This affects fairly basic packages such as librsvg, which breaks SVG image support for a number of dependencies. Additionally, there's been persistent problems with systemd crashing on my Geode hosts whenever daemon-reload is issued. Then, a few days ago, problems started occurring with C++ binaries, because GCC-11 upstream enabled flags for more recent CPUs in their default i686 target. While I realize that SSE and similar recent CPU features produce better binaries, I cannot help but feel that treating CPU targets as anything else than a specification is a mistake. i686 is a specification. It is not a generic equivalent to x86-32.

Russell Coker: Oracle Cloud Free Tier

It seems that every cloud service of note has a free tier nowadays and the Oracle Cloud is the latest that I ve discovered (thanks to r/homelab which I highly recommend reading). Here s Oracle s summary of what they offer for free [1]. Oracle s always free tier (where presumable always is defined as until we change our contract ) currently offers ARM64 VMs to a total capacity of 4 CPU cores, 24G of RAM, and 200G of storage with a default VM size of 1/4 that (1 CPU core and 6G of RAM). It also includes 2 AMD64 VMs that each have 1G of RAM, but a 64bit VM with 1G of RAM isn t that useful nowadays. Web Interface The first thing to note is that the management interface is a massive pain to use. When a login times out for security reasons it redirects to a web page that gives a 404 error, maybe the redirection works OK if you are using it when it times out, but if you go off and spend an hour doing something else you will return to a 404 page. A web interface should never refer you to a page with a 404. There doesn t seem to be a way of bookmarking the commonly used links (as AWS does) and the set of links on the left depend on the section you are in with no obvious way of going between sections. Sometimes I got stuck in a set of pages about authentication controls (the identity cloud ) and there seems to be no link I could click on to get me back to cloud computing, I had to go to a bookmarked link for the main cloud login page. A web interface should never force the user to type in the main URL or go to a bookmark, you should be able to navigate from every page to every other page in a logical manner. An advanced user might have their own bookmarks in their browser to suit their workflow. But a beginner should be able to go to anywhere without breaking the session. Some parts of the interface appear to be copied from AWS, but unfortunately not the good parts. The way AWS manages IP access control is not easy to manage and it s not clear why packets are dropped, Oracle copies all this. On the upside Oracle has some good Datadog style analytics so for a new deployment you can debug IP access control by seeing records of rejected packets. Just to make it extra annoying when you create a rule with multiple ports specified the web interface will expand it out to multiple rules for one port each, having ports 80 and 443 on separate lines doesn t make things easier. Also it forces you to have IPv4 and IPv6 as separate rules, so if you want HTTP and HTTPS on both IPv4 and IPv6 (a common requirement) then you need 4 separate rules. One final annoying thing is that the web interface doesn t make your previous settings a default. As I ve created many ARM images and haven t created a single AMD image it should know that the probability that I want to create an AMD image is very low and stop defaulting to that. Recovery When trying a new system you will inevitably break things and have to recover things. The way to recover from a configuration error that prevents your VM from booting and getting to a state of allowing a login is to go to stop the VM, then go to the Boot volume section under Resources and use the settings button to detach the boot volume. Then you go to another VM (which must be running), go to the Attached block volumes menu and attach it as Paravirtualised (not iSCSI and not default which will probably be iSCSI). After some time the block device will appear and you can mount it and do stuff to it. Then after umounting it you detach it from the recovery VM and attach it again to the original VM (where it will still have an entry in the Boot volume section) and boot the original VM. As an aside it s really annoying that you can t attach a volume to a VM that isn t running. My first attempt at image recovery started with making a snapshot of the Boot volume, this didn t work well because the image uses EFI and therefore GPT and because the snapshot was larger than the original block device (which incidentally was the default size). I admit that I might have made a mistake making the snapshot, but if so it shouldn t be so easy to do. With GPT if you have a larger block device then partitioning tools complain about the backup partition table not being found, and they complain even more if you try to go back to the smaller size later on. Generally GPT partition tables are a bad idea for VMs, when I run the host I don t use partition tables, I have a separate block device for each filesystem or swap space. Snapshots aren t needed for recovery, they don t seem to work very well, and if it s possible to attach a snapshot to a VM in place of it s original Boot volume I haven t figured out how to do it. Console Connection If you boot Oracle Linux a derivative of RHEL that has SE Linux enabled in enforcing mode (yay) then you can go to the Console connection . The console is a Javascript console which allows you to login on a virtual serial console on device /dev/ttyAMA0. It tells you to type help but that isn t accepted, you have a straight Linux console login prompt. If you boot Ubuntu then you don t get a working serial console, it tells you to type help for help but doesn t respond to that. It seems that the Oracle Linux kernel 5.4.17-2102.204.4.4.el7uek.aarch64 is compiled with support for /dev/ttyAMA0 (the default ARM serial device) while the kernel 5.11.0-1016-oracle compiled by Oracle for their Ubuntu VMs doesn t have it. Performance I haven t done any detailed tests of VM performance. As a quick test I used zstd to compress a 154MB file, on my home workstation (E5-2620 v4 @ 2.10GHz) it took 11.3 seconds of CPU time to compress with zstd -9 and 7.2s to decompress. On the Oracle cloud it took 7.2s and 5.4s. So it seems that for some single core operations the ARM CPU used by the Oracle cloud is about 30% to 50% faster than a E5-2620 v4 (a slightly out of date server processor that uses DDR4 RAM). If you ran all the free resources in a single VM that would make a respectable build server. If you want to contribute to free software development and only have a laptop with 4G of RAM then an ARM build/test server with 24G of RAM and 4 cores would be very useful. Ubuntu Configuration The advantage of using EFI is that you can manage the kernel from within the VM. The default Oracle kernel for Ubuntu has a lot of modules included and is compiled with a lot of security options including SE Linux. Competitors https://aws.amazon.com/free AWS offers 750 hours (just over 31 days) per month of free usage of a t2.micro or t3.micro EC2 instance (which means 1GB of RAM). But that only lasts for 12 months and it s still only 1GB of RAM. AWS has some other things that could be useful like 1 million free Lambda requests per month. If you want to run your personal web site on Lambda you shouldn t hit that limit. They also apparently have some good offers for students. https://cloud.google.com/free The Google Cloud Project (GCP) offers $300 of credit. https://cloud.google.com/free/docs/gcp-free-tier#free-tier-usage-limits GCP also has ongoing free tier usage for some services. Some of them are pretty much unlimited use (50GB of storage for Cloud Source Repositories is a heap of source code). But for VMs you get the equivalent of 1*e2-micro instance running 24*7. A e2-micro has 1G of RAM. You also only get 30G of storage and 1GB of outbound data. It s clearly not as generous an offer as Oracle, but Oracle is the underdog so they have to try harder. https://azure.microsoft.com/en-us/free/ Azure appears to be much the same as AWS, free Linux VM for a year and then other less popular services free forever (or until they change the contract). https://www.ibm.com/cloud/free The IBM cloud free tier is the least generous offer, a VM is only free for 30 days. But what they offer for 30 days is pretty decent. If you want to try the IBM cloud and see if it can do what your company needs then this will do well. If you want to have free hosting for your hobby stuff then it s no good. Oracle seems like the most generous offer if you want to do stuff, but also one of the least valuable if you want to learn things that will help you at a job interview. For job interviews AWS seems the most useful and then GCP and Azure vying for second place.
Related posts:
  1. Oracle Unbreakable Linux Matt Bottrell writes about the Oracle Linux offerings presented at...
  2. Types of Cloud Computing The term Cloud Computing seems to be poorly defined at...
  3. Could we have an Open Computing Cloud? One of the most interesting new technologies that has come...

