January 2020 - Talk - lists.gtalug.org

Multi-Threading Work on GCC Link
by Nicholas Krause 23 Jan '20

23 Jan '20

Greetings All, For convenience and since the GCC folks want to move ahead as I've been personally busy with other things here is a link to my rough draft: https://docs.google.com/document/d/1po_RRgSCtRyYgMHjV0itW8iOzJXpTdHYIpC9gUM… I've yet to heard from the LLVM side but probably will discuss in with them at the next social in Toronto. Not sure if I will be at Cauldron this year again to continue my discussions on the project. In addition there has been some discussion about gold being updated like lld to be multi-threaded better as well for linker bottle-necked or linker intensive projects like chromuim and firefox are. If you have any questions as I probably won't be attending for the next few months you can email me here, Nick

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Wine for running Windows 10 apps on Linux gets big upgrade | ZDNet
by James Knott 23 Jan '20

23 Jan '20

Microsoft is working to improve Wine on Linux: https://www.zdnet.com/article/wine-for-running-windows-10-apps-on-linux-get… And Android too: https://www.androidpolice.com/2020/01/21/windows-compatibility-layer-wine-h… Micrsoft has certainly changed since Bill and Steve left.

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ThinkPads on special
by Giles Orr 23 Jan '20

23 Jan '20

This seems to be a yearly event: RedFlagDeals points out that ThinkPads are on special (many 45% off). Given their popularity on this list and their known compatibility with Linux, I hope it's okay to post this: https://www.redflagdeals.com/deal/computers-electronics/lenovo-up-to-50-of-… The cheapest model (ThinkPad X395) has an AMD chip (yay! About time with Intel's endless stream of security botches) and soldered-in memory (boo). Oh - and is currently ~$1000. -- Giles https://www.gilesorr.com/ gilesorr(a)gmail.com

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server question
by o1bigtenor 22 Jan '20

22 Jan '20

Greetings Can't find any somewhat current information (less than 2 years old) on what kind of an address to use on a server where its only for use by lan members - - - NOT for outside use. What I'm finding is at best 5 or 6 years old and then there is the stuff that's more like 10 or more years old. Debian has moved from iptables to nftables as of the latest release of stable (Buster or 10) and I haven't been able to find anything. Suggestions? TIA

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GCC Rust Frontend Bounty
by Nicholas Krause 21 Jan '20

21 Jan '20

Greetings, This may interest some people here including Hugh and others into Rust: https://www.bountysource.com/issues/86138921-rfe-add-a-frontend-for-the-rus… I'm not asking on behalf of the GCC project for funding but its more to let people know that the Rust community wants a rust frontend similar to gcc/g++ frontends for Rust. Regards, Nick

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Fedora user? Try "sudo dnf autoremove"
by D. Hugh Redelmeier 21 Jan '20

21 Jan '20

I've got a bunch of machines that I've updated to Fedora 31 from a previous version using dnf: <https://docs.fedoraproject.org/en-US/quick-docs/dnf-system-upgrade/> On several machines I get a scary notification error message every time I boot. Software Updates Failed Error calling StartServiceByName for org.freedesktop.fwupd: Timeout was reached This is a known bug with fwupd that has been fixed. But it seems to not be fixed enough. There is a work-around: sudo dnf autoremove That not only fixes/avoids the bug, but on my systems gets rid of a lot of packages that I didn't install and are no longer needed. Summary: just do autoremove and things will be better.

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Re-implementing xbattbar in Python
by Giles Orr 16 Jan '20

16 Jan '20

One of my favourite accessory programs for X is 'xbattbar' which puts a 3px wide line all along one side of your X screen with part of it red and part of it blue to indicate how much battery remains. Obviously there are many other battery indicators, and it's also obvious that this one has fallen out of favour: the original author vanished years ago (last updates circa 2010) and now it's no longer supported in Debian because the maintainer there has evidently lost interest. I'm not sure it was ever supported as a package in Fedora. By some judicious hacking of both the C and Python components from the most recent Debian source package, I've convinced it to build on Fedora 31. I'm not particularly happy with this solution as I'm well aware of my complete lack of C knowledge and only basic Python skills. What I'd like to do is to re-implement this idea in pure Python with a more flexible vision. 'xbattbar' already allows you to use an accessory script (a couple are provided, in Python) to feed values to xbattbar. So I was thinking of re-implementing it without the idea that it's just for batteries, but could show you hard drive usage or network throughput (although sample rate becomes an issue then: xbattbar allows adjustment of sample rate, but by default it's every 5 or 10 seconds). I think this is a good idea, but my limited Python experience barely extends beyond basic CLI and administrative scripts. So the questions for all of you are, has someone already done this, and if not, where do I start on figuring out how to draw a bar on an X screen without a window around it? -- Giles https://www.gilesorr.com/ gilesorr(a)gmail.com

