probe_duration_seconds instance="example.net:5222",job="blackbox",module="xmpp_banner"  = 0.01
probe_duration_seconds instance="example.net:5269",job="blackbox",module="xmpp_banner"  = 0.01

Perl REGEX Problems courtesy of XKCD

label_replace(probe_duration_seconds module="xmpp_banner" , "port", "$1", "instance", ".*:(.*)")
probe_duration_seconds instance="example.net:5222",job="blackbox",module="xmpp_banner",port="5222" 	0.001
probe_duration_seconds instance="example.net:5269",job="blackbox",module="xmpp_banner",port="5269" 	0.002

1. Evaluate value, which is generally some sort of query such as probe_duration_seconds
2. Find the required source label src_label, in this example is instance, in this case the values are example.net:5222 and example.net:5269
3. Apply regular expression regex, for us its .*:(.*) That says skip everying before : then capture/store everything past : . The brackets mean copy what is after the colon and put it in match #1
4. Make a new label specified in dst_label, for us this is port
5. Whatever is in replacement goes into dst_label. For this example it is $1 which means match #1 in our regular expression in the label called port.

Grafana console showing the use of the label_replace function

Inter-canister calls The Internet Computer system provides inter-canister communication that follows the actor model: Inter-canister calls are implemented via two asynchronous messages, one to initiate the call, and one to return the response. Canisters process messages atomically (and roll back upon certain error conditions), but not complete calls. This makes programming with inter-canister calls error-prone. Possible common sources for bugs, vulnerabilities or simply unexpected behavior are:

• Reading global state before issuing an inter-canister call, and assuming it to still hold when the call comes back.
• Changing global state before issuing an inter-canister call, changing it again in the response handler, but assuming nothing else changes the state in between (reentrancy).
• Changing global state before issuing an inter-canister call, and not handling failures correctly, e.g. when the code handling the callback rolls backs.

If you find such pattern in your code, you should analyze if a malicious party can trigger them, and assess the severity that effect These issues apply to all canisters, and are not Motoko-specific.

Rollbacks Even in the absence of inter-canister calls the behavior of rollbacks can be surprising. In particular, rejecting (i.e. throw) does not rollback state changes done before, while trapping (e.g. Debug.trap, assert , out of cycle conditions) does. Therefore, one should check all public update call entry points for unwanted state changes or unwanted rollbacks. In particular, look for methods (or rather, messages, i.e. the code between commit points) where a state change is followed by a throw. This issues apply to all canisters, and are not Motoko-specific, although other CDKs may not turn exceptions into rejects (which don t roll back).

Talking to malicious canisters Talking to untrustworthy canisters can be risky, for the following (likely incomplete) reasons:

• The other canister can withhold a response. Although the bidirectional messaging paradigm of the Internet Computer was designed to guarantee a response eventually, the other party can busy-loop for as long as they are willing to pay for before responding. Worse, there are ways to deadlock a canister.
• The other canister can respond with invalidly encoded Candid. This will cause a Motoko-implemented canister to trap in the reply handler, with no easy way to recover. Other CDKs may give you better ways to handle invalid Candid, but even then you will have to worry about Candid cycle bombs that will cause your reply handler to trap.

Many canisters do not even do inter-canister calls, or only call other trustwothy canisters. For the others, the impact of this needs to be carefully assessed.

Canister upgrade: overview For most services it is crucial that canisters can be upgraded reliably. This can be broken down into the following aspects:

1. Can the canister be upgraded at all?
2. Will the canister upgrade retain all data?
3. Can the canister be upgraded promptly?
4. Is three a recovery plan for when upgrading is not possible?

Canister upgradeability A canister that traps, for whatever reason, in its canister_preupgrade system method is no longer upgradeable. This is a major risk. The canister_preupgrade method of a Motoko canister consists of the developer-written code in any system func preupgrade() block, followed by the system-generated code that serializes the content of any stable var into a binary format, and then copies that to stable memory. Since the Motoko-internal serialization code will first serialize into a scratch space in the main heap, and then copy that to stable memory, canisters with more than 2GB of live data will likely be unupgradeable. But this is unlikely the first limit: The system imposes an instruction limit on upgrading a canister (spanning both canister_preupgrade and canister_postupgrade). This limit is a subnet configuration value, and sepearate (and likely higher) than the normal per-message limit, and not easily determined. If the canister s live data becomes too large to be serialized within this limit, the canister becomes non-upgradeable. This risk cannot be eliminated completely, as long as Motoko and Stable Variables are used. It can be mitigated by appropriate load testing: Install a canister, fill it up with live data, and exercise the upgrade. If this succeeds with a live data set exceeding the expected amount of data by a margin, this risk is probably acceptable. Bonus points for adding functionality that will prevent the canister s live data to increase above a certain size. If this testing is to be done on a local replica, extra care needs to be taken to make sure the local replica actually performs instruction counting and has the same resource limits as the production subnet. An alternative mitigation is to avoid canister_pre_upgrade as much as possible. This means no use of stable var (or restricted to small, fixed-size configuration data). All other data could be

• mirrored off the canister (possibly off chain), and manually re-hydrated after an upgrade.
• stored in stable memory manually, during each update call, using the ExperimentalStableMemory API. While this matches what high-assurance Rust canisters (e.g. the Internet Identity) do, This requires manual binary encoding of the data, and is marked experimental, so I cannot recommend this at the moment.
• not put into a Motoko canister until Motoko has a scalable solution for stable variable (for example keeping them in stable memory permanently, with smart caching in main memory, and thus obliterating the need for pre-upgrade code.)

Data retention on upgrades Obviously, all live data ought to be retained during upgrades. Motoko automatically ensures this for stable var data. But often canisters want to work with their data in a different format (e.g. in objects that are not shared and thus cannot be put in stable vars, such as HashMap or Buffer objects), and thus may follow following idiom:

stable var fooStable =  ;
var foo = fooFromStable(fooStable);
system func preupgrade()   fooStable := fooToStable(foo);  )
system func postupgrade()   fooStable := (empty);  )

In this case, it is important to check that

• All non-stable global vars, or global lets with mutable values, have a stable companion.
• The assignments to foo and fooStable are not forgotten.
• The fooToStable and fooFromStable form bijections.

An example would be HashMaps stored as arrays via Iter.toArray( .entries()) and HashMap.fromIter( .vals()). It is worth pointiong out that a code view will only look at a single version of the code, but cannot check whether code changes will preserve data on upgrade. This can easily go wrong if the names and types of stable variables are changed in incompatible way. The upgrade may fail loudly in this cases, but in bad cases, the upgrade may even succeed, losing data along the way. This risk needs to be mitigated by thorough testing, and possibly backups (see below).

Prompt upgrades Motoko and Rust canisters cannot be safely upgraded when they are still waiting for responses to inter-canister calls (the callback would eventually reach the new instance, and because of infelicities of the IC s System API, could possibly call arbitrary internal functions). Therefore, the canister needs to be stopped before upgrading, and started again. If the inter-canister calls take a long time, this mean that upgrading may take a long time, which may be undesirable. Again, this risk is reduced if all calls are made to trustworthy canisters, and elevated when possibly untrustworthy canisters are called, directly or indirectly.

Backup and recovery Because of the above risk around upgrades it is advisable to have a disaster recovery strategy. This could involve off-chain backups of all relevant data, so that it is possible to reinstall (not upgrade) the canister and re-upload all data. Note that reinstall has the same issue as upgrade described above in prompt upgrades : It ought to be stopped first to be safe. Note that the instruction limit for messages, as well as the message size limit, limit the amount of data returned. If the canister needs to hold more data than that, the backup query method might have to return chunks or deltas, with all the extra complexity that entails, e.g. state changes between downloading chunks. If large data load testing is performed (as Irecommend anyways to test upgradeability), one can test whether the backup query method works within the resource limits.