6 September 2021

Jelmer Vernooij: Web Hooks for the Janitor

The Debian Janitor is an automated system that commits fixes for (minor) issues in Debian packages that can be fixed by software. It gradually started proposing merges in early December. The first set of changes sent out ran lintian-brush on sid packages maintained in Git. This post is part of a series about the progress of the Janitor. As covered in my post from last week, the Janitor now regularly tries to import new upstream git snapshots or upstream releases into packages in Sid.

Moving parts There are about 30,000 packages in sid, and it usually takes a couple of weeks for the janitor to cycle through all of them. Generally speaking, there are up to three moving targets for each package:
  • The packaging repository; vcswatch regularly scans this for changes, and notifies the janitor when a repository has changed. For salsa repositories it is instantly notified through a web hook
  • The upstream release tarballs; the QA watch service regularly polls these, and the janitor scans for changes in the UDD tables with watch data (used for fresh-releases)
  • The upstream repository; there is no service in Debian that watches this at the moment (used for fresh-snapshots)
When the janitor notices that one of these three targets has changed, it prioritizes processing of a package - this means that a push to a packaging repository on salsa usually leads to a build being kicked off within 10 minutes. New upstream releases are usually noticed by QA watch within a day or so and then lead to a build. Now commits in upstream repositories don t get noticed today. Note that there are no guarantees; the scheduler tries to be clever and not e.g. rebuild the same package over and over again if it s constantly changing and takes a long time to build. Packages without priority are processed with a scoring system that takes into account perceived value (based on e.g. popcon), cost (based on wall-time duration of previous builds) and likelihood of success (whether recent builds were successful, and how frequently the repositories involved change).
webhooks for upstream repositories At the moment there is no service in Debian (yet - perhaps this is something that vcswatch or a sibling service could also do?) that scans upstream repositories for changes. However, if you maintain an upstream package, you can use a webhook to notify the janitor that commits have been made to your repository, and it will create a new package in fresh-snapshots. Webhooks from the following hosting site software are currently supported: You can simply use the URL https://janitor.debian.net/ as the target for hooks. There is no need to specify a secret, and the hook can either use a JSON or form encoding payload. The endpoint should tell you whether it understood a webhook request, and whether it took any action. It s fine to submit webhooks for repositories that the janitor does not (yet) know about.
GitHub For GitHub, you can do so in the Webhooks section of the Settings tab. Fill the form as shown below and click on Add webhook:
GitLab On GitLab instances, you can find the Webhooks tab under the Settings menu for each repository (under the gear symbol). Fill the form in as shown below and click Add Webhook:
Launchpad For Launchpad, go to the repository (for Git) web view and click Manage Webhooks. From there, you can add a new webhook; fill the form in as shown below and click Add Webhook:

Vincent Bernat: Switching to the i3 window manager

I have been using the awesome window manager for 10 years. It is a tiling window manager, configurable and extendable with the Lua language. Using a general-purpose programming language to configure every aspect is a double-edged sword. Due to laziness and the apparent difficulty of adapting my configuration about 3000 lines to newer releases, I was stuck with the 3.4 version, whose last release is from 2013. It was time for a rewrite. Instead, I have switched to the i3 window manager, lured by the possibility to migrate to Wayland and Sway later with minimal pain. Using an embedded interpreter for configuration is not as important to me as it was in the past: it brings both complexity and brittleness.
i3 dual screen setup
Dual screen desktop running i3, Emacs, some terminals, including a Quake console, Firefox, Polybar as the status bar, and Dunst as the notification daemon.
The window manager is only one part of a desktop environment. There are several options for the other components. I am also introducing them in this post.

i3: the window manager i3 aims to be a minimal tiling window manager. Its documentation can be read from top to bottom in less than an hour. i3 organize windows in a tree. Each non-leaf node contains one or several windows and has an orientation and a layout. This information arbitrates the window positions. i3 features three layouts: split, stacking, and tabbed. They are demonstrated in the below screenshot:
Example of layouts
Demonstration of the layouts available in i3. The main container is split horizontally. The first child is split vertically. The second one is tabbed. The last one is stacking.
Tree representation of the previous screenshot
Tree representation of the previous screenshot.
Most of the other tiling window managers, including the awesome window manager, use predefined layouts. They usually feature a large area for the main window and another area divided among the remaining windows. These layouts can be tuned a bit, but you mostly stick to a couple of them. When a new window is added, the behavior is quite predictable. Moreover, you can cycle through the various windows without thinking too much as they are ordered. i3 is more flexible with its ability to build any layout on the fly, it can feel quite overwhelming as you need to visualize the tree in your head. At first, it is not unusual to find yourself with a complex tree with many useless nested containers. Moreover, you have to navigate windows using directions. It takes some time to get used to. I set up a split layout for Emacs and a few terminals, but most of the other workspaces are using a tabbed layout. I don t use the stacking layout. You can find many scripts trying to emulate other tiling window managers but I did try to get my setup pristine of these tentatives and get a chance to familiarize myself. i3 can also save and restore layouts, which is quite a powerful feature. My configuration is quite similar to the default one and has less than 200 lines.