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Any experience with "Linux on Windows"?
by sciguy＠vex.net 15 Jan '20

15 Jan '20

Hi I have been running dual boot into Windows and Linus for decades, but had a major problem with the latest Windows 10 in dual booting with Ubuntu. Apparently, I have heard (can't locate the source) booting into Linux can no longer be done on the latest major upgrade to Windows 10. And this was my direct experience when a Windows 10 upgrade this past September all but bricked by computer, rendering 50% of my storage inaccessible. I tried to check the boot area, and fix the situation with a Windows disk then a Linux disk, which rendered both systems unbootable. The problem pretty much solved itself when I downgraded to Windows 7, not touching Linux. Whether it boots or not may be moot, since Windows has offered many Linux distros to run in a windowed environment on top of Windows 10, kind of like VLC. That is to say, you go to the Microsoft Store, download a Linux distro, and it will install as a Windows application under Windows 10. Sample link: https://www.microsoft.com/en-ca/p/ubuntu-1804-lts/9n9tngvndl3q?activetab=pi… The link points to a copy of Ubuntu 18.04 LTS. I can see from the offerings, you can also install Debian, Suse, Fedora, and something called "Pengwin". Beware: some of these cost money, sometimes a fair chunk of it. It begs the question also as to how different are these distros from Cygwin? Sounds like these are just different attempts to duplicate what Cygwin is doing. BTW, Cygwin itself is not offered at the Microsoft store. Anyone have experiences with these weird versions of Linux running on Windows? I would like to hear about it. Any experience with how it would look with a dual monitor? Paul King

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End of independent web browsers
by Christopher Browne 15 Jan '20

15 Jan '20

The material takes somewhat extreme position, but it's curious that there are only 3 "content decryption modules" out there, Widevine (Google), Fairplay (Apple) and PlayReady (Microsoft), all of the vendors having expressed some reluctance to license to small fry. (Apple being uninterested in sublicensing.) https://boingboing.net/2020/01/08/rip-open-web-platform.html https://blog.samuelmaddock.com/posts/the-end-of-indie-web-browsers/ Google seems, marginally, the "good guys" here, licensing their CDM to various web browsers we know, but I'd not assume too much "goodness.". It's not good to need to be so dependent upon their good graces.a I'd never heard of these three technology names until today.

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Text of my slides
by Christopher Browne 15 Jan '20

