CoreDNS-1.0.0 Release

  • By John Belamaric. Originally posted on

    We are pleased to announce the release of CoreDNS-1.0.0!

    Release 1.0.0 and other recent releases have focused on improving the performance and functionality of the kubernetes plugin, since CoreDNS is now on track to eventually replace kube-dns as the default cluster DNS in Kubernetes.

    As part of the Kubernetes proposal, we have shown that CoreDNS not only provides more functionality than kube-dns, but performs much better while using less memory. In our tests,CoreDNS running against a cluster with 5000 services was able to process 18,000 queries per second using 73MB of RAM, while kube-dns achieved 7,000qps using 97MB of RAM. This can be partial ascribed to CoreDNS simpler runtime – a single process instead of a combination of several processes.

    CoreDNS also implements a number of Kubernetes-related features that are not part of kube-dns, including:

    • Filtering of records by namespace
    • Filtering of records by label selector
    • pods verified mode, which ensures that a Pod exists before returning an answer for a pod.cluster.local query
    • endpoint_pod_names which uses Pod names for service endpoint records if the hostname is not set
    • autopath which provides a server-side implementation of the namespace-specific search path. This can cut down the query latency from pods dramatically.

    As a general-purpose DNS server, CoreDNS also enables many other use cases that would be difficult or impossible to achieve with kube-dns, such as the ability to create custom DNS entries.

    We are excited to continue our contributions to the Kubernetes community, and CoreDNS is being incorporated as a 1.9 alpha feature into a variety of Kubernetes deployment mechanisms, including upcoming versions of kubeadm, kops, minikube, and kubespray.

    Of course, there is more to 1.0.0 than just the Kubernetes work. See below for the details on all the changes.


    • Fixed a bug in the gRPC server that prevented dnstap from working with it.
    • Additional fuzz testing to ferret out obscure bugs.
    • Documentation and configuration cleanups.


    • log no longer accepts stdout in the configuration (use of a file was removed in a previous release). All logging is always to STDOUT. This is a backwards incompatible change, so be sure to check your Corefile for this.
    • health now checks plugins that support it for health and reflects that in the server health.
    • kubernetes now shows healthy only after the initial API sync is complete.
    • kubernetes has bug fixes and performance improvements.
    • kubernetes now has an option to use pod names instead of IPs in service endpoint records when the hostname is not set.
    • metrics have been revised to provide better histograms. You will need to change your Prometheus queries as metric names have changed to comply with Prometheus best practices.
    • erratic now supports the health check.


    The following people helped with getting this release done: Andy Goldstein, Ben Kochie, Brian Akins, Chris O’Haver, Christian Nilsson, John Belamaric, Max Schmitt, Michael Grosser, Miek Gieben, Ruslan Drozhdzh, Uladzimir Trehubenka, Yong Tang.

    If you want to help, please check out one of the issues and start coding!

    For documentation and help, see our community page.

    John Belamaric
    Published: <time datetime=“2017-12-01T22:43:43+00:00”>1 Dec, 2017</time> and tagged 1.0.0, Notes and Release using 503 words.


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    The post CoreDNS-1.0.0 Release appeared first on The Linux Foundation.

Tmux Commands

screen and tmux

A comparison of the features (or more-so just a table of notes for accessing some of those features) for GNU screen and BSD-licensed tmux.

The formatting here is simple enough to understand (I would hope). ^ means ctrl+, so ^x is ctrl+x. M- means meta (generally left-alt or escape)+, so M-x is left-alt+x

It should be noted that this is no where near a full feature-set of either group. This - being a cheat-sheet - is just to point out the most very basic features to get you on the road.

Trust the developers and manpage writers more than me. This document is originally from 2009 when tmux was still new - since then both of these programs have had many updates and features added (not all of which have been dutifully noted here).

Action tmux screen
start a new session tmux OR
tmux new OR
tmux new-session
re-attach a detached session tmux attach OR
tmux attach-session
re-attach an attached session (detaching it from elsewhere) tmux attach -d OR
tmux attach-session -d
screen -dr
re-attach an attached session (keeping it attached elsewhere) tmux attach OR
tmux attach-session
screen -x
detach from currently attached session ^b d OR
^b :detach
^a ^d OR
^a :detach
rename-window to newname ^b , <newname> OR
^b :rename-window <newn>
^a A <newname>
list windows ^b w ^a w
list windows in chooseable menu ^a "
go to window # ^b # ^a #
go to last-active window ^b l ^a ^a
go to next window ^b n ^a n
go to previous window ^b p ^a p
see keybindings ^b ? ^a ?
list sessions ^b s OR
tmux ls OR
tmux list-sessions
screen -ls
toggle visual bell ^a ^g
create another window ^b c ^a c
exit current shell/window ^d ^d
split window/pane horizontally ^b " ^a S
split window/pane vertically ^b % ^a |
switch to other pane ^b o ^a <tab>
kill the current pane ^b x OR (logout/^D)
collapse the current pane/split (but leave processes running) ^a X
cycle location of panes ^b ^o
swap current pane with previous ^b {
swap current pane with next ^b }
show time ^b t
show numeric values of panes ^b q
toggle zoom-state of current pane (maximize/return current pane) ^b z
break the current pane out of its window (to form new window) ^b !
re-arrange current panels within same window (different layouts) ^b [space]
Kill the current window (and all panes within) ^b killw [target-window]
  • Open Source Summit