Time is not strictly monotonic The timestamps for current time that the Internet Computer provides to its canisters is guaranteed to be monotonic, but not strictly monotonic. It can return the same values, even in the same messages, as long as they are processed in the same block. It should therefore not be used to detect happens-before relations. Instead of using and comparing time stamps to check whether Y has been performed after X happened last, introduce an explicit var y_done : Bool state, which is set to False by X and then to True by Y. When things become more complex, it will be easier to model that state via an enumeration with speaking tag names, and update this state machine along the way. Another solution to this problem is to introduce a var v : Nat counter that you bump in every update method, and after each await. Now v is your canister s state counter, and can be used like a timestamp in many ways. While we are talking about time: The system time (typically) changes across an await. So if you do let now = Time.now() and then await, the value in now may no longer be what you want.

Wrapping arithmetic The Nat64 data type, and the other fixed-width numeric types provide opt-in wrapping arithmetic (e.g. +%, fromIntWrap). Unless explicitly required by the current application, this should be avoided, as usually a too large or negatie value is a serious, unrecoverable logic error, and trapping is the best one can do.

Cycle balance drain attacks Because of the IC s canister pays model, all canisters are prone to DoS attacks by draining their cycle balance, and this risk needs to be taken into account. The most elementary mitigation strategy is to monitor the cycle balance of canisters and keep it far from the (configurable) freezing threshold. On the raw IC-level, further mitigation strategies are possible:

• If all update calls are authenticated, perform this authentication as quickly as possible, possibly before decoding the caller s argument. This way, a cycle drain attack by an unauthenticated attacker is less effective (but still possible).
• Additionally, implementing the canister_inspect_message system method allows the above checks to be performed before the message even is accepted by the Internet Computer. But it does not defend against inter-canister messages and is therefore not a complete solution.
• If an attack from an authenticated user (e.g. a stakeholder) is to be expected, the above methods are not effective, and an effective defense might require relatively involved additional program logic (e.g. per-caller statistics) to detect such an attack, and react (e.g. rate-limiting).
• Such defenses are pointless if there is only a single method where they do not apply (e.g. an unauthenticated user registration method). If the application is inherently attackable this way, it is not worth the bother to raise defenses for other methods.

Related: A justification why the Internet Identity does not use canister_inspect_message) A motoko-implemented canister currently cannot perform most of these defenses: Argument decoding happens unconditionally before any user code that may reject a message based on the caller, and canister_inspect_message is not supported. Furthermore, Candid decoding is not very cycle defensive, and one should assume that it is possible to construct Candid messages that require many instructions to decode, even for simple argument type signatures. The conclusion for the audited canisters is to rely on monitoring to keep the cycle blance up, even during an attack, if the expense can be born, and maybe pray for IC-level DoS protections to kick in.

Large data attacks Another DoS attack vector exists if public methods allow untrustworthy users to send data of unlimited size that is persisted in the canister memory. Because of the translation of async-await code into multiple message handlers, this applies not only to data that is obviously stored in global state, but also local data that is live across an await point. The effectiveness of such attacks is limited by the Internet Computer s message size limit, which is in the order of a few megabytes, but many of those also add up. The problem becomes much worse if a method has an argument type that allows a Candid space bomb: It is possible to encode very large vectors with all values null in Candid, so if any method has an argument of type [Null] or [?t], a small message will expand to a large value in the Motoko heap. Other types to watch out:

• Nat and Int: This is an unbounded natural number, and thus can be arbitrarily large. The Motoko representation will however not be much larger than the Candid encoding (so this does not qualify as a space bomb).

It is still advisable to check if the number is reasonable in size before storing it or doing an await. For example, when it denotes an index in an array, throw early if it exceeds the size of the array; if it denotes a token amount to transfer, check it against the available balance, if it denotes time, check it against reasonable bounds.

• Principal: A Principal is effectively a Blob. The Interface specification says that principals are at most 29 bytes in length, but the Motoko Candid decoder does not check that currently (fixed in the next version of Motoko). Until then, a Principal passed as an argument can be large (the principal in msg.caller is system-provided and thus safe). If you cannot wait for the fix to reach you, manually check the size of the princial (via Principal.toBlob) before doing the await.

Shadowing of msg or caller Don t use the same name for the message context of the enclosing actor and the methods of the canister: It is dangerous to write shared(msg) actor, because now msg is in scope across all public methods. As long as these also use public shared(msg) func , and thus shadow the outer msg, it is correct, but it if one accidentially omits or mis-types the msg, no compiler error would occur, but suddenly msg.caller would now be the original controller, likely defeating an important authorization step. Instead, write shared(init_msg) actor or shared( caller = controller ) actor to avoid using msg.

Conclusion If you write a serious canister, whether in Motoko or not, it is worth to go through the code and watch out for these patterns. Or better, have someone else review your code, as it may be hard to spot issues in your own code. Unfortunately, such a list is never complete, and there are surely more ways to screw up your code in addition to all the non-IC-specific ways in which code can be wrong. Still, things get done out there, so best of luck!

Welcome to the October 2021 report from the Reproducible Builds project!
This month Samanta Navarro posted to the oss-security security mailing on a novel category of exploit in the .tar archive format, where a single .tar file contains different contents depending on the tar utility being used. Naturally, this has consequences for reproducible builds as Samanta goes onto reply:

Arch Linux uses libarchive (bsdtar) in its build environment. The default tar program installed is GNU tar. It is possible to create a source distribution which leads to different files seen by the build environment than compared to a careful reviewer and other Linux distributions.

I have submitted bug reports and patches to some projects but eventually I had to conclude that the problem itself cannot be fixed by these implementations alone. The best choice for these tools would be to only allow archives which are fully compatible to standards but this in turn would render a lot of archives broken.

Reproducibility, repeatability and traceability of builds, drawing heavily on best-practices championed by the Reproducible Builds project.

I got a PR in my repository a few days ago leading back to a team trying to make it easier for packages to be reproducible from source.

Events and presentations

• PackagingCon is a conference for developers of package management software, their communities and other stakeholders. This virtual event, which will take place on the 9th and 10th November 2021, has a mission is to bring different ecosystems together . The schedule for the event is now available to view online.
• The Linux Foundation s OpenSSF group announced that the next OpenSSF quarterly town hall will take place on 15th November 2021. Registration is now open.

• Last month, Wolfgang Mauerer gave a presentation at the MiniDebConf 2021 Regensburg about the Civil Infrastructure Platform that covered many subjects including Reproducible Builds. PDF slides of the talk are available, as is a video recording.
• In addition, Trevor Rosen from SolarWinds presented at the Linux Foundation s Supply Chain Security Con last month on incorporating in-toto into their build system. in-toto a framework to secure the integrity of software supply chains. Trevor also discusses building everything twice to validate the first build la reproducible builds. (PDF slides)
• Lastly, Mattia Rizzolo posted an update on the next Reproducible Builds in-person event to our mailing list: currently we are thinking ahead to 2022 .

Community news On our mailing list this month:

• Jeremiah announced the release of version 1.4 of stage0-posix, part of a broader effort to provide an ultra-minimal bootstrap seed to increase trust in our software stack.
• Chris Lamb mentioned that Azure are offering free compute power for open source projects which might be useful for one of the many rebuilder projects .
• kpcyrd announced the release of rebuilderd v0.15.0, but also linked to a Twitter thread that contains intro on how rebuilderd works and a walk-through on how to write custom integrations.
• Fredrik Str mberg offered an update on the Sigsum project and some specific milestones within transparency logging efforts: after a year of design iterations we have not only designed a transparency log but also decided to turn it into a project of its own .

There were quite a few changes to the Reproducible Builds website and documentation this month as well, including Feng Chai updating some links on our publications page [ ] and marco updated our project metadata around the Bitcoin Core building guide [ ].
Lastly, we ran another productive meeting on IRC during October. A full set of notes from the meeting is available to view.