i3 companion: the missing bits i3 philosophy is to keep a minimal core and let the user implements missing features using the IPC protocol:
Do not add further complexity when it can be avoided. We are generally happy with the feature set of i3 and instead focus on fixing bugs and maintaining it for stability. New features will therefore only be considered if the benefit outweighs the additional complexity, and we encourage users to implement features using the IPC whenever possible. Introduction to the i3 window manager
While this is not as powerful as an embedded language, it is enough for many cases. Moreover, as high-level features may be opinionated, delegating them to small, loosely coupled pieces of code keeps them more maintainable. Libraries exist for this purpose in several languages. Users have published many scripts to extend i3: automatic layout and window promotion to mimic the behavior of other tiling window managers, window swallowing to put a new app on top of the terminal launching it, and cycling between windows with Alt+Tab. Instead of maintaining a script for each feature, I have centralized everything into a single Python process, i3-companion using asyncio and the i3ipc-python library. Each feature is self-contained into a function. It implements the following components:
make a workspace exclusive to an application
When a workspace contains Emacs or Firefox, I would like other applications to move to another workspace, except for the terminal which is allowed to intrude into any workspace. The workspace_exclusive() function monitors new windows and moves them if needed to an empty workspace or to one with the same application already running.
implement a Quake console
The quake_console() function implements a drop-down console available from any workspace. It can be toggled with Mod+ . This is implemented as a scratchpad window.
back and forth workspace switching on the same output
With the workspace back_and_forth command, we can ask i3 to switch to the previous workspace. However, this feature is not restricted to the current output. I prefer to have one keybinding to switch to the workspace on the next output and one keybinding to switch to the previous workspace on the same output. This behavior is implemented in the previous_workspace() function by keeping a per-output history of the focused workspaces.
create a new empty workspace or move a window to an empty workspace
To create a new empty workspace or move a window to an empty workspace, you have to locate a free slot and use workspace number 4 or move container to workspace number 4. The new_workspace() function finds a free number and use it as the target workspace.
restart some services on output change
When adding or removing an output, some actions need to be executed: refresh the wallpaper, restart some components unable to adapt their configuration on their own, etc. i3 triggers an event for this purpose. The output_update() function also takes an extra step to coalesce multiple consecutive events and to check if there is a real change with the low-level library xcffib.
I will detail the other features as this post goes on. On the technical side, each function is decorated with the events it should react to: 
@on(CommandEvent("previous-workspace"), I3Event.WORKSPACE_FOCUS)
async def previous_workspace(i3, event):
    """Go to previous workspace on the same output."""
The CommandEvent() event class is my way to send a command to the companion, using either i3-msg -t send_tick or binding a key to a nop command. The latter is used to avoid spawning a shell and a i3-msg process just to send a message. The companion listens to binding events and checks if this is a nop command. 
bindsym $mod+Tab nop "previous-workspace"
There are other decorators to avoid code duplication: @debounce() to coalesce multiple consecutive calls, @static() to define a static variable, and @retry() to retry a function on failure. The whole script is a bit more than 1000 lines. I think this is worth a read as I am quite happy with the result.

dunst: the notification daemon Unlike the awesome window manager, i3 does not come with a built-in notification system. Dunst is a lightweight notification daemon. I am running a modified version with HiDPI support for X11 and recursive icon lookup. The i3 companion has a helper function, notify(), to send notifications using DBus. container_info() and workspace_info() uses it to display information about the container or the tree for a workspace.
Notification showing i3 tree for a workspace
Notification showing i3 s tree for a workspace

polybar: the status bar i3 bundles i3bar, a versatile status bar, but I have opted for Polybar. A wrapper script runs one instance for each monitor. The first module is the built-in support for i3 workspaces. To not have to remember which application is running in a workspace, the i3 companion renames workspaces to include an icon for each application. This is done in the workspace_rename() function. The icons are from the Font Awesome project. I maintain a mapping between applications and icons. This is a bit cumbersome but it looks great.
i3 workspaces in Polybar
i3 workspaces in Polybar
For CPU, memory, brightness, battery, disk, and audio volume, I am relying on the built-in modules. Polybar s wrapper script generates the list of filesystems to monitor and they get only displayed when available space is low. The battery widget turns red and blinks slowly when running out of power. Check my Polybar configuration for more details.
Various modules for Polybar
Polybar displaying various information: CPU usage, memory usage, screen brightness, battery status, Bluetooth status (with a connected headset), network status (connected to a wireless network and to a VPN), notification status, and speaker volume.
For Bluetooh, network, and notification statuses, I am using Polybar s ipc module: the next version of Polybar can receive an arbitrary text on an IPC socket. The module is defined with a single hook to be executed at the start to restore the latest status. 
[module/network]
type = custom/ipc
hook-0 = cat $XDG_RUNTIME_DIR/i3/network.txt 2> /dev/null
initial = 1
It can be updated with polybar-msg action "#network.send.XXXX". In the i3 companion, the @polybar() decorator takes the string returned by a function and pushes the update through the IPC socket. The i3 companion reacts to DBus signals to update the Bluetooth and network icons. The @on() decorator accepts a DBusSignal() object: 
@on(
    StartEvent,
    DBusSignal(
        path="/org/bluez",
        interface="org.freedesktop.DBus.Properties",
        member="PropertiesChanged",
        signature="sa sv as",
        onlyif=lambda args: (
            args[0] == "org.bluez.Device1"
            and "Connected" in args[1]
            or args[0] == "org.bluez.Adapter1"
            and "Powered" in args[1]
        ),
    ),
)
@retry(2)
@debounce(0.2)
@polybar("bluetooth")
async def bluetooth_status(i3, event, *args):
    """Update bluetooth status for Polybar."""
The middle of the bar is occupied by the date and a weather forecast. The latest also uses the IPC mechanism, but the source is a Python script triggered by a timer.
Date and weather in Polybar
Current date and weather forecast for the day in Polybar. The data is retrieved with the OpenWeather API.
I don t use the system tray integrated with Polybar. The embedded icons usually look horrible and they all behave differently. A few years back, Gnome has removed the system tray. Most of the problems are fixed by the DBus-based Status Notifier Item protocol also known as Application Indicators or Ayatana Indicators for GNOME. However, Polybar does not support this protocol. In the i3 companion, The implementation of Bluetooth and network icons, including displaying notifications on change, takes about 200 lines. I got to learn a bit about how DBus works and I get exactly the info I want.

