KubeInvaders - Gamified Chaos Engineering Tool for Kubernetes

Some months ago, I released my latest project called KubeInvaders. The first time I shared it with the community was during an Openshift Commons Briefing session. Kubenvaders is a Gamified Chaos Engineering tool for Kubernetes and Openshift and helps test how resilient your Kubernetes cluster is, in a fun way.

CSI Ephemeral Inline Volumes

Typically, volumes provided by an external storage driver in Kubernetes are persistent, with a lifecycle that is completely independent of pods or (as a special case) loosely coupled to the first pod which uses a volume (late binding mode). The mechanism for requesting and defining such volumes in Kubernetes are Persistent Volume Claim (PVC) and Persistent Volume (PV) objects. Originally, volumes that are backed by a Container Storage Interface (CSI) driver could only be used via this PVC/PV mechanism. But there are also use cases for data volumes whose content and lifecycle is tied to a pod. For example, a driver might populate a volume with dynamically created secrets that are specific to the application running in the pod. Such volumes need to be created together with a pod and can be deleted as part of pod termination (ephemeral). They get defined as part of the pod spec (inline). Since Kubernetes 1.15, CSI drivers can also be used for such ephemeral inline volumes. The CSIInlineVolume feature gate had to be set to enable it in 1.15 because support was still in alpha state. In 1.16, the feature reached beta state, which typically means that it is enabled in clusters by default. CSI drivers have to be adapted to support this because although two existing CSI gRPC calls are used (NodePublishVolume and NodeUnpublishVolume), the way how they are used is different and not covered by the CSI spec: for ephemeral volumes, only NodePublishVolume is invoked by kubelet when asking the CSI driver for a volume. All other calls (like CreateVolume, NodeStageVolume, etc.) are skipped. The volume parameters are provided in the pod spec and from there copied into the NodePublishVolumeRequest.volume_context field. There are currently no standardized parameters; even common ones like size must be provided in a format that is defined by the CSI driver. Likewise, only NodeUnpublishVolume gets called after the pod has terminated and the volume needs to be removed.

Reviewing 2019 in Docs

Hi, folks! I’m one of the co-chairs for the Kubernetes documentation special interest group (SIG Docs). This blog post is a review of SIG Docs in 2019. Our contributors did amazing work last year, and I want to highlight their successes. Although I review 2019 in this post, my goal is to point forward to 2020. I observe some trends in SIG Docs–some good, others troubling. I want to raise visibility before those challenges increase in severity.

Springtime in Switzerland

During the same week I’ll also be giving a half-day seminar on Raku, which has been generously sponsored by EPFL and so will cost nothing to attend. It’s suitable for anyone who would like a quick but comprehensive overview of this remarkable new programming language. Besides making the Raku seminar entirely free, SIB/UNIL/EPFL have done an amazing job keeping the prices of the other classes extremely competitive...especially if you can claim a plausible association to any academic institution, either as a student or staff member. If you’re looking for some training that’s economical, practical, and just plain fun, in a location that’s central, civilised, and simply breathtaking, then this week in Switzerland might fit just the bill.

PyCoder’s Weekly: Issue #404 (Jan. 21, 2020)

Basic Data Types in Python

In this step-by-step course, you’ll dig into the basic data types that are built into Python.

Python 3.7.5 : Django security issues - part 002.

Python 3.7.5 : Use Django Formsets.

Django Formsets manage the complexity of multiple copies of a form in a view.  This simplifies the task of creating a formset for a form that handles multiple instances of a model.

Hunting gremlins

In the UTF-8 files I audit, the only invisible characters I expect to see... er... not see... are whitespace (hexadecimal 20), horizontal tab (09) and newline (linefeed; 0a). All others I call "gremlins". They include carriage return (0d), no-break space (c2 a0), soft hyphen (c2 ad) and another 62 control characters. Gremlins are a nuisance. One gremlin causes a shell to hang. Less evil gremlins lurk inside apparently OK strings and cause the strings to be processed weirdly. In the file "demo1", two of the strings contain no-break spaces (in different places), two contain soft hyphens (in different places) and three have no gremlins. 