    Join us in Edinburgh! Submit a proposal to speak by July 1 for Open Source Summit & ELC + OpenIoT Summit Europe.

    Submit a proposal to speak at Open Source Summit Europe & ELC + OpenIoT Summit Europe, taking place October 22-24, 2018, in Edinburgh, UK, and share your knowledge and expertise with 2,000+ open source technologists and community leaders. Proposals are being accepted through 11:59pm PDT, Sunday, July 1.

    This year’s tracks and content will cover the following areas at Open Source Summit Europe:

    Cloud Native Apps/Serverless/Microservices Infrastructure & Automation (Cloud/Cloud Native/DevOps) Linux Systems Artificial Intelligence & Data Analytics Emerging Technologies & Wildcard (Networking, Edge, IoT, Hardware, Blockchain) Community, Compliance, Governance, Culture, Open Source Program Management (Open Collaboration Conference track) Diversity & Inclusion (Diversity Empowerment Summit) Innovation at Apache/Apache Projects TODO / Open Source Program Management

    View the full list of suggested topics for Open Source Summit Europe.

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    Audio, Video, Streaming Media and Graphics Security System Size, Boot Speed Real-Time Linux – Performance, Tuning and Mainlining SDKs for Embedded Products Flash Memory Devices and Filesystems Build Systems, Embedded Distributions and Development Tools Linux in Devices such as Mobile Phones, DVRs, TVs, Cameras, etc Use of Linux in Automotive Drones and Robots Linux in the Internet of Things Practical Experiences and War Stories Standards Public Infrastructure Industrial Automation

    This year’s tracks and content will cover the following areas at ELC:

    Suggested OpenIoT Summit Topics:

    Real-Time OS (Zephyr, RIOT, MyNewt, FreeRTOS, NuttX, mbed and Others) Outside World Meets IoT (Sensor Interaction, Low Footprint, Connected Sensors, EMF/RFI Impact) Bootloaders, Firmware & Updates Containers Distributed Edge Application Technologies On-device Analytics Blockchain for Constrained Devices Device Management Power Management Configuration Management Developing for Security Safety Considerations Certifications – Lessons Learned Taking Devices to Product

    View the full list of suggested topics for ELC + OpenIoT Summit Europe.


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  • Open Source Guides

    The Open Source Guides for the Enterprise are now available in Chinese.

    The popular Open Source Guides for the Enterprise, developed by The Linux Foundation in collaboration with the TODO Group, are now available in Chinese. This set of guides provides industry-proven best practices to help organizations successfully leverage open source.

    “Making these resources available to Chinese audiences in their native language will encourage even greater adoption of and participation with open source projects,” said Chris Aniszczyk, CTO of Cloud Native Computing Foundation and co-founder of the TODO Group. The guides span various stages of the open source project lifecycle, from initial planning and formation to winding down a project.

    The 10 guides now available in Mandarin include topics such as:

    Creating an Open Source Program by Chris Aniszczyk, Cloud Native Computing Foundation; Jeff McAffer, Microsoft; Will Norris, Google; and Andrew Spyker, Netflix Using Open Source Code by Ibrahim Haddad, Samsung Research America Participating in Open Source Communities by Stormy Peters, Red Hat; and Nithya Ruff, Comcast Recruiting Open Source Developers by Guy Martin, Autodesk; Jeff Osier-Mixon, Intel Corporation; Nithya Ruff; and Gil Yehuda, Oath Measuring Your Open Source Program’s Success by Christine Abernathy, Facebook; Chris Aniszczyk; Joe Beda, Heptio; Sarah Novotny, Google; and Gil Yehuda

    The translated guides were launched at the LinuxCon + ContainerCon + CloudOpen China conference in Beijing, where The Linux Foundation also welcomed Chinese Internet giant Tencent as a Platinum Member.

    The post Open Source Guides for the Enterprise Now Available in Chinese appeared first on The Linux Foundation.

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