Distribution work Qubes was heavily featured in the latest edition of Linux Weekly News, and a significant section was dedicated to discussing reproducibility. For example, it was mentioned that the Qubes project has been working on incorporating reproducible builds into its continuous integration (CI) infrastructure . But the LWN article goes on to describe that:

The current goal is to be able to build the Qubes OS Debian templates solely from packages that can be built reproducibly. Templates in Qubes OS are VM images that can be used to start an application qube quickly based on the template. The qube will have read-only access to the root filesystem of the template, so that the same root filesystem can be shared with multiple application qubes. There are official templates for several variants of both Fedora and Debian, as well as community maintained templates for several other distributions.

You can view the whole article on LWN, and Fr d ric also published a lengthy summary about their work on reproducible builds in Qubes as well for those wishing to learn more.
In Debian this month, 133 reviews of Debian packages were added, 81 were updated and 24 were removed this month, adding to Debian s ever-growing knowledge about identified issues. A number of issues were categorised and added by Chris Lamb and Vagrant Cascadian too [ ][ ][ ]. In addition, work on alternative snapshot service has made progress by Fr d ric Pierret and Holger Levsen this month, including moving from the existing host (snapshot.notset.fr) to snapshot.reproducible-builds.org (more info) thanks to OSUOSL for the machine and hosting and Debian for the disks.
Finally, Bernhard M. Wiedemann posted his monthly reproducible builds status report.

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 the following changes, including preparing and uploading versions 186, 187, 188 and 189 to Debian

• New features:
  • Add support for Python Sphinx inventory files (usually named objects.inv on-disk). [ ]
  • Add support for comparing .pyc files. Thanks to Sergei Trofimovich for the inspiration. [ ]
  • Try some alternative suffixes (e.g. .py) to support distributions that strip or retain them. [ ][ ]
• Bug fixes:
  • Fix Python decompilation tests under Python 3.10+ [ ] and for Python 3.7 [ ].
  • Don t raise a traceback if we cannot unmarshal Python bytecode. This is in order to support Python 3.7 failing to load .pyc files generated with newer versions of Python. [ ]
  • Skip Python bytecode testing where we do not have an expected diff. [ ]
• Codebase improvements:
  • Use our file_version_is_lt utility instead of accepting both versions of uImage expected diff. [ ]
  • Split out a custom call to assert_diff for a .startswith equivalent. [ ]
  • Use skipif instead of manual conditionals in some tests. [ ]

In addition, Jelle van der Waa added external tool references for Arch Linux for ocamlobjinfo, openssl and ffmpeg [ ][ ][ ] and added Arch Linux as a Continuous Integration (CI) test target. [ ] and Vagrant Cascadian updated the testsuite to skip Python bytecode comparisons when file(1) is older than 5.39. [ ] as well as added external tool references for the Guix distribution for dumppdf and ppudump. [ ][ ]. Vagrant Cascadian also updated the diffoscope package in GNU Guix [ ][ ]. Lastly, Guangyuan Yang updated the FreeBSD package name on the website [ ], Mattia Rizzolo made a change to override a new Lintian warning due to the new test files [ ], Roland Clobus added support to detect and log if the GNU_BUILD_ID field in an ELF binary been modified [ ], Sandro J ckel updated a number of helpful links on the website [ ] and Sergei Trofimovich made the uImage test output support file() version 5.41 [ ].

reprotest reprotest is the Reproducible Build s project end-user tool to build same source code twice in widely differing environments, checking the binaries produced by the builds for any differences. This month, reprotest version 0.7.18 was uploaded to Debian unstable by Holger Levsen, which also included a change by Holger to clarify that Python 3.9 is used nowadays [ ], but it also included two changes by Vasyl Gello to implement realistic CPU architecture shuffling [ ] and to log the selected variations when the verbosity is configured at a sufficiently high level [ ]. Finally, Vagrant Cascadian updated reprotest to version 0.7.18 in GNU Guix.

Upstream patches The Reproducible Builds project detects, dissects and attempts to fix unreproducible packages. We try to send all of our patches upstream where appropriate. We authored a large number of such patches this month, including:

• Bernhard M. Wiedemann:
  • gtk4 (date-related issue)
  • ipxe (version upgrade)
  • libsoup2 (build failure in the future)
  • pari (parallelism-related issue)
• Chris Lamb:
  • #901307 filed against sphinx-gallery (re-opened with extensive updates).
  • #995809 filed against libinput.
  • #995865 filed against python-pipx.
  • #996200 filed against node-inquirer.
  • #996674 filed against libminidns-java.
  • #996834 filed against pytools.
  • #996881 filed against pikepdf.
  • #996948 filed against sphinx (forwarded upstream)
  • #996999 filed against fenics-basix.
  • #997000 filed against snakemake.
  • #997689 filed against smplayer.
  • #997949 filed against python-duniterpy.
  • #998104 filed against afnix.
  • #998059 filed against sphinx (forwarded upstream).
• Vagrant Cascadian:
  • #977684 filed against mahimahi (filed upstream).
  • #985187 filed against ffmpeg (forwarded upstream)
  • #995646 filed against abntex.
  • #995647 filed against cfi.
  • #995648 filed against cffi.
  • #995650 filed against chktex.
  • #995651 filed against fdutils.
  • #995652 filed against gnu-standards.
  • #995654 filed against malaga.
  • #995741 filed against latex-mk.
  • #995745 filed against kannel.
  • #995747 filed against xnee.
  • #995886, #995896, #995953 & #995954 filed against cxref.
  • #995960 filed against xnee.
  • #996184 filed against binutils-or1k-elf.
  • #996194 & #996572 filed against gcc-arm-none-eabi.
  • #996599 filed against xdmf.
  • #996679 filed against flightgear.
  • #997036 & #997037 filed against kvirc.

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:
    • Incorporate a fix from bremner into builtin-pho related to binary-NMUs. [ ]
    • Keep bullseye environments around longer, in an attempt to fix a Jenkins issue. [ ]
    • Improve the documentation of buildinfos.debian.net. [ ]
    • Improve documentation for the builtin-pho setup. [ ][ ]
  • OpenWrt-related changes:
    • Also use -j1 for better debugging. [ ]
    • Document that that Python 3.x is now used. [ ]
    • Enable further debugging for the toolchain build. [ ]
  • New snapshot.reproducible-builds.org service:
    • Actually add new node. [ ][ ]
    • Install xfsprogs on snapshot.reproducible-builds.org. [ ]
    • Create account for fpierret on new node. [ ]
    • Run node_health_check job on new node too. [ ]
• Mattia Rizzolo:
  • Debian-related changes:
    • Handle schroot errors when invoking diffoscope instead of masking them. [ ][ ]
    • Declare and define some variables separately to avoid masking the subshell return code. [ ]
    • Fix variable name. [ ]
    • Improve log reporting. [ ]
    • Execute apt-get update with the -q argument to get more decent logs. [ ]
    • Set the Debian HTTP mirror and proxy for snapshot.reproducible-builds.org. [ ]
    • Install the libarchive-tools package (instead of bsdtar) when updating Jenkins nodes. [ ]
  • Be stricter about errors when starting the node agent [ ] and don t overwrite NODE_NAME so that we can expect Jenkins to properly set for us [ ].
  • Explicitly warn if the NODE_NAME is not a fully-qualified domain name (FQDN). [ ]
  • Document whether a node runs in the future. [ ]
  • Disable postgresql_autodoc as it not available in bullseye. [ ]
  • Don t be so eager when deleting schroot internals, call to schroot -e to terminate the schroots instead. [ ]
  • Only consider schroot underlays for deletion that are over a month old. [ ][ ]
  • Only try to unmount /proc if it s actually mounted. [ ]
  • Move the db_backup task to its own Jenkins job. [ ]

Lastly, Vasyl Gello added usage information to the reproducible_build.sh script [ ].