picom: the compositor I like having slightly transparent backgrounds for terminals and to reduce the opacity of unfocused windows. This requires a compositor.1 picom is a lightweight compositor. It works well for me, but it may need some tweaking depending on your graphic card.2 Unlike the awesome window manager, i3 does not handle transparency, so the compositor needs to decide by itself the opacity of each window. Check my configuration for details.

systemd: the service manager I use systemd to start i3 and the various services around it. My xsession script only sets some environment variables and lets systemd handles everything else. Have a look at this article from Micha G ral for the rationale. Notably, each component can be easily restarted and their logs are not mangled inside the ~/.xsession-errors file.3 I am using a two-stage setup: i3.service depends on xsession.target to start services before i3: 
[Unit]
Description=X session
BindsTo=graphical-session.target
Wants=autorandr.service
Wants=dunst.socket
Wants=inputplug.service
Wants=picom.service
Wants=pulseaudio.socket
Wants=policykit-agent.service
Wants=redshift.service
Wants=spotify-clean.timer
Wants=ssh-agent.service
Wants=xiccd.service
Wants=xsettingsd.service
Wants=xss-lock.service
Then, i3 executes the second stage by invoking the i3-session.target: 
[Unit]
Description=i3 session
BindsTo=graphical-session.target
Wants=wallpaper.service
Wants=wallpaper.timer
Wants=polybar-weather.service
Wants=polybar-weather.timer
Wants=polybar.service
Wants=i3-companion.service
Wants=misc-x.service
Have a look on my configuration files for more details.

rofi: the application launcher Rofi is an application launcher. Its appearance can be customized through a CSS-like language and it comes with several themes. Have a look at my configuration for mine.
Rofi as an application launcher
Rofi as an application launcher
It can also act as a generic menu application. I have a script to control a media player and another one to select the wifi network. It is quite a flexible application.
Rofi as a wifi network selector
Rofi to select a wireless network

xss-lock and i3lock: the screen locker i3lock is a simple screen locker. xss-lock invokes it reliably on inactivity or before a system suspend. For inactivity, it uses the XScreenSaver events. The delay is configured using the xset s command. The locker can be invoked immediately with xset s activate. X11 applications know how to prevent the screen saver from running. I have also developed a small dimmer application that is executed 20 seconds before the locker to give me a chance to move the mouse if I am not away.4 Have a look at my configuration script.
Demonstration of xss-lock, xss-dimmer and i3lock with a 4 speedup.

The remaining components
  • autorandr is a tool to detect the connected display, match them against a set of profiles, and configure them with xrandr.
  • inputplug executes a script for each new mouse and keyboard plugged. This is quite useful to load the appropriate the keyboard map. See my configuration.
  • xsettingsd provides settings to X11 applications, not unlike xrdb but it notifies applications for changes. The main use is to configure the Gtk and DPI settings. See my article on HiDPI support on Linux with X11.
  • Redshift adjusts the color temperature of the screen according to the time of day.
  • maim is a utility to take screenshots. I use Prt Scn to trigger a screenshot of a window or a specific area and Mod+Prt Scn to capture the whole desktop to a file. Check the helper script for details.
  • I have a collection of wallpapers I rotate every hour. A script selects them using advanced machine learning algorithms and stitches them together on multi-screen setups. The selected wallpaper is reused by i3lock.
  1. Apart from the eye candy, a compositor also helps to get tear-free video playbacks.
  2. My configuration works with both Haswell (2014) and Whiskey Lake (2018) Intel GPUs. It also works with AMD GPU based on the Polaris chipset (2017).
  3. You cannot manage two different displays this way e.g. :0 and :1. In the first implementation, I did try to parametrize each service with the associated display, but this is useless: there is only one DBus user session and many services rely on it. For example, you cannot run two notification daemons.
  4. I have only discovered later that XSecureLock ships such a dimmer with a similar implementation. But mine has a cool countdown!

5 September 2021

Antoine Beaupr : Automating major Debian upgrades

It's major upgrade time again! The Debian project just published the Debian 11 "bullseye" release, and it's pretty awesome! This makes me realized that I have never written here about my peculiar upgrade process, and figured it was worth bringing that up to a wider audience. My upgrade process also has a notable changes section which includes major version changes (e.g. Inkscape 1.0!), new packages (e.g. podman!) and important behavior changes (e.g. driverless scanning and printing!). I'm particularly interested to hear about any significant change I might have missed. If you know of a cool new package that shipped with bullseye and that I forgot, do let me know! But that's for the cool new stuff. We need to talk about the problems with Debian major upgrades.

Background I have been maintaining detailed upgrade guides, on my wiki, starting with the jessie release, but I have actually written such guides for Koumbit.org as far back as Debian squeeze in 2011 (another worker wrote the older Debian lenny upgrade guide in 2009). Koumbit, since then, has kept maintaining those guides all the way to the latest bullseye upgrade, through 7 major releases! Over the years, those guides evolved from a quick "cheat-sheet" format copied from the release notes into a more or less "scripted" form that I currently use. Each guide has a procedure made of a few steps that can be basically copy-pasted to batch-upgrade a host (or multiple hosts in parallel) as quickly as possible. There is also the predict-os script which allows you to keep track of progress of the upgrades in a Puppet cluster.

