- wlug - list.wlug.org.nz

Coincidence Of The Week (Or Not?)
by Lawrence D'Oliveiro 21 Jun '19

21 Jun '19

Just reading through this announcement <https://www.theregister.co.uk/2019/06/21/facebook_pyrobot/> of a new Python framework from Facebook called PyRobot, built on top of ROS (the Robot Operating System). Which led me to thinking of the origin of the word “robot”, which comes from a play by Karel Čapek, called “Rossum’s Universal Robots”, from 1920. And the original mastermind behind Python is named Guido van Rossum. And so another circle closes ...

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Enter The Virtual Supercomputer
by Lawrence D'Oliveiro 21 Jun '19

21 Jun '19

A company called Descartes Labs has become number 136 on the top500 supercomputer list just by paying for a large enough collection of nodes on its Amazon Web Services account <https://www.theregister.co.uk/2019/06/20/supercomputer_aws/>. However, Dr Paul Calleja, directory of the University of Cambridge Research Computing Services, argues that this is not really cost-effective compared to buying your own actual gear, and the I/O performance is not that good anyway. Such a cloud cluster may score well on LINPACK, but not so well on real-world supercomputing problems. Dr Calleja advocates using OpenStack to build a “hybrid” combination of on-premise physical hardware backed up by cloud services for those times when you need a bit of a (temporary) boost. And for learner supercomputer drivers, there is always the option of a Raspberry π cluster to practise on, before being allowed behind the wheel of a real big-iron machine ...

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Flushing All iptables Rules
by Lawrence D'Oliveiro 21 Jun '19

21 Jun '19

I have a script that I run on my Internet router machine to set up iptables rules for NAT forwarding and various other things. To ensure things are consistent, it starts by deleting any existing packet filter rules. The following sequence used to work for this: if test -f /proc/net/ip_tables_names; then for table in $(cat /proc/net/ip_tables_names); do iptables -t $table -F done fi However, while the file /proc/net/ip_tables_names still exists in current kernels, it no longer lists the names of tables for which rules are defined; instead, its contents are now always empty. It turns out there is now a new “nftables” interface for managing packet filter rules. The nice thing is, it has a command for listing all defined tables. For example, on my router machine, the command nft list tables prints out table ip filter table ip nat which means there are two tables named “filter” and “nat”, both part of the “ip” protocol stack. Interestingly, the nft(8) man page does not mention the “list tables” command (at least on Debian), only the more specific “list table «table»” form, which print out the rules within a given table. However, the nftables wiki <https://wiki.nftables.org/wiki-nftables/index.php/Quick_reference-nftables_…> does give all the details. As usual, the Arch Linux wiki entry <https://wiki.archlinux.org/index.php/Nftables> offers some additional useful info.

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next lug meet
by Ian Young 20 Jun '19

20 Jun '19

Greets If required I may be able to find a few words about a new project on Distrowatch last week named Resilient Linux. Listed on GitHub. https://github.com/marco-buratto/resilientlinux Seems to have some interesting aspects. It would help if the iso image could unzip successfully. Should anyone obtain such let me know. ~ Ian Y

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Microsoft’s Linux Strategy
by Lawrence D'Oliveiro 19 Jun '19

19 Jun '19

When Microsoft first embraced Docker and containers some years ago, no doubt people thought it was trying to nab some of that “virtualization-lite” action for its own Windows platform--at least I know I did. But with the release of WSL 2, which includes a full Linux kernel in Windows, it looks like this strategy has changed <https://www.theregister.co.uk/2019/06/18/the_future_of_docker_on_windows_is…>: The Docker news is of no interest to developers using Windows Containers, but there are not many of them. At Microsoft's Build conference last month, Gabe Monroy, lead program manager for the Azure Container Compute team, was asked whether Windows Containers are for legacy and Linux Containers for new projects. "I think that is a fair description," he said, demonstrating how the company's thinking on the subject has shifted. It seems Microsoft is now pushing the concept of develop on Windows, deploy on Linux. It is clearly hoping that those Linux deployments will happen on its Azure cloud, and so it still profits that way. Also, WSL 2 actually makes for worse Linux-Windows integration compared to WSL 1, which emulated the Linux APIs on top of Windows: Similarly, WSL 2 makes life better for developing Linux applications on Windows, but there are downsides. Running Linux in a VM as opposed to redirecting system calls is better for compatibility but inherently worse for integration. One aspect of this is that in WSL 2 I/O performance to files within the Linux VM is much faster, but I/O performance between Linux and the host is worse. Another is that WSL 2 has no access to serial or USB ports. Seems to me the obvious way to fix this, at least partially, is to flip things round, so instead of virtualizing Linux on top of Windows, you virtualize Windows on top of Linux. Then both your development and deployment platforms become fundamentally Linux-based. How long before that happens?