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

• IRC: #reproducible-builds on irc.oftc.net.
• Twitter: @ReproBuilds
• Mailing list: rb-general@lists.reproducible-builds.org

$ ssh web04
$ rsync -e 'sh -c ">&2 echo $@" echo' -aLv /data/. web05:/data/.
web05 rsync --server -vlogDtpre.iLsfxCIvu . /data/.
rsync: connection unexpectedly closed (0 bytes received so far) [sender]
rsync error: error in rsync protocol data stream (code 12) at io.c(228) [sender=3.2.3]

$ ssh -L 127.0.0.1:5000:127.0.0.1:5000 web05
$ socat tcp-listen:5000,reuseaddr exec:"rsync --server -vlogDtpre.iLsfxCIvu . /data/."

$ ssh -R 127.0.0.1:5000:127.0.0.1:5000 web04
$ rsync -e 'sh -c "socat stdio tcp-connect:127.0.0.1:5000"' -aLv /data/. remote:/data/.
sending incremental file list
haproxy.debian.net/
haproxy.debian.net/dists/buster-backports-1.8/Contents-amd64.bz2
haproxy.debian.net/dists/buster-backports-1.8/Contents-i386.bz2
[ ]
media.luffy.cx/videos/2021-frnog34-jerikan/progressive.mp4
sent 921,719,453 bytes  received 26,939 bytes  7,229,383.47 bytes/sec
total size is 7,526,872,300  speedup is 8.17

How each process is connected together. Arrows labeled stdio are implemented as two pipes connecting the process to the left to the standard input and output of the process to the right. Don't be fooled by the apparent symmetry!

The options --server and --sender are used internally by rsync, and should never be typed by a user under normal circumstances. Some awareness of these options may be needed in certain scenarios, such as when setting up a login that can only run an rsync command. For instance, the support directory of the rsync distribution has an example script named rrsync (for restricted rsync) that can be used with a restricted ssh login.

Addendum I was hoping to get something similar with a one-liner. But this does not work!

$ socat \
>  exec:"ssh web04 rsync --server --sender -vlLogDtpre.iLsfxCIvu . /data/." \
>  exec:"ssh web05 rsync --server -vlogDtpre.iLsfxCIvu /data/. /data/." \
over-long vstring received (511 > 255)
over-long vstring received (511 > 255)
rsync error: requested action not supported (code 4) at compat.c(387) [sender=3.2.3]
rsync error: requested action not supported (code 4) at compat.c(387) [Receiver=3.2.3]
socat[878291] E waitpid(): child 878292 exited with status 4
socat[878291] E waitpid(): child 878293 exited with status 4

---

1. And SSH agent forwarding is dangerous. Don t use it if you can.

import smtplib

from email.mime.multipart import MIMEMultipart
from email.mime.image import MIMEImage

msg = MIMEMultipart('alternative')
msg['Subject'] = "subject"
msg['From'] = from_addr
msg['To'] = to_addr

part = MIMEImage(open('/path/to/image', 'rb').read())

s = smtplib.SMTP('localhost')
s.sendmail(from_addr, to_addr, msg.as_string())
s.quit()

import smtplib

from email.mime.multipart import MIMEMultipart
from email.mime.text import MIMEText
from email.mime.image import MIMEImage

msg = MIMEMultipart('alternative')
msg['Subject'] = "subject
msg['From'] = from_addr
msg['To'] = to_addr

text = MIMEText('<img src="cid:image1">', 'html')
msg.attach(text)

image = MIMEImage(open('/path/to/image', 'rb').read())

# Define the image's ID as referenced in the HTML body above
image.add_header('Content-ID', '<image1>')
msg.attach(image)

s = smtplib.SMTP('localhost')
s.sendmail(from_addr, to_addr, msg.as_string())
s.quit()

import smtplib

from email.mime.multipart import MIMEMultipart
from email.mime.image import MIMEImage

msg = MIMEMultipart('alternative')
msg['Subject'] = "subject"
msg['From'] = from_addr
msg['To'] = to_addr

part = MIMEImage(open('/path/to/image', 'rb').read())

s = smtplib.SMTP('localhost')
s.sendmail(from_addr, to_addr, msg.as_string())
s.quit()

import smtplib

from email.mime.multipart import MIMEMultipart
from email.mime.text import MIMEText
from email.mime.image import MIMEImage

msg = MIMEMultipart('alternative')
msg['Subject'] = "subject
msg['From'] = from_addr
msg['To'] = to_addr

text = MIMEText('<img src="cid:image1">', 'html')
msg.attach(text)

image = MIMEImage(open('/path/to/image', 'rb').read())

# Define the image's ID as referenced in the HTML body above
image.add_header('Content-ID', '<image1>')
msg.attach(image)

s = smtplib.SMTP('localhost')
s.sendmail(from_addr, to_addr, msg.as_string())
s.quit()

Uniform representation The Motoko programming language, designed by Andreas Rossberg and implemented by a pretty cool team at DFINITY is a high-level language with strict semantics and a strong, structural, equi-recursive type system that compiles down to WebAssembly. Because the type system supports polymorphism, it represents all values uniformly. Simplified for the purpose of this blog post, they are always pointers into a heap object where the first word of the heap object, the heap tag, contains information about the value:

 
  tag    
 

The tag is something like array, int64, blob, variant, record, , and it has two purposes:

• The garbage collector uses it to understand what kind of object it is looking at, so that it can move it around and follow pointers therein. Variable size objects such as arrays include the object size in a subsequent word of the heap object.
• Some types have values that may have different shapes on the heap. For example, the ropes used in our text representation can either be a plain blob, or a concatenation node of two blobs. For these types, the tag of the heap object is inspected.

The optional type, naively The optional type (?t) is another example of such a type: Its values can either be null, or ?v for some value v of type t, and the primitive operations on this type are the two introduction forms, an analysis function, and a projection for non-null values:

null : () -> ?t
some : t -> ?t
is_some : ?t -> bool
project : ?t -> t     // must only be used if is_some holds

It is natural to use the heap tag to distinguish the two kind of values:

• The null value is a simple one-word heap object with just a tag that says that this is null:

   
    null  
   

• The other values are represented by a two-word object: The tag some, indicating that it is a ?v, and then the payload, which is the pointer that represents the value v:

   
    some   payload  
   

With this, the four operations can be implemented as follows:

def null():
  ptr <- alloc(1)
  ptr[0] = NULL_TAG
  return ptr
def some(v):
  ptr <- alloc(2)
  ptr[0] = SOME_TAG
  ptr[1] = v
  return ptr
def is_some(p):
  return p[0] == SOME_TAG
def project(p):
  return p[1]

The problem with this implementation is that null() and some(v) both allocate memory. This is bad if they are used very often, and very liberally, and this is the case in Motoko: For example the iterators used for the for (x in e) construct have type

type Iter<T> =   next : () -> ?T  

and would unavoidably allocate a few words on each iteration. Can we avoid this?

Static values It is quite simple to avoid this for for null: Just statically create a single null value and use it every time:

static_null = [NULL_TAG]
def null():
  return static_null

This way, at least null() doesn t allocate. But we gain more: Now every null value is represented by the same pointer, and since the pointer points to static memory, it does not change even with a moving garbage collector, so we can speed up is_some:

def is_some(p):
  return p != static_null

This is not a very surprising change so far, and most compilers out there can and will do at least the static allocation of such singleton constructors. For example, in Haskell, there is only a single empty list ([]) and a single Nothing value in your program, as you can see in my videos exploring the Haskell heap. But can we get rid of the allocation in some(v) too?

