Kelsey Hightower gave a really interesting talk at ContainerSched about how to create your own scheduler using the Kubernetes HTTP API. The talk was awesome. It’s incredible to see what kind of things you can do with a base system as good as Kubernetes.
However, I missed one thing. The example provided by Kelsey was a Go application. Which is the main language used with Kubernetes. So, if check that code without any context, you might think it’s using some kind of Kubernetes internal packages. But it’s not! It’s a standalone piece of code that happens to make some HTTP calls.
To illustrate this point, I decided to write my own scheduler, in a different language. In my case,Elixir, because that’s the language I happen to be learning at the moment.
Desktop development environments for Mac and Windows use native virtualization for speed and boost Docker’s out-of-the-box cluster management and scheduling system.
Docker unveiled version 1.12 of its core software-containerization system today, along with the first full desktop editions of the software for development on Mac and Windows machines. Docker for Mac and Docker for Windows, which debuted as beta products earlier this year, provide developers on those platforms with something that had always seemed out of reach: the ability to do container work with Docker as a native application.
It follows official guide lines and updates undercloud with OVSIntPort vlan10 for br-ctlplane OVS bridge making posible HA and/or Ceph overcloud deployments with “Network Isolation” enabled. See also upstream commit https://review.openstack.org/#/c/329438/ been done by Marios Andreou on 06/14/2016
Firewalls screen data coming in and out of computer networks, blocking unauthorized access and halting traffic from unsafe Internet sources. A firewall is a barrier between you and the internet. UFW is is uncomplicated firewall for Ubuntu and Debian based server. It is used for managing a Linux firewall and aims to provide an easy to use interface for the user.
The first article in this XenServer 7 Series covered how to install/upgrade a single XenServer host. Most XenServer installs are likely to be in a pool of many XenServer hosts.
This article will cover the process of an entire XenServer pool upgrade. The final component will cover some house keeping with the guests running on the XenServer hosts.
[[ This is a content summary only. Visit my website for full links, other content, and more! ]]
Open source software is experiencing huge growth, with a staggering 64% of companies currently participating in open source projects. But you probably know that already. What’s more interesting to look at is how to sell it, and with a little luck, make some money to help support the people who develop your software and sustain your project.
Why we love open source software
Having a deep understanding of why so many organizations use and trust open source is key when it comes to selling it. As one of our own GitLab colleagues explains, it “allows for a level of transparency which closed sourced products do not have; …”
Last week, Facebook launched Create React App, a new project that helps React developers get started with their new projects. Turns out, that was only part of the story. Create React App was also the first project to enter the Facebook Incubator on GitHub.
The Facebook Incubator is the company’s new process for releasing open-source projects and ensuring that they do well in the long run. The best way to think of it is as a beta stage or proving ground for new open source projects from Facebook.
As Facebook’s head of open source James Pearce told me, the idea here is to better manage the life cycle of these projects.
Time is money, as goes an old saying, therefore you need to manage it very well. This then calls for proper planning of your daily schedule, future events, appointments and several other daily activities…
You can only achieve this efficiently and flexibly by using a calendar application especially on your Linux desktop. In this article, we shall walk through a brief review of some of the best calendar applications that can help us plan and manage our daily lives.
[[ This is a content summary only. Visit my website for full links, other content, and more! ]]
This is the demo project for Tibbo’s MQTT library. The project demonstrates how easy it is to create sophisticated network-enabled applications in Tibbo BASIC and Tibbo C. The code is extremely simple and easy to understand. Take this app and modify it for your MQTT needs.
To illustrate the use of the MQTT library, we have created two simple Tibbo BASIC applications called “mqtt_publisher” and “mqtt_subscriber”.
In our MQTT demo, the publisher device is monitoring three buttons (Tibbits #38). This is done through the keypad (kp.) object.
The three buttons on the publisher device correspond to the red, yellow, and green LEDs (Tibbits #39) on the subscriber device.
As buttons are pushed and released, the publisher device calls mqtt_publish() with topics “LED/Red”, “LED/Green”, and “LED/Red”. Each topic’s data is either 0 for “button released” or 1 for “button pressed”. The related code is in the on_kp() event handler.
The subscriber device subscribes to all three topics with a single call to mqtt_sub() and the line “LED/#”. This is done once, inside callback_mqtt_connect_ok().
With every notification message received from the server, the subscriber device gets callback_mqtt_notif() invoked. The LEDs are turned on and off inside this functions’s body.
Testing the MQTT demo
The demo was designed to run on our TPS3 boards, but you can easily modify it for other devices.
Open source is the new normal for startups and large enterprises looking to stay competitive in the digital economy. That means that open source is now also a viable long-term career path.
“It is important to start thinking about the career road map, and the pathway that you can take and how Linux and open source in general can help you meet your career goals,” said Clyde Seepersad, general manager of training at The Linux Foundation, in a recent webinar.
Certification is one clear path with real career benefits. Forty-four percent of hiring managers in our recent 2016 Open Source Jobs Report said they’re more likely to hire certified candidates. And 76 percent of open source pros surveyed believe certifications lead to a career boost.
The Linux Foundation Certified System Administrator (LFCS) and Certified Engineer (LFCE) exams are great opportunities for sysadmins to polish and prove their skills. The exams are available online to anyone in the world at any time. They’re also performance based, working within a Linux server terminal and overseen by a proctor. Because the format is not multiple choice, even seasoned pros will need some preparation in order to avoid common mistakes and complete the exam within the time limit.
To help you prepare for the certification exam, and a long and successful sysadmin career, we’ve gathered some tips, below, from Linux Foundation certified sysadmins who have completed the LFCS or LFCE exams.
Chris van Horn, LFCS
1. Practice
“Experience is key. Spin up a VM, take a fresh snapshot of it and go to work applying all the requirements of the exam in practice. When you feel you have satisfied all the exam topics thoroughly, apply that fresh snapshot to revert changes and begin again until it is second nature. Also, feel comfortable with man pages; they are your best friend when Google is not an option.”
“The best preparation is your experience. If you feel that you have enough experience with the topics required by the exam, you can give it a try. Otherwise, you have to work hard to get those skills.
Don’t think that in a short time you can learn everything.”
4. Understand the material, don’t just memorize it
“Forget recipes, it’s not about memorization. Understand what are you doing by reading some books and documentation that give you a deep background of the tasks you’ll perform at the exam and in real life.
“For experienced professionals, I recommend that they prepare the environment for the exam, and follow the instructions. It’s not a difficult exam if you work daily with Linux.
On the other hand, for newcomers, apart from having a look to open/free resources, I just encourage them to set up a Linux environment at home and get their hands dirty!!”
“Make sure you love what you are doing, and do not forget to have fun, to experiment, and then to do it all over again and again, and make sure you learn something new each time.”