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Birthplace Of BASIC Gets A Memorial Marker
by Lawrence D'Oliveiro 18 Jun '19

18 Jun '19

The US state of New Hampshire has added a marker <https://www.theregister.co.uk/2019/06/17/plaque_for_basic_birthplace_new_ha…> commemorating the creation of the BASIC programming language by professors Kemeny and Kurtz and a bunch of their students at Dartmouth College, back in 1964. The marker is not actually on College property, but on the nearest available state highway location.

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Linux PCs, Servers, Gadgets Can Be Crashed by 'Ping of Death' Network Packets
by Peter Reutemann 17 Jun '19

17 Jun '19

'The Register reports that it is possible to crash network-facing Linux servers, PCs, smartphones and tablets, and gadgets, or slow down their network connections, by sending them a series of maliciously crafted packets. It is also possible to hamper FreeBSD machines with the same attack. Patches and mitigations are available, and can be applied by hand if needed, or you can wait for a security fix to be pushed or offered to your at-risk device. A key workaround is to set /proc/sys/net/ipv4/tcp_sack to 0. At the heart of the drama is a programming flaw dubbed SACK Panic aka CVE-2019-11477: this bug can be exploited to remotely crash systems powered by Linux kernel version 2.6.29 or higher, which was released 10 years ago.' -- source: https://linux.slashdot.org/story/19/06/17/2018227 Cheers, Peter -- Peter Reutemann Dept. of Computer Science University of Waikato, NZ +64 (7) 858-5174 http://www.cms.waikato.ac.nz/~fracpete/ http://www.data-mining.co.nz/

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RKWard on Linux Mint 19.1 fails to start up
by Peter Reutemann 17 Jun '19

17 Jun '19

Hi everyone In case you're trying to use RKWard (GUI environment for the R language) on Linux Mint 19.1 and you keep getting the following error message: "The KDE installation could not be found (kreadconfig5). When moving / copying RKWard, make sure to copy the whole application folder, or create a shorcut / link, instead." Then simply install the following package: libkf5config-bin For instance, you can do this using apt-get: sudo apt-get install libkf5config-bin -- source: https://rkward-devel.narkive.com/M5x9XHCk/rkward-0-7-0-is-available Cheers, Peter -- Peter Reutemann Dept. of Computer Science University of Waikato, NZ +64 (7) 858-5174 http://www.cms.waikato.ac.nz/~fracpete/ http://www.data-mining.co.nz/

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A New Hidden Way of Web Browser Profiling, Identification and Tracking
by Peter Reutemann 17 Jun '19

17 Jun '19

'Researchers from Austria's Graz University of Technology "have devised an automated system for browser profiling using two new side channel attacks that can help expose information about software and hardware," reports The Register. The researchers recently presented a paper titled "JavaScript Template Attacks: Automatically Inferring Host Information for Targeted Exploits," which The Register says "calls into question the effectiveness of anonymized browsing and browser privacy extensions... " Long-time Slashdot reader Artem S. Tashkinov shared their report: One of the side-channel attacks developed for JavaScript Template Attacks involve measuring runtime differences between two code snippets to infer the underlying instruction set architecture through variations in JIT compiler behavior. The other involves measuring timing differences in the memory allocator to infer the allocated size of a memory region. The boffins' exploration of the JavaScript environment reveals not only the ability to fingerprint via browser version, installed privacy extension, privacy mode, operating system, device microarchitecture, and virtual machine, but also the properties of JavaScript objects. And their research shows there are far more of these than are covered in official documentation. This means browser fingerprints have the potential to be far more detailed -- have more data points -- than they are now. The Mozilla Developer Network documentation for Firefox, for example, covers 2,247 browser properties. The researchers were able to capture 15,709. Though not all of these are usable for fingerprinting and some represent duplicates, they say they found about 10,000 usable properties for all browsers.' -- source: https://yro.slashdot.org/story/19/06/16/232241 Cheers, Peter -- Peter Reutemann Dept. of Computer Science University of Waikato, NZ +64 (7) 858-5174 http://www.cms.waikato.ac.nz/~fracpete/ http://www.data-mining.co.nz/

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next meeting - topics?
by Peter Reutemann 14 Jun '19

14 Jun '19

Hi everyone At the moment, we don't have a speaker for this month's meeting (June 24th): https://www.meetup.com/WaikatoLinuxUsersGroup/events/257884282/ Any volunteers? I was thinking of quickly demoing how to generate .deb packages from your code - I've forked an unmaintained plugin, which does that for Maven projects (= java based), i.e., I know a teeny bit about the process. Apart from the command-line tools, there are also GUI tools available for achieving this. Cheers, Peter -- Peter Reutemann Dept. of Computer Science University of Waikato, NZ +64 (7) 858-5174 http://www.cms.waikato.ac.nz/~fracpete/ http://www.data-mining.co.nz/

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