Unwrapped optional values If we don t want to allocate in some(v), what can we do? How about simply

def some(v):
  return v

That does not allocate! But it is also broken. At type ??Int, the values null, ?null and ??null are distinct values, but here this breaks. Or, more formally, the following laws should hold for our four primitive operations:

1. is_some(null()) = false
2. v. is_some(some(v)) = true
3. p. project(some(p)) = p

But with the new definition of some, we d get is_some(some(null())) = false. Not good! But note that we only have a problem if we are wrapping a value that is null or some(v). So maybe take the shortcut only then, and write the following:

def some(v):
  if v == static_null   v[0] == SOME_TAG:
    ptr <- alloc(2)
    ptr[0] = SOME_TAG
    ptr[1] = v
    return ptr
  else:
    return v

The definition of is_some can stay as it is: It is still the case that all null values are represented by static_null. But the some values are now no longer all of the same shape, so we have to change project():

def project(p):
  if p[0] == SOME_TAG:
    return p[1]
  else:
    return p

Now things fall into place: A value ?v can, in many cases, be represented the same way as v, and no allocation is needed. Only when v is null or ?null or ??null or ???null etc. we need to use the some heap object, and thus have to allocate. In fact, it doesn t cost much to avoid allocation even for ?null:

static_some_null = [SOME_TAG, static_null]
def some(v):
  if v == static_null:
    return static_some_null
  else if v[0] == SOME_TAG:
    ptr <- alloc(2)
    ptr[0] = SOME_TAG
    ptr[1] = v
    return ptr
  else:
    return v

So unless one nests the ? type two levels deep, there is no allocation whatsoever, and the only cost is a bit more branching in some and project. That wasn t hard, but quite rewarding, as one can now use idioms like the iterator shown above with greater ease.

Examples The following tables shows the representation of various values before and after. Here [ ] is a pointed-to dynamically allocated heap object, a statically allocated heap object, N = NULL_TAG and S = SOME_TAG.

type	value	before	after
Null	null	N	N
?Int	null	N	N
?Int	?23	[S,23]	23
??Int	null	N	N
??Int	?null	[S, N ]	S, N
??Int	??23	[S,[S,23]]	23
???Int	null	N	N
???Int	?null	[S, N ]	S, N
???Int	??null	[S,[S, N ]]	[S, S, N ]
???Int	???23	[S,[S,[S,23]]]	23

Concluding remarks

• If you know what parametric polymorphism is, and wonder how this encoding can work in a language that has that, note that this representation is on the low-level of the untyped run-time value representation: We don t need to know the type of v in some(v), merely its heap representation.
• The uniform representation in Motoko is a bit more involved: The pointers are tagged (by subtracting 1) and some scalar values are represented directly in place (shifted left by 1 bit). But this is luckily orthogonal to what I showed here.
• Could Haskell do this for its Maybe type? Not so easily:
  • The Maybe type is not built-in, but rather a standard library-defined algebraic data type. But the compiler could feasible detect that this is option-like?
  • Haskell is lazy, so at runtime, the type Maybe could be Nothing, or Just v, or, and this is crucial, a yet to be evaluated expression, also called a thunk. And one definitely needs to distinguish between a thunk t :: Maybe a that may evaluate to Nothing, and a value Just t :: Maybe a that definitely is Just, but contains a value, which may be a thunk.
  Something like this may work for a strict Maybe type or unlifted sums like (# (# #) a #), but may clash with other ticks in GHC, such as pointer tagging.
• As I said above, I don t expect this to be novel, and I am happy to add references to prior art here.
• Given that a heap object with tag SOME_TAG now always encodes a tower ? null for n>0, one could try to optimize that even more by just storing the n:

   
    some    n   
   

  But that seems unadvisable: It is only a win if you have deep towers, which is probably rare. Worse, now the project function would have to return such a heap object with n decremented, so now projection might have to allocate, which goes against the cost model expected by the programmer.
• If you rather want to see code than blog posts, feel free to check out Motoko PR #2115.
• Does this kind of stuff excite you? Motoko is open source, so your contributions may be welcome!

Changes in version 0.1.0 (2021-10-30)

• Code reorganized to have minimal (documented) changes relative to upstream, essentially just removing unused headers, and pragma
• Added example for full calendaring to README.md

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

Changes in version 0.0.15 (2021-10-26)

• Corrected scope of 'extern "C"' declaration to the actually C-callable function (noticed by clang++, change requested by CRAN)

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

(defhost lxc1.silentflame.com ()
  (os:debian-stable "bullseye" :amd64)
  (basic-props)
  (apt:installed "systemd" "netcat")
  (apache:https-vhost ...))
(defhost lxctest.laptop.silentflame.com ()
  (os:debian-stable "bullseye" :amd64)
  (apt:proxy "http://192.168.122.1:3142")
  (basic-props)
  (apt:installed "linux-image-amd64" "lxc")
  (lxc:usernet-usable-by "spwhitton" "lxcbr0")
  (lxc:user-containers-autostart "spwhitton")
  (lxc:user-container-for '(:additional-lines
                            ("lxc.net.0.type = veth"
                             "lxc.net.0.flags = up"
                             "lxc.net.0.link = lxcbr0"
                             ...))
                          "spwhitton"
                          lxc1.silentflame.com))
(defhost laptop.silentflame.com ()
  ...
  (libvirt:kvm-boots-chroot-for '(:always-deploys t)
                                lxctest.laptop.silentflame.com))

(defun route-athenet-container-veth (host)
  (let ((user (getenv "USERV_USER"))
        (peer (getenv "USERV_U_PEER"))
        (ip (car (uiop:command-line-arguments))))
    (unless (string-prefix-p (format nil "veth~D_" (getenv "USERV_UID")) peer)
      (error "~A does not belong to requester." peer))
    (unless (member (cons user ip) (get-hostattrs 'veth-ips host) :test #'equal)
      (error "~A does not have permission to route ~A." user ip))
    (flet ((r (&rest args)
             ;; Explicitly passing nil means UIOP will not invoke a shell.
             (run-program args :force-shell nil)))
      (eswitch ((getenv "USERV_U_HOOK_TYPE") :test #'string=)
        ("up"
         (apply #'r
                "sysctl" "-w"
                "net.ipv6.conf.all.forwarding=1"
                ...)
         (r "ip" "addr" "flush" "dev" peer "scope" "link")
         (r "ip" "-6" "addr" "add" "fe80::1/64" "dev" peer)
         (r "ip" "-6" "route" "add" (strcat ip "/128") "dev" peer)
         ...)
        ("down"
         ...
         (r "ip" "-6" "route" "del" (strcat ip "/128") "dev" peer))))))

(image-dumped
 "/usr/lib/userv/route-athenet-container-veth"
  (route-athenet-container-veth ,(intern (string-upcase (get-hostname)))))

What is Neo-Colonialism? The term "neo-colonialism" was coined by Kwame Nkrumah, first president of Ghana. In Neo-Colonialism, the Last Stage of Imperialism (1965), he wrote:

In place of colonialism, as the main instrument of imperialism, we have today neo-colonialism ... [which] like colonialism, is an attempt to export the social conflicts of the capitalist countries. ... The result of neo-colonialism is that foreign capital is used for the exploitation rather than for the development of the less developed parts of the world. Investment, under neo-colonialism, increases, rather than decreases, the gap between the rich and the poor countries of the world.

So basically, if colonialism is Europeans bringing genocide, war, and its religion to the Africa, Asia, and the Americas, neo-colonialism is the Americans (note the "n") bringing capitalism to the world. Before we see how this applies to the Internet, we must therefore make a detour into US history. This matters, because anyone would be hard-pressed to decouple neo-colonialism from the empire under which it evolves, and here we can only name the United States of America.

US Declaration of Independence Let's start with the United States declaration of independence (1776). Many Americans may roll their eyes at this, possibly because that declaration is not actually part of the US constitution and therefore may have questionable legal standing. Still, it was obviously a driving philosophical force in the founding of the nation. As its author, Thomas Jefferson, stated:

it was intended to be an expression of the American mind, and to give to that expression the proper tone and spirit called for by the occasion

In that aging document, we find the following pearl:

We hold these truths to be self-evident, that all men are created equal, that they are endowed by their Creator with certain unalienable Rights, that among these are Life, Liberty and the pursuit of Happiness.