Limitations of the official procedure In comparison with my procedure, the official upgrade guide is mostly designed to upgrade a single machine, typically a workstation, with a rather slow and exhaustive process. The PDF version of the upgrade guide is 14 pages long! This, obviously, does not work when you have tens or hundreds of machines to upgrade. Debian upgrades are notorious for being extremely reliable, but we have a lot of packages, and there are always corner cases where the upgrade will just fail because of a bug specific to your environment. Those will only be fixed after some back and forth in the community (and that's assuming users report those bugs, which is not always the case). There's no obvious way to deploy "hot fixes" in this context, at least not without fixing the package and publishing it on an unofficial Debian archive while the official ones catch up. This is slow and difficult. Or some packages require manual labor. Examples of this are the PostgreSQL or Ganeti packages which require you to upgrade your clusters by hand, while the old and new packages live side by side. Debian packages bring you far in the upgrade process, but sometimes not all the way. Which means every Debian install needs to be manually upgraded and inspected when a new release comes out. That's slow and error prone and we can do better.

How to automate major upgrades I have a proposal to automate this. It's been mostly dormant in the Debian wiki, for 5 years now. Fundamentally, this is a hard problem: Debian gets installed in so many different environments, from workstations to physical servers to virtual machines, embedded systems and so on, that it's extremely hard to come up with a "one size fits all" system. The (manual) procedure I'm using is mostly targeting servers, but I'm also using it on workstations. And I'll note that it's specific to my home setup: I have a different procedure at work, although it has a lot of common code. To automate this, I would factor out that common code with hooks where you could easily inject special code like "you need to upgrade ferm first", "you need an extra reboot here", or "this is how you finish the PostgreSQL upgrade". With Debian getting closer to a 2 year release cycle, with the previous release being supported basically only one year after the new stable comes out, I feel more and more strongly that this needs better automation. So I'm thinking that I should write a prototype for this. Ubuntu has do-release-upgrade that is too Ubuntu-specific to be reused. An attempt at collaborating on this has been mostly met with silence from Ubuntu's side as well. I'm thinking that using something like Fabric, Mitogen, or Transilience: anything that will allow me to write simple, portable Python code that can run transparently on a local machine (for single systems upgrades, possibly with a GUI frontend) to remote servers (for large clusters of servers, maybe with canaries and grouping using Cumin). I'll note that Koumbit started experimenting with Puppet Bolt in the bullseye upgrade process, but that feels too site-specific to be useful more broadly.

Trade-offs I am not sure where this stands in the XKCD time trade-off evaluation, because the table doesn't actually cover the time frequency of Debian release (which is basically "biennial") and the amount of time the upgrade would take across a cluster (which varies a lot, but that I estimate to be between one to 6 hours per machine). Assuming I have 80 machines to upgrade, that is 80 to 480 hours (between ~3 to 20 days) of work! It's unclear how much work such an automated system would shave off, however. Assuming things are an order of magnitude faster (say I upgrade 10 machines at a time), I would shave off between 3 and 18 days of work, which implies I might allow myself to spend a minimum of 5 days working on such a project.

The other option: never upgrade Before people mention those: I am aware of containers, Kubernetes, and other deployment mechanisms. Indeed, those may be a long-term solution, we currently can't afford to migrate everything over to containers right now: that is a huge migration and a total paradigm shift. At that point, whatever is left might not even be Debian in the first place. And besides, if you run Kubernetes, you still need to run some OS underneath and upgrade that, so that problem never completely disappears. Still, maybe that's the final answer: never upgrade. For some stateless machines like DNS replicas or load balancers, that might make a lot of sense as there's no or little data to carry to the new host. But this implies a seamless and fast provisioning process, and we don't have that either: at my work, installing a machine takes about as long as upgrading it, and that's after a significant amount of work automating that process, partly writing my own Debian installer with Fabric (!).

What is your process? I'm curious to hear what people think of those ideas. It strikes me as really odd that no one has really tackled that problem yet, considering how many clusters of Debian machines are out there. Surely people are upgrading those, and not following that slow step by step guide, right? I suspect everyone is doing the same thing: we all have our little copy-paste script we batch onto multiple machines, sometimes in parallel. That is what the Debian.org sysadmins are doing as well. There must be a better way. What is yours?

My upgrades so far So far, I have upgraded 2 out of my 3 home machines running buster -- others have been installed directly in bullseye -- with only my main, old, messy server left. Upgrades have been pretty painless so far (see another report, for example), much better than the previous buster upgrade. Obviously, for me personal use, automating this is pointless. Work-side, however, is another story: we have over 80 boxes to upgrade there and that will take a while. The last stretch to buster cycle took about two years to complete, so we might be done by the time the next release (12, "bookworm") is released, but that's actually a full year after "buster" becomes EOL, so it's actually too late... At least I fixed the installers so that new the machines we create all ship with bullseye, so we stopped accumulating new buster hosts...
Thanks to lelutin and pabs for reviewing a draft of this post.

Reproducible Builds: Reproducible Builds in August 2021

Welcome to the latest report from the Reproducible Builds project. In this post, we round up the important things that happened in the world of reproducible builds in August 2021. As always, if you are interested in contributing to the project, please visit the Contribute page on our website.
There were a large number of talks related to reproducible builds at DebConf21 this year, the 21st annual conference of the Debian Linux distribution (full schedule):
PackagingCon (@PackagingCon) is new conference for developers of package management software as well as their related communities and stakeholders. The virtual event, which is scheduled to take place on the 9th and 10th November 2021, has a mission is to bring different ecosystems together: from Python s pip to Rust s cargo to Julia s Pkg, from Debian apt over Nix to conda and mamba, and from vcpkg to Spack we hope to have many different approaches to package management at the conference . A number of people from reproducible builds community are planning on attending this new conference, and some may even present. Tickets start at $20 USD.
As reported in our May report, the president of the United States signed an executive order outlining policies aimed to improve the cybersecurity in the US. The executive order comes after a number of highly-publicised security problems such as a ransomware attack that affected an oil pipeline between Texas and New York and the SolarWinds hack that affected a large number of US federal agencies. As a followup this month, however, a detailed fact sheet was released announcing a number large-scale initiatives and that will undoubtedly be related to software supply chain security and, as a result, reproducible builds.
Lastly, We ran another productive meeting on IRC in August (original announcement) which ran for just short of two hours. A full set of notes from the meeting is available.