A more expressive Bash prompt

Bash provides some interesting built-in specifiers for the prompt strings PS1. 

The Mozilla Developer Roadshow: Asia Tour Retrospective and 2020 Plans

November 2019 was a busy month for the Mozilla Developer Roadshow, with stops in five Asian cities —Tokyo, Seoul, Taipei, Singapore, and Bangkok. Today, we’re releasing a playlist of the talks presented in Asia. We are extremely pleased to include subtitles for all these talks in languages spoken in the countries on this tour: Japanese, Korean, Chinese, Thai, as well as English. One talk, Hui Jing Chen’s “Making CSS from Good to Great: The Power of Subgrid”, was delivered in Singlish (a Singaporean creole) at the event in Singapore! In addition, because our audiences included non-native English speakers, presenters took care to include local language vocabulary in their talks, wherever applicable, and to speak slowly and clearly. We hope to continue to provide multilingual support for our video content in the future, to increase access for all developers worldwide.

CRLite: Speeding Up Secure Browsing

CRLite pushes bulk certificate revocation information to Firefox users, reducing the need to actively query such information one by one. Additionally this new technology eliminates the privacy leak that individual queries can bring, and does so for the whole Web, not just special parts of it. The first two posts in this series about the newly-added CRLite technology provide background: Introducing CRLite: All of the Web PKI’s revocations, compressed and The End-to-End Design of CRLite. Since mid-December, our pre-release Firefox Nightly users have been evaluating our CRLite system while performing normal web browsing. Gathering information through Firefox Telemetry has allowed us to verify the effectiveness of CRLite.

Niko Matsakis: Async Interview #5: Steven Fackler

Hello! For the latest async interview, I spoke with Steven Fackler (sfackler). sfackler has been involved in Rust for a long time and is a member of the Rust libs team. He is also the author of a lot of crates, most notably tokio-postgres. I particularly wanted to talk to sfackler about the AsyncRead and AsyncWrite traits. These traits are on everybody’s list of “important things to stabilize”, particularly if we want to create more interop between different executors and runtimes. On the other hand, in [tokio-rs/tokio#1744], the tokio project is considering adopting its own variant traits that diverge significantly from those in the futures crate, precisely because they have concerns over the design of the traits as is. This seems like an important area to dig into!

wayland 1.17.91

This is the alpha release for Wayland 1.18. Here's a highlight of the
biggest changes:

- Add support for the Meson build system (autotools is still supported
  but will be removed in a future release)
- Add API to tag proxy objects to allow applications and toolkits to
  share the same Wayland connection
- Track wayland-server timers in user-space to prevent creating too
  many FDs
- Add wl_global_remove, a new function to mitigate race conditions with
  globals

Thanks to all contributors!

Full commit history below.

Antonio Borneo (1):
      log: remove "%m" from format strings by using strerror(errno)

Daniel Stone (2):
      build/doc: Ensure destination dir exists despite VPATH
      display-test: Remove unused variables

Drew DeVault (3):
      Document unusual wl_registry.bind new_id behavior
      Add .editorconfig
      Improve description of wl_surface

Emmanuel Gil Peyrot (2):
      cursor: Use memfd_create() when available
      wayland-shm: Don’t set SIGBUS handlers on unshrinkable fd

Emmanuele Bassi (2):
      Support running tests from different build directories
      Add Meson build

Harish Krupo (2):
      docs: Abort configure if docbook-xsl package is missing
      wayland.xml: document invalid_finish error in wl_data_offer.finish

Jiayuan Ren (1):
      adding O_RDWR flag in the open()

Jonas Ådahl (1):
      proxy: Add API to tag proxy objects

Joshua Watt (2):
      scanner: Add configure check for strndup
      Move wl_priv_signal to wayland-server-private.h