As a founding document, the Declaration still has an impact in the sense that the above quote has been called an:

"immortal declaration", and "perhaps [the] single phrase" of the American Revolutionary period with the greatest "continuing importance." (Wikipedia)

Let's read that "immortal declaration" again: "all men are created equal". "Men", in that context, is limited to a certain number of people, namely "property-owning or tax-paying white males, or about 6% of the population". Back when this was written, women didn't have the right to vote, and slavery was legal. Jefferson himself owned hundreds of slaves. The declaration was aimed at the King and was a list of grievances. A concern of the colonists was that the King:

has excited domestic insurrections amongst us, and has endeavoured to bring on the inhabitants of our frontiers, the merciless Indian Savages whose known rule of warfare, is an undistinguished destruction of all ages, sexes and conditions.

This is a clear mark of the frontier myth which paved the way for the US to exterminate and colonize the territory some now call the United States of America. The declaration of independence is obviously a colonial document, having being written by colonists. None of this is particularly surprising, historically, but I figured it serves as a good reminder of where the Internet is coming from, since it was born in the US.

A Declaration of the Independence of Cyberspace Two hundred and twenty years later, in 1996, John Perry Barlow wrote a declaration of independence of cyberspace. At this point, (almost) everyone has a right to vote (including women), slavery was abolished (although some argue it still exists in the form of the prison system); the US has made tremendous progress. Surely this text will have aged better than the previous declaration it is obviously derived from. Let's see how it reads today and how it maps to how the Internet is actually built now.

Borders of Independence One of the key ideas that Barlow brings up is that "cyberspace does not lie within your borders". In that sense, cyberspace is the final frontier: having failed to colonize the moon, Americans turn inwards, deeper into technology, but still in the frontier ideology. And indeed, Barlow is one of the co-founder of the Electronic Frontier Foundation (the beloved EFF), founded six years prior. But there are other problems with this idea. As Wikipedia quotes:

The declaration has been criticized for internal inconsistencies.[9] The declaration's assertion that 'cyberspace' is a place removed from the physical world has also been challenged by people who point to the fact that the Internet is always linked to its underlying geography.[10]

And indeed, the Internet is definitely a physical object. First controlled and severely restricted by "telcos" like AT&T, it was somewhat "liberated" from that monopoly in 1982 when an anti-trust lawsuit broke up the monopoly, a key historical event that, one could argue, made the Internet possible. (From there on, "backbone" providers could start competing and emerge, and eventually coalesce into new monopolies: Google has a monopoly on search and advertisement, Facebook on communications for a few generations, Amazon on storage and computing, Microsoft on hardware, etc. Even AT&T is now pretty much as consolidated as it was before.) The point is: all those companies have gigantic data centers and intercontinental cables. And those are definitely prioritizing the western world, the heart of the empire. Take for example Google's latest 3,900 mile undersea cable: it does not connect Argentina to South Africa or New Zealand, it connects the US to UK and Spain. Hardly a revolutionary prospect.

Private Internet But back to the Declaration:

Do not think that you can build it, as though it were a public construction project. You cannot. It is an act of nature and it grows itself through our collective actions.

In Barlow's mind, the "public" is bad, and private is good, natural. Or, in other words, a "public construction project" is unnatural. And indeed, the modern "nature" of development is private: most of the Internet is now privately owned and operated. I must admit that, as an anarchist, I loved that sentence when I read it. I was rooting for "us", the underdogs, the revolutionaries. And, in a way, I still do: I am on the board of Koumbit and work for a non-profit that has pivoted towards censorship and surveillance evasion. Yet I cannot help but think that, as a whole, we have failed to establish that independence and put too much trust in private companies. It is obvious in retrospect, but it was not, 30 years ago. Now, the infrastructure of the Internet has zero accountability to traditional political entities supposedly representing the people, or even its users. The situation is actually worse than when the US was founded (e.g. "6% of the population can vote"), because the owners of the tech giants are only a handful of people who can override any decision. There's only one Amazon CEO, he's called Jeff Bezos, and he has total control. (Update: Bezos actually ceded the CEO role to Andy Jassy, AWS and Amazon music founder, while remaining executive chairman. I would argue that, as the founder and the richest man on earth, he still has strong control over Amazon.)

Social Contract Here's another claim of the Declaration:

We are forming our own Social Contract.

I remember the early days, back when "netiquette" was a word, it did feel we had some sort of a contract. Not written in standards of course -- or barely (see RFC1855) -- but as a tacit agreement. How wrong we were. One just needs to look at Facebook to see how problematic that idea is on a global network. Facebook is the quintessential "hacker" ideology put in practice. Mark Zuckerberg explicitly refused to be "arbiter of truth" which implicitly means he will let lies take over its platforms. He also sees Facebook as place where everyone is equal, something that echoes the Declaration:

We are creating a world that all may enter without privilege or prejudice accorded by race, economic power, military force, or station of birth.

(We note, in passing, the omission of gender in that list, also mirroring the infamous "All men are created equal" claim of the US declaration.) As the Wall Street Journal's (WSJ) Facebook files later shown, both of those "contracts" have serious limitations inside Facebook. There are VIPs who systematically bypass moderation systems including fascists and rapists. Drug cartels and human traffickers thrive on the platform. Even when Zuckerberg himself tried to tame the platform -- to get people vaccinated or to make it healthier -- he failed: "vaxxer" conspiracies multiplied and Facebook got angrier. This is because the "social contract" behind Facebook and those large companies is a lie: their concern is profit and that means advertising, "engagement" with the platform, which causes increased anxiety and depression in teens, for example. Facebook's response to this is that they are working really hard on moderation. But the truth is that even that system is severely skewed. The WSJ showed that Facebook has translators for only 50 languages. It's a surprisingly hard to count human languages but estimates range the number of distinct languages between 2500 and 7000. So while 50 languages seems big at first, it's actually a tiny fraction of the human population using Facebook. Taking the first 50 of the Wikipedia list of languages by native speakers we omit languages like Dutch (52), Greek (74), and Hungarian (78), and that's just a few random nations picks from Europe. As an example, Facebook has trouble moderating even a major language like Arabic. It censored content from legitimate Arab news sources when they mentioned the word al-Aqsa because Facebook associates it with the al-Aqsa Martyrs' Brigades when they were talking about the Al-Aqsa Mosque... This bias against Arabs also shows how Facebook reproduces the American colonizer politics. The WSJ also pointed out that Facebook spends only 13% of its moderation efforts outside of the US, even if that represents 90% of its users. Facebook spends three more times moderating on "brand safety", which shows its priority is not the safety of its users, but of the advertisers.

Military Internet Sergey Brin and Larry Page are the Lewis and Clark of our generation. Just like the latter were sent by Jefferson (the same) to declare sovereignty over the entire US west coast, Google declared sovereignty over all human knowledge, with its mission statement "to organize the world's information and make it universally accessible and useful". (It should be noted that Page somewhat questioned that mission but only because it was not ambitious enough, Google having "outgrown" it.) The Lewis and Clark expedition, just like Google, had a scientific pretext, because that is what you do to colonize a world, presumably. Yet both men were military and had to receive scientific training before they left. The Corps of Discovery was made up of a few dozen enlisted men and a dozen civilians, including York an African American slave owned by Clark and sold after the expedition, with his final fate lost in history. And just like Lewis and Clark, Google has a strong military component. For example, Google Earth was not originally built at Google but is the acquisition of a company called Keyhole which had ties with the CIA. Those ties were brought inside Google during the acquisition. Google's increasing investment inside the military-industrial complex eventually led Google to workers organizing a revolt although it is currently unclear to me how much Google is involved in the military apparatus. Other companies, obviously, do not have such reserve, with Microsoft, Amazon, and plenty of others happily bidding on military contracts all the time.