15 Jan '20

Chris’ Intro to Kubernetes Christopher Browne GTALUG, January 2020 The Agenda A wee intro to k8s (because kubernetes is really long to type!) Some major components A progression of service evolution Chris’ crazy batch jobs, and my challenges Some useful tools k8s Originally a Google project called “Borg” It’s all about orchestrating the running of services in containers The “Borg” metaphor… Robotic services, lots of them, with sub- and sub-sub-services. Launched automatically. Relaunched on failure. Spread across a series of Borg Kubes. If one Kube blows up, there’s more! Kubernetes is a Greek word meaning “helmsman” or “pilot”; the one that steers a ship It uses Docker (usually); it’s the “opposite side” Major Components Starts with a Container system Docker, containerd, cri-o, rtklet, frakti, AWS Firecracker, gVisor, … Alternatives claim to be faster or more secure… are they??? Etcd - distributed key/value store for configuration DNS server - automatically managing hostnames inside the cluster Kube Proxy - maintains network rules so outside hosts can get at services inside the cluster Less Visible Components Kube API server - used to control node activities Kube scheduler - launches and destroys Pods Node controller - monitors each node (am I alive?) Replication Controller - add/drop Pods based on policy Endpoint Controller - connects Pods to form Services Visible or not, the Real Point of Kubernetes is to have the clusters self-monitoring and self-administering. A Progression of Sorts of Services Pods - a set of related containers sharing storage + IP Multiple containers so you add extra services via extra containers Use fluentd to aggregate collect logs, forward to ElasticSearch CronJob so a process runs periodically Job (run the thing once, more or less) DaemonSet (so each node has an instance of a service pod) ReplicationController - obsolesced ReplicaSet - obsolesced Deployment defining a ReplicaSet StatefulSet (needs stable network or storage) More Sophisticated Services Operators (think: “system operators”) PostgreSQL Operator Deploy multiple replica nodes (sync and async replication) Run backups using pgBackRest (including to S3) Automated failover via distributed consensus subsystem Automated recovery based on replicas or backups Component for managing users and permissions Capability to scale up by cloning DB clusters Sets up pgBouncer for connection pooling Includes health monitoring componentshttps://github.com/operator-framework/awesome-operators Yaml, Yaml Everywhere Manifests about how the pods in your services are configured, are written in YAML Configuration to pass to the pods, also YAML You are in a maze of twisty YAMLs, all nearly the same… I think I want an engine for generating YAML way more automatically (you’ll see why later…) Well, that’s why they have Helm - http://helm.sh Lots of systems use the Go language system for templating {{- if (.Files.Glob “myfile.conf”) }} {{ (.Files.Glob “myfile.conf”).AsConfig | indent 2 }} Configuration Pains Some things are painful… Twisty maze of YAML, Almost the same… Environment Variable Overlay Don’t call a config element PGPORT or PGHOST or PGDATABASE It’s kinda like running within a cron job... My Job Journey The stuff I build tends to be shell scripts running SQL queries Not a great fit for being an “endpoint” or a “service” Best fit appears to be k8s “Jobs” I have activities split into a series of job steps that pretty much need to be run serially, one after another The “best fit” isn’t to run a bunch of k8s Jobs, either No dependency system provided No indication that this is an area to expect much evolution So, I wrote 2 shell scripts as a “batch job controller” Receives a list of job steps to be run, JOBSTEPS Verifies that the steps are all valid (abort if not) Iterates across the steps in JOBSTEPS, in order: echo “start $step” > $LAUNCHMARKFILE Poll, waiting for the step to indicate it is done via seeing “done” in $JOBSTATEFILE job-controller.sh gets run by 1 container in the Job pod, logging as it goes Run-controller.sh Job-controller.sh Batch-job.sh Job-runner.sh There are a couple dozen containers, one per job step. Each runs via: job-runner.sh my-step-name [immediate] job-launcher function in batch-job.sh: Grabs configuration, turns it into a set of environment variable values Wait Loop; watch until $LAUNCHMARKFILE contains “start my-step-name”, It’s my turn now :-) Run the logic for this job step echo “done” > $JOBSTATEFILE to launch the next step A little Column A, a Little Column B... This Job pod has (at the moment) 22 containers Boy, that’s a lotta YAML!!! That’s a lotta containers!!! Some aspects are pretty clean Each job step gets its own distinct STDOUT logging It’s easy to identify which step is which At any given time, only one container is busy; others are lazy There’s only one Pod There’s only one container definition, used by all 22 containers Using one Pod means all the containers have easy access to common data files, no need to resort to GFS/gluster/NFS to share data Not terribly parallel, but that’s OK Helm Loosely, a package manager for k8s Implements Charts, that comprise sets of k8s Pods Provides a way of deploying locally-custom config, that, attached to a Chart, comprises a software Release Templates help you mix your configuration with defaults to provide a complete k8s manifest Requirements document dependencies (“we need a bunch of other Charts installed”) Some support for upgrading to newer versions of software Shell Tools Because k8s encourages long command lines, so you want any help you can get… Command completion - built-in source <(kubectl completion bash) source <(kubectl completion zsh) github.com/derailed/k9s - curses UI to manage clustergithub.com/ahmetb/kubectx - CLI help to smoothly switch between clusters (kubectx) and namespaces (kubens)github.com/jonmosco/kube-ps1 - k8s prompts for bash/zshgithub.com/abrochard/kubel - k8s buffer in Emacs Emacs Toolsgithub.com/abrochard/kubel - k8s buffer in Emacsgithub.com/chrisbarrett/kubernetes-el - k8s “porcelain”github.com/abrochard/kubernetes-helm - run Helm commands from within Emacs

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