Leonid Bobrov (1):
      configure: detect libdl and librt

Liu Wenlong (1):
      server: Fix fake "Address already in use" error

Manuel Stoeckl (13):
      scanner: error when element names will not compile
      tests: Verify that wayland_scanner can catch bad identifiers
      protocol: clarify wl_display.delete_id description
      connection: do not abort when dup(fd) fails
      client: Ignore new requests if display has a fatal error
      client: Don't abort when sending a request fails
      tests: Test that send overflow doesn't abort
      tests: Fix race condition in send overflow test
      tests: Ensure that overflow test always overflows
      event-loop-test: Verify proper timer cancellation
      event-loop-test: Confirm distant timers do not fire
      event-loop: Track timer event sources in userspace
      event-loop-test: Add test to verify timer ordering

Marty E. Plummer (1):
      scanner: prepend protocol name to types symbol

Michael Forney (3):
      Use wl_container_of internally
      Avoid pointer arithmetic on `void *`
      protocol: fix typo in wl_data_offer.set_actions description

Mosè Giordano (1):
      Add $(RT_LIBS) to fixed-benchmark LD dependencies

Pekka Paalanen (2):
      configure.ac: reopen master for regular development
      scanner: include config.h from command line

Scott Anderson (1):
      wayland.xml: Make releases for multiple 'wl_surface.attach' undefined

Simon Ser (22):
      Add releasing.txt
      releasing: adapt for Wayland
      releasing: fixup section numbers
      protocol: allow to send a zero output refresh rate
      client: check event opcode in queue_event
      Update .editorconfig for Python
      Add an automated script to update wl_shm.format
      protocol: add a comment about the wl_shm.format script
      protocol: sync wl_shm.format with libdrm 2.4.99
      server: check global interface on bind
      tests: test that binding to a global with an interface mismatch fails
      protocol: invalid_method is sent on malformed request
      server: add wl_global_set_user_data
      server: add wl_global_remove
      tests: add a test for wl_global_remove
      build: check wayland-scanner version
      Revert "build: check wayland-scanner version"
      meson: use strict wayland-scanner mode
      autotools: use strict wayland-scanner mode
      build: check wayland-scanner version
      protocol: add missing enums for wl_data_device_manager.dnd_action
      build: bump to version 1.17.91 for the alpha release

asynts (1):
      doc: Expand the abbreviation "hw" to "hardware".

orbea (1):
      Add a missing -pthread to fix compile with slibtool.

git tag: 1.17.91

Wayland 1.18 Alpha Released With Meson Support, Connection Sharing

Wayland 1.18 is adding Meson build system support so that Autotools can be dropped in a future release, API support for allowing applications and toolkits to share the same Wayland connection, better handling over file descriptors, and wl_global_remove as a new function for mitigating race conditions with globals. There are also various test improvements, improved documentation, and various other fixes and minor improvements.

Linux on Embedded Ryzen with Radeon

American Micro Devices (AMD) has released the Ryzen processors which works very well with Linux. The embedded processor also contains a Graphical Processing Unit (GPU) which is an AMD Ryzen Vega. The board I am using is the IBase 918f-1605 to install Linux. Linux can be installed from a stock ISO, but the system does not perform as well unless using a special Linux kernel from AMD. It also helps to have the proper GPU driver for performance. Stability is much better with the AMD kernel they provide on their website.

Keith Packard Talks About The Early Politics Of X Window System + Code Licensing

At last week's Linux.Conf.Au conference was an interesting presentation by longtime X developer Keith Packard on the early days of the pre-X.Org X Window System, the collapse of Unix, and how his views formed on copyleft licenses for building thriving communities. Keith's LCA 2020 presentation is focused on the X happenings largely during the 80's and very early 90's. Keith's involvement goes back to the 80's during which he was employed at MIT as part of the X Consortium.

Keith Packard: lca2020

I just got back from linux.conf.au 2020 on Saturday and am still adjusting to being home again. I had the opportunity to give three presentations during the conference and wanted to provide links to the slides and videos.