Spreading the Internet I am obviously not the first to identify colonial structures in the Internet. In an article titled The Internet as an Extension of Colonialism, Heather McDonald correctly identifies fundamental problems with the "development" of new "markets" of Internet "consumers", primarily arguing that it creates a digital divide which creates a "lack of agency and individual freedom":

Many African people have gained access to these technologies but not the freedom to develop content such as web pages or social media platforms in their own way. Digital natives have much more power and therefore use this to create their own space with their own norms, shaping their online world according to their own outlook.

But the digital divide is certainly not the worst problem we have to deal with on the Internet today. Going back to the Declaration, we originally believed we were creating an entirely new world:

This governance will arise according to the conditions of our world, not yours. Our world is different.

How I dearly wished that was true. Unfortunately, the Internet is not that different from the offline world. Or, to be more accurate, the values we have embedded in the Internet, particularly of free speech absolutism, sexism, corporatism, and exploitation, are now exploding outside of the Internet, into the "real" world. The Internet was built with free software which, fundamentally, was based on quasi-volunteer labour of an elite force of white men with obviously too much time on their hands (and also: no children). The mythical writing of GCC and Emacs by Richard Stallman is a good example of this, but the entirety of the Internet now seems to be running on random bits and pieces built by hit-and-run programmers working on their copious free time. Whenever any of those fails, it can compromise or bring down entire systems. (Heck, I wrote this article on my day off...) This model of what is fundamentally "cheap labour" is spreading out from the Internet. Delivery workers are being exploited to the bone by apps like Uber -- although it should be noted that workers organise and fight back. Amazon workers are similarly exploited beyond belief, forbidden to take breaks until they pee in bottles, with ambulances nearby to carry out the bodies. During peak of the pandemic, workers were being dangerously exposed to the virus in warehouses. All this while Amazon is basically taking over the entire economy. The Declaration culminates with this prophecy:

We will spread ourselves across the Planet so that no one can arrest our thoughts.

This prediction, which first felt revolutionary, is now chilling.

Colonial Internet The Internet is, if not neo-colonial, plain colonial. The US colonies had cotton fields and slaves, we have disposable cell phones and Foxconn workers. Canada has its cultural genocide, Facebook has his own genocides in Ethiopia, Myanmar, and mob violence in India. Apple is at least implicitly accepting the Uyghur genocide. And just like the slaves of the colony, those atrocities are what makes the empire run. The Declaration actually ends like this, a quote which I have in my fortune cookies file:

We will create a civilization of the Mind in Cyberspace. May it be more humane and fair than the world your governments have made before.

That is still inspiring to me. But if we want to make "cyberspace" more humane, we need to decolonize it. Work on cyberpeace instead of cyberwar. Establish clear code of conduct, discuss ethics, and question your own privileges, biases, and culture. For me the first step in decolonizing my own mind is writing this article. Breaking up tech monopolies might be an important step, but it won't be enough: we have to do a culture shift as well, and that's the hard part.

Appendix: an apology to Barlow I kind of feel bad going through Barlow's declaration like this, point by point. It is somewhat unfair, especially since Barlow passed away a few years ago and cannot mount a response (even humbly assuming that he might read this). But then again, he himself recognized he was a bit too "optimistic" in 2009, saying: "we all get older and smarter":

I'm an optimist. In order to be libertarian, you have to be an optimist. You have to have a benign view of human nature, to believe that human beings left to their own devices are basically good. But I'm not so sure about human institutions, and I think the real point of argument here is whether or not large corporations are human institutions or some other entity we need to be thinking about curtailing. Most libertarians are worried about government but not worried about business. I think we need to be worrying about business in exactly the same way we are worrying about government.

And, in a sense, it was a little naive to expect Barlow to not be a colonist. Barlow is, among many things, a cattle rancher who grew up on a colonial ranch in Wyoming. The ranch was founded in 1907 by his great uncle, 17 years after the state joined the Union, and only a generation or two after the Powder River War (1866-1868) and Black Hills War (1876-1877) during which the US took over lands occupied by Lakota, Cheyenne, Arapaho, and other native American nations, in some of the last major First Nations Wars.

Appendix: further reading There is another article that almost has the same title as this one: Facebook and the New Colonialism. (Interestingly, the <title> tag on the article is actually "Facebook the Colonial Empire" which I also find appropriate.) The article is worth reading in full, but I loved this quote so much that I couldn't resist reproducing it here:

Representations of colonialism have long been present in digital landscapes. ( Even Super Mario Brothers, the video game designer Steven Fox told me last year. You run through the landscape, stomp on everything, and raise your flag at the end. ) But web-based colonialism is not an abstraction. The online forces that shape a new kind of imperialism go beyond Facebook.

It goes on:

Consider, for example, digitization projects that focus primarily on English-language literature. If the web is meant to be humanity s new Library of Alexandria, a living repository for all of humanity s knowledge, this is a problem. So is the fact that the vast majority of Wikipedia pages are about a relatively tiny square of the planet. For instance, 14 percent of the world s population lives in Africa, but less than 3 percent of the world s geotagged Wikipedia articles originate there, according to a 2014 Oxford Internet Institute report.

And they introduce another definition of Neo-colonialism, while warning about abusing the word like I am sort of doing here:

I m loath to toss around words like colonialism but it s hard to ignore the family resemblances and recognizable DNA, to wit, said Deepika Bahri, an English professor at Emory University who focuses on postcolonial studies. In an email, Bahri summed up those similarities in list form:

1. ride in like the savior
2. bandy about words like equality, democracy, basic rights
3. mask the long-term profit motive (see 2 above)
4. justify the logic of partial dissemination as better than nothing
5. partner with local elites and vested interests
6. accuse the critics of ingratitude

In the end, she told me, if it isn t a duck, it shouldn t quack like a duck.

Another good read is the classic Code and other laws of cyberspace (1999, free PDF) which is also critical of Barlow's Declaration. In "Code is law", Lawrence Lessig argues that:

computer code (or "West Coast Code", referring to Silicon Valley) regulates conduct in much the same way that legal code (or "East Coast Code", referring to Washington, D.C.) does (Wikipedia)

And now it feels like the west coast has won over the east coast, or maybe it recolonized it. In any case, Internet now christens emperors.

Dropdown for GitHub workflows input parameters Sometimes when we look at CI/CD tools embedded within git-based software repository manager like GitHub, GitLab or Bitbucket, we ran into a lack of some features. This time me and my DevOps/SRE team were facing a pain of not being able to have the option to create drop-downs within GitHub workflows using input parameters. Although this functionality is already available on other platforms such as Bitbucket, the specific client we were working on stored the code inside GitHub. At first I thought that someone has already solved this problem somehow, but doing an extensive search on the internet I found several angry GitHub users opening requests within the Support Community and even in the stack overflow. So I decided to create a solution for this, always thinking about simplicity and in a way that makes it easy to get this missing functionality. I started by creating an input array pattern using commas and using a tag (the selector) e.g brackets as the default value marker. Here is an example of what an input string would look like:

name: gh-action-dropdown-list-input
on:
  workflow_dispatch:
    inputs:
      environment:
        description: 'Environment'
        required: true
        default: 'dev,staging,[uat],prod'

Now the final question that would turn out to be the most complicated to deal with. How can I change the GitHub Actions interface to replace the input pattern we created earlier to a dropdown? The simplest answer I thought was to create a chrome and firefox extension that would do all this logic behind the scenes and replace the HTML input element with the selected tag containing the array values and leaving the tag value (selector) always as the default. All code was developed in pure JavaScript, open-source licensed under Apache 2.0 and available at https://github.com/arthurbdiniz/gh-action-dropdown-list-input.