Software development kpcyrd announced an interesting new project this month called I probably didn t backdoor this which is an attempt to be:
a practical attempt at shipping a program and having reasonably solid evidence there s probably no backdoor. All source code is annotated and there are instructions explaining how to use reproducible builds to rebuild the artifacts distributed in this repository from source. The idea is shifting the burden of proof from you need to prove there s a backdoor to we need to prove there s probably no backdoor . This repository is less about code (we re going to try to keep code at a minimum actually) and instead contains technical writing that explains why these controls are effective and how to verify them. You are very welcome to adopt the techniques used here in your projects. ( )
As the project s README goes on the mention: the techniques used to rebuild the binary artifacts are only possible because the builds for this project are reproducible . This was also announced on our mailing list this month in a thread titled i-probably-didnt-backdoor-this: Reproducible Builds for upstreams. kpcyrd also wrote a detailed blog post about the problems surrounding Linux distributions (such as Alpine and Arch Linux) that distribute compiled Python bytecode in the form of .pyc files generated during the build process.

diffoscope diffoscope is our in-depth and content-aware diff utility. Not only can it locate and diagnose reproducibility issues, it can provide human-readable diffs from many kinds of binary formats. This month, Chris Lamb made a number of changes, including releasing version 180), version 181) and version 182) as well as the following changes:
  • New features:
    • Add support for extracting the signing block from Android APKs. [ ]
    • If we specify a suffix for a temporary file or directory within the code, ensure it starts with an underscore (ie. _ ) to make the generated filenames more human-readable. [ ]
    • Don t include short GCC lines that differ on a single prefix byte either. These are distracting, not very useful and are simply the strings(1) command s idea of the build ID, which is displayed elsewhere in the diff. [ ][ ]
    • Don t include specific .debug-like lines in the ELF-related output, as it is invariably a duplicate of the debug ID that exists better in the readelf(1) differences for this file. [ ]
  • Bug fixes:
    • Add a special case to SquashFS image extraction to not fail if we aren t the superuser. [ ]
    • Only use java -jar /path/to/apksigner.jar if we have an apksigner.jar as newer versions of apksigner in Debian use a shell wrapper script which will be rejected if passed directly to the JVM. [ ]
    • Reduce the maximum line length for calculating Wagner-Fischer, improving the speed of output generation a lot. [ ]
    • Don t require apksigner in order to compare .apk files using apktool. [ ]
    • Update calls (and tests) for the new version of odt2txt. [ ]
  • Output improvements:
    • Mention in the output if the apksigner tool is missing. [ ]
    • Profile diffoscope.diff.linediff and specialize. [ ][ ]
  • Logging improvements:
    • Format debug-level messages related to ELF sections using the diffoscope.utils.format_class. [ ]
    • Print the size of generated reports in the logs (if possible). [ ]
    • Include profiling information in --debug output if --profile is not set. [ ]
  • Codebase improvements:
    • Clarify a comment about the HUGE_TOOLS Python dictionary. [ ]
    • We can pass -f to apktool to avoid creating a strangely-named subdirectory. [ ]
    • Drop an unused File import. [ ]
    • Update the supported & minimum version of Black. [ ]
    • We don t use the logging variable in a specific place, so alias it to an underscore (ie. _ ) instead. [ ]
    • Update some various copyright years. [ ]
    • Clarify a comment. [ ]
  • Test improvements:
    • Update a test to check specific contents of SquashFS listings, otherwise it fails depending on the test systems user ID to username passwd(5) mapping. [ ]
    • Assign seen and expected values to local variables to improve contextual information in failed tests. [ ]
    • Don t print an orphan newline when the source code formatting test passes. [ ]

In addition Santiago Torres Arias added support for Squashfs version 4.5 [ ] and Felix C. Stegerman suggested a number of small improvements to the output of the new APK signing block [ ]. Lastly, Chris Lamb uploaded python-libarchive-c version 3.1-1 to Debian experimental for the new 3.x branch python-libarchive-c is used by diffoscope.

Distribution work In Debian, 68 reviews of packages were added, 33 were updated and 10 were removed this month, adding to our knowledge about identified issues. Two new issue types have been identified too: nondeterministic_ordering_in_todo_items_collected_by_doxygen and kodi_package_captures_build_path_in_source_filename_hash. kpcyrd published another monthly report on their work on reproducible builds within the Alpine and Arch Linux distributions, specifically mentioning rebuilderd, one of the components powering reproducible.archlinux.org. The report also touches on binary transparency, an important component for supply chain security. The @GuixHPC account on Twitter posted an infographic on what fraction of GNU Guix packages are bit-for-bit reproducible: Finally, Bernhard M. Wiedemann posted his monthly reproducible builds status report for openSUSE.

Upstream patches The Reproducible Builds project detects, dissects and attempts to fix as many currently-unreproducible packages as possible. We endeavour to send all of our patches upstream where appropriate. This month, we wrote a large number of such patches, including: Elsewhere, it was discovered that when supporting various new language features and APIs for Android apps, the resulting APK files that are generated now vary wildly from build to build (example diffoscope output). Happily, it appears that a patch has been committed to the relevant source tree. This was also discussed on our mailing list this month in a thread titled Android desugaring and reproducible builds started by Marcus Hoffmann.