Install extension

• Chrome
• Firefox

Once installed, the extension is ready to use and the final result we see is the Actions interface with drop-downs. :)

Configuring selectors Go to the top right corner of the browser you are using and click on the extension logo. A screen will popup with tag options. Choose the right tags for you and save it.

This action might require reloading the GitHub workflow tab.

---

Have fun using drop-downs inside GitHub. If you liked this project please share this post and if possible star within the repository. Also feel free to connect with me on LinkedIn: https://www.linkedin.com/in/arthurbdiniz

References

• https://github.community/t/can-workflow-dispatch-input-be-option-list/127338
• https://stackoverflow.com/questions/69296314/dropdown-for-github-workflows-input-parameters

Changes in version 0.0.14 (2021-10-17)

• Updated continuous integration to run on Linux only.
• Edited checkNonAscii.cpp for readability.
• More robust title display in intradayMarketMonitor.R.
• New C++-based function to read and convert encoding via the R-supplied iconv library, noted a potential variability.
• New function wday returning day of the week as integer.
• The signature to as.data.table was standardized.
• A new function rollMinMax was added illustrating use of the NumVec class from tidyCpp.
• The configure script can record the last commit date and sha1 to automate timestamping builds, but not activated in this release.
• checkCRANStatus() now works correctly for single-package lookups (Jordan Mark Barbone in #4).

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

> library(RcppQuantuccia)
> setCalendar("UnitedStates/FederalReserve")
> getHolidays(as.Date("2022-06-01"), as.Date("2022-06-30"))
[1] "2022-06-20"
> 

Changes in version 0.0.4 (2021-10-12)

• Allow for 'Null' calendar without weekends or holidays
• Switch CI use to r-ci
• Updated UnitedStates calendar to current QuantLib calendar
• Small updates to DESCRIPTION and README.md

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

source /path/to/collab-qa-tools/activate.sh

cqa-scanlogs   grep -v OK > todo

split --lines=30 --numeric-suffixes todo todo

cqa-fetchbugs --TODO=todo01

cqa-annotate --TODO=todo01

#!/bin/sh
set -eu
for todo in $@; do
  # force downloading bugs
  awk ' print(".bugs." $1) ' "$ todo "   xargs rm -f
  cqa-fetchbugs --TODO="$ todo "
  cqa-annotate \
    --template=template.txt.jinja2 \
    --TODO="$ todo "
done

From:   fullname   <  email  >
To: submit@bugs.debian.org
Subject:   package  : FTBFS with ruby3.0:   summary  
Source:   package  
Version:   version   split:'+rebuild'   first  
Severity: serious
Justification: FTBFS
Tags: bookworm sid ftbfs
User: debian-ruby@lists.debian.org
Usertags: ruby3.0
Hi,
We are about to enable building against ruby3.0 on unstable. During a test
rebuild,   package   was found to fail to build in that situation.
To reproduce this locally, you need to install ruby-all-dev from experimental
on an unstable system or build chroot.
Relevant part (hopefully):
 % for line in extract % >   line  
 % endfor % 
The full build log is available at
https://people.debian.org/~kanashiro/ruby3.0/round2/builds/3/  package  /  filename   replace:".log",".build.txt"  

######## ruby-cocaine_0.5.8-1.1+rebuild1633376733_amd64.log ########
--------- Error:
     Failure/Error: undef_method :exitstatus
     FrozenError:
       can't modify frozen object: pid 2351759 exit 0
     # ./spec/support/unsetting_exitstatus.rb:4:in  undef_method'
     # ./spec/support/unsetting_exitstatus.rb:4:in  singleton class'
     # ./spec/support/unsetting_exitstatus.rb:3:in  assuming_no_processes_have_been_run'
     # ./spec/cocaine/errors_spec.rb:55:in  block (2 levels) in <top (required)>'
Deprecation Warnings:
Using  should  from rspec-expectations' old  :should  syntax without explicitly enabling the syntax is deprecated. Use the new  :expect  syntax or explicitly enable  :should  with  config.expect_with(:rspec)    c  c.syntax = :should   instead. Called from /<<PKGBUILDDIR>>/spec/cocaine/command_line/runners/backticks_runner_spec.rb:19:in  block (2 levels) in <top (required)>'.
If you need more of the backtrace for any of these deprecations to
identify where to make the necessary changes, you can configure
 config.raise_errors_for_deprecations! , and it will turn the
deprecation warnings into errors, giving you the full backtrace.
1 deprecation warning total
Finished in 6.87 seconds (files took 2.68 seconds to load)
67 examples, 1 failure
Failed examples:
rspec ./spec/cocaine/errors_spec.rb:54 # When an error happens does not blow up if running the command errored before execution
/usr/bin/ruby3.0 -I/usr/share/rubygems-integration/all/gems/rspec-support-3.9.3/lib:/usr/share/rubygems-integration/all/gems/rspec-core-3.9.2/lib /usr/share/rubygems-integration/all/gems/rspec-core-3.9.2/exe/rspec --pattern ./spec/\*\*/\*_spec.rb --format documentation failed
ERROR: Test "ruby3.0" failed:
----------------
ERROR: Test "ruby3.0" failed:      Failure/Error: undef_method :exitstatus
----------------
package: ruby-cocaine
lines: 30
------------------------------------------------------------------------
s: skip
i: ignore this package permanently
r: report new bug
f: view full log
------------------------------------------------------------------------
Action [s i r f]:

• s - skip this package and do nothing. You can run cqa-annotate again later and come back to it.
• i - ignore this package completely. New runs of cqa-annotate won't ask about it again. This is useful if the package only fails in your rebuilds due to another package, and would just work when that other package gets fixes. In the Ruby transition this happens when A depends on B, while B builds a C extension and failed to build against the new Ruby. So once B is fixed, A should just work (in principle). But even if A would even have problems of its own, we can't really know before B is fixed so we can retry A.
• r - report a bug. cqa-annotate will expand the template with the data from the current log, and feed it to mutt. This is currently a limitation: you have to use mutt to report bugs. After you report the bug, cqa-annotate will ask if it should edit the TODO file. In my opinion it's best to not do this, and annotate the package with a bug number when you have one (see below).
• f - view the full log. This is useful when the extract displayed doesn't have enough info, or you want to inspect something that happened earlier (or later) during the build.

----------------
ERROR: Test "ruby3.0" failed:      Failure/Error: undef_method :exitstatus
----------------
package: ruby-cocaine
lines: 30
------------------------------------------------------------------------
s: skip
i: ignore this package permanently
1: 996206 serious ruby-cocaine: FTBFS with ruby3.0: ERROR: Test "ruby3.0" failed:      Failure/Error: undef_method :exitstatus  
r: report new bug
f: view full log
------------------------------------------------------------------------
Action [s i 1 r f]:

# For more information on what jobs are run see:
# https://salsa.debian.org/salsa-ci-team/pipeline
#
---
include:
  - https://salsa.debian.org/salsa-ci-team/pipeline/raw/master/salsa-ci.yml
  - https://salsa.debian.org/salsa-ci-team/pipeline/raw/master/pipeline-jobs.yml

variables:
   RELEASE: 'unstable'
   SALSA_CI_COMPONENTS: 'main contrib non-free'

variables:
   RELEASE: 'unstable'
   SALSA_CI_COMPONENTS: 'main contrib non-free'
   SALSA_CI_DISABLE_BUILD_PACKAGE_I386: 1

https://salsa.debian.org/<team>/<project>/-/settings/ci_cd

Key: SALSA_CI_EXTRA_REPOSITORY Value: deb https://deb.debian.org/debian/ sid contrib non-free

 
  "Sid": "Test existence of user",
  "Effect": "Allow",
  "Principal":  
    "AWS": "arn:aws:iam::111111111111:user/bob"
   ,
  "Action": "kms:DescribeKey",
  "Resource": "*"