Website and documentation There were quite a few changes to the Reproducible Builds website and documentation this month, including:
  • Felix C. Stegerman:
    • Update the website self-build process to not use the buster-backports suite now that Debian Bullseye is the stable release. [ ]
  • Holger Levsen:
    • Add a new page documenting various package rebuilder solutions. [ ]
    • Add some historical talks and slides from DebConf20. [ ][ ]
    • Various improvements to the history page. [ ][ ][ ]
    • Rename the Comparison protocol documentation category to Verification . [ ]
    • Update links to F-Droid documentation. [ ]
  • Ian Muchina:
    • Increase the font size of titles and de-emphasize event details on the talk page. [ ]
    • Rename the README file to README.md to improve the user experience when browsing the Git repository in a web browser. [ ]
  • Mattia Rizzolo:
    • Drop a position:fixed CSS statement that is negatively affecting with some width settings. [ ]
    • Fix the sizing of the elements inside the side navigation bar. [ ]
    • Show gold level sponsors and above in the sidebar. [ ]
    • Updated the documentation within reprotest to mention how ldconfig conflicts with the kernel variation. [ ]
  • Roland Clobus:
    • Added a ticket number for the issue with the live Cinnamon image and diffoscope. [ ]

Testing framework The Reproducible Builds project runs a testing framework at tests.reproducible-builds.org, to check packages and other artifacts for reproducibility. This month, the following changes were made:
  • Holger Levsen:
    • Debian-related changes:
      • Make a large number of changes to support the new Debian bookworm release, including adding it to the dashboard [ ], start scheduling tests [ ], adding suitable Apache redirects [ ] etc. [ ][ ][ ][ ][ ]
      • Make the first build use LANG=C.UTF-8 to match the official Debian build servers. [ ]
      • Only test Debian Live images once a week. [ ]
      • Upgrade all nodes to use Debian Bullseye [ ] [ ]
      • Update README documentation for the Debian Bullseye release. [ ]
    • Other changes:
      • Only include rsync output if the $DEBUG variable is enabled. [ ]
      • Don t try to install mock, a tool used to build Fedora packages some time ago. [ ]
      • Drop an unused function. [ ]
      • Various documentation improvements. [ ][ ]
      • Improve the node health check to detect zombie jobs. [ ]
  • Jessica Clarke (FreeBSD-related changes):
    • Update the location and branch name for the main FreeBSD Git repository. [ ]
    • Correctly ignore the source tarball when comparing build results. [ ]
    • Drop an outdated version number from the documentation. [ ]
  • Mattia Rizzolo:
    • Block F-Droid jobs from running whilst the setup is running. [ ]
    • Enable debugging for the rsync job related to Debian Live images. [ ]
    • Pass BUILD_TAG and BUILD_URL environment for the Debian Live jobs. [ ]
    • Refactor the master_wrapper script to use a Bash array for the parameters. [ ]
    • Prefer YAML s safe_load() function over the unsafe variant. [ ]
    • Use the correct variable in the Apache config to match possible existing files on disk. [ ]
    • Stop issuing HTTP 301 redirects for things that not actually permanent. [ ]
  • Roland Clobus (Debian live image generation):
    • Increase the diffoscope timeout from 120 to 240 minutes; the Cinnamon image should now be able to finish. [ ]
    • Use the new snapshot service. [ ]
    • Make a number of improvements to artifact handling, such as moving the artifacts to the Jenkins host [ ] and correctly cleaning them up at the right time. [ ][ ][ ]
    • Where possible, link to the Jenkins build URL that created the artifacts. [ ][ ]
    • Only allow only one job to run at the same time. [ ]
  • Vagrant Cascadian:
    • Temporarily disable armhf nodes for DebConf21. [ ][ ]

Lastly, if you are interested in contributing to the Reproducible Builds project, please visit the Contribute page on our website. You can get in touch with us via:

Fran ois Marier: Using implicit TLS in Postfix

In order to mitigate the NO STARTTLS vulnerabilities, I recently switched my local SMTP smarthosts from STARTTLS (port 587) to implicit TLS (port 465). Here are the key configuration parameters for Postfix (i.e. /etc/postfix/main.cf): 
relayhost = [smtp.kolabnow.com]:465
smtp_tls_wrappermode = yes
smtp_tls_security_level = secure
Note that this is for KolabNow, but the same works for GMail and Novus. The square brackets around the hostname tell Postfix not to look up the MX name using DNS and instead to use the SMTP server name as-is. Setting the smtp_tls_security_level parameter to secure ensures that the server is using a valid TLS certificate.

3 September 2021

Dirk Eddelbuettel: RcppSMC 0.2.4 on CRAN: Even More GSoC !!

A brand new release 0.2.4 of the RcppSMC package arrived on CRAN earlier today, with a dual delay for CRAN closing for a well-earned break, and then being overwhelmed when reopening. Other than that the processing was again versy smooth. RcppSMC provides Rcpp-based bindings to R for the Sequential Monte Carlo Template Classes (SMCTC) by Adam Johansen described in his JSS article. Sequential Monte Carlo is also referred to as Particle Filter in some contexts. The package started when I put some Rcpp bindings together based on Adam s paper and library. It grew when Adam and I supervised Leah South during the 2017 iteration of the Google Summer of Code. And now it grew again as we have Adam, Leah and myself looking over the shoulders of Ilya Zarubin who did very fine work during the 2021 iteration of the Google Summer of Code that just concluded! So we are now GSoC squared! This release is effectively all work by Ilya and summarized below.

Changes in RcppSMC version 0.2.4 (2021-09-01)
  • Multiple Sequential Monte Carlo extensions (Ilya Zarubin as part of Google Summer of Code 2021)
    • Provide informative user output (convergence diagnostics) for PMMH example #50 (Ilya in #50 and #52 addressing #25, bullet point 5)
    • Support for tracking of ancestral lines for base sampler class (Ilya in #56)
    • Support for conditional SMC via derived conditionalSampler class (Ilya in #60)
  • Add URL and BugReports to DESCRIPTION (Dirk in #53)

Courtesy of my CRANberries, there is a diffstat report for this release. More information is on the RcppSMC page. Issues and bugreports should go to the GitHub issue tracker. If you like this or other open-source work I do, you can now sponsor me at GitHub.

This post by Dirk Eddelbuettel originated on his Thinking inside the box blog. Please report excessive re-aggregation in third-party for-profit settings.

2 September 2021

Eddy Petri&#537;or: Stretch to Buster upgrade issues: "Grub error: symbol grub_is_lockdown not found", missing RTL8111/8168/8411 Ethernet driver and RTL8821CE Wireless adapter on Linux Kernel 5.10 (and 4.19)

I have been Debian Stretch running on my HP Pavilion 14-ce0000nq laptop since buying it back in April 2019, just before my presence at Oxidizeconf where I presented "How to Rust When Standards Are Defined in C".Debian Buster (aka Debian 10) was released about 4 months later and I've been postponing the upgrade as my free time isn't what it used to be. I also tend to wait for the first or even second update of the release to avoid any sharp edges.As this laptop has a Realtek 8821CE wireless card that wasn't officially supported in the Linux kernel, I had to use an out-of-tree hacked driver to have the wireless work on Stretch kernels such as 4.19, it didn't even got along with DKMS, so all compilations and installations of it, I did them manually. More reason to wait for a newer release that would contain a driver inside the official kernel.I was waiting for the inevitable and dreading the wireless issues, but since mid-august Bullseye became stable, turning Stretch into oldoldstable, I decided that I had to do the upgrade, at least to buster.The Grub error and the fix
Everything went quite smooth, except that after the reboot, the laptop failed to boot with this Grub error:

error: symbol grub_is_lockdown not found
I looked for a solution and it seemed everyone was stuck or the solution was unclear.There is even a bug report in Debian about this error, bug #984760.
Adding to the pile of confusion my own confused solution: I tried supergrubdisk2/rescatux, it didn't work for me, it might have been a combination of me using LVM and grub-efi-amd64. I also tried to boot in rescue mode the Buster first DVD (to avoid the need for network), I was able to enter the partition, mount the EFI partition, too, but since I didn't want to mess the setup even more or depend on an external USB stick, I didn't know where should I try to write the Grub EFI config - the root partition is on an NVME storage.When buying the laptop it had FreeDOS installed on it and some HP rescue app, which I did not wipe when installing Debian. I even forgot where or how was the EFI installed on the disk and EFI, even if it should be more reliable and simpler, I never got the hang of it.
In the end, I realized that I could via BIOS actually select manually which EFI executable should be booted into, so I was able to boot with some manual intervention during boot into the regular system.I tried regenerating the grub configuration, installing it and also tried restoring the default proper boot sequence (and I even installed refind in the system during my fumbling), but I think somewhere between grub-efi-amd64 reconfiguration and its reinstallation I managed to do the right thing, as the default boot screen is the Grub one now.Hints for anyone reading this in the hope to fix the same issue, hopefully it will make things better, not worse (see the text below):1) regenerate the grub config:
update-grub2
2) reinstall grub-efi-amd64 and make Debian the default
dpkg-reconfigure -plow grub-efi-amd64
When reinstalling grub-efi-amd64 onto the disk, I think the scariest questions were to these:

Force extra installation to the EFI removable media path?

Some EFI-based systems are buggy and do not handle new bootloaders correctly. If you force an extra installation of GRUB to the EFI removable media path, this should ensure that this system will boot Debian correctly despite such a problem. However, it may remove the ability to boot any other operating systems that also depend on this path. If so, you will need to make sure that GRUB is configured successfully to be able to boot any other OS installations correctly.

and
Update NVRAM variables to automatically boot into Debian?

GRUB can configure your platform's NVRAM variables so that it boots into Debian automatically when powered on. However, you may prefer to disable this behavior and avoid changes to your boot configuration. For example, if your NVRAM variables have been set up such that your system contacts a PXE server on every boot, this would preserve that behavior.

I think the first can be safely answered "No" if you don't plan on booting via a removable USB stick, while the second is the one that does the restoring.The second question is probably safe if you don't use PXE boot or other boot method, at least that's what I understand. But if you do, I suspect by installing refind, by playing with the multiple efi* named packages and tools, you can restore that, or it might be that your BIOS allows that directly.
I just did a walk through of these 2 steps again on my laptop and answered "No" to the removable media question as it leads to errors when the media was not inserted (in my case the internal SD card reader), and "Yes" to making Debian the default.It seems that for me this broke the FreeDOS and HP utilities boot entries from Grub, but I still can boot via the BIOS options and my goal was to have Debian boot correctly by default.
Fixing the missing RTL811/8168/8411 Ethernet card issue
As a side note for people with computers having Realtek RTL8111/8168/8411 Gigabit Ethernet Controller and upgrading to Buster or switching to a newer kernel, please note that you might end up having the unpleasant surprise even your Ethernet card to disappear because the r8169 driver is not loader by default.I had to add it to /etc/modules so is loaded by default:
eddy@aptonia:/ $ cat /etc/modules
# /etc/modules: kernel modules to load at boot time.
#
# This file contains the names of kernel modules that should be loaded
# at boot time, one per line. Lines beginning with "#" are ignored.
r8169

The 5.10 compatible driver for RTL8821CE wireless adapterAfter the upgrade to Buster, the oldstable version of the kernel, 4.19, the hacked version of the driver I've been using on Stretch on 4.9 kernels was no longer compatible - failed to compile due to missing symbols.The fix for me was to switch to the DKMS compatible driver from https://github.com/tomaspinho/rtl8821ce, as this seems to work for both 4.19 and 5.10 kernels (installed from backports).
I installed it via a modification of the manual install method only for the 4.19 and 5.10 kernels, leaving the legacy 4.9 kernels working with the hacked driver. You can do the same if instead of running the provided script, you do its steps manually and you install only for the kernel versions you want, instead of the default to install for all:I looked inside the dkms-install.sh script to do the required steps:Copy the driver, add it to the dkms set of known drivers:
DRV_NAME=rtl8821ce
DRV_VERSION=v5.5.2_34066.20200325

cp -r . /usr/src/$ DRV_NAME -$ DRV_VERSION

dkms add -m $ DRV_NAME -v $ DRV_VERSION
But you just build and install them only for the select kernel versions of your choice:
dkms build -m $ DRV_NAME -v $ DRV_VERSION -k 5.10.0-0.bpo.8-amd64
dkms install -m $ DRV_NAME -v $ DRV_VERSION -k 5.10.0-0.bpo.8-amd64
Or, without the variables:
dkms build rtl8821ce/v5.5.2_34066.20200325 -k 4.19.0-17-amd64
dkms install rtl8821ce/v5.5.2_34066.20200325 -k 4.19.0-17-amd64
dkms status should confirm everything is in place and I think you need to update grub2 again after this.
Please note this driver is no longer maintained and the 5.10 tree should support the RTL8821CE wireless card with the rtw88 driver from the kernel, but for me it did not. I'll probably try this at a later time, or after I upgrade to the current Debian stable, Bullseye.

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