Kubernetes: Basic Concepts

I have been diving into Kubernetes lately, for both personal and $dayjob reasons. With the combined effect of my attendance at a recent Kubernetes workshop by Kelsey Hightower (on his very last day at CoreOS no less!) and also having the amazing opportunity to attend the inaugural and sold-out Kubecon that starts today, I figured it’s high time I tackle a “basics of Kubernetes” post.

This blog post is meant to serve as a very high-level introduction to Kubernetes concepts and components. If you are looking to stand up your own cluster, I encourage you to read the exceptional Kubernetes documentation. No, really. They’re exceptionally good docs.

Scheduling 101

Within the context of computer operating systems, the “scheduler” is the component that manages the assignment of compute resources to running processes. Especially in the early days before parallel computing and multicore systems, it was crucial to very carefully manage how much CPU time was allowed for the various running processes, so that the user could have a seamless experience. Even today with multicore systems, this is important to ensure that each core is utilized as evenly as possible, or at least to meet certain SLA requirements.

With the Continue reading

Kubernetes: Basic Concepts

I have been diving into Kubernetes lately, for both personal and $dayjob reasons. With the combined effect of my attendance at a recent Kubernetes workshop by Kelsey Hightower (on his very last day at CoreOS no less!) and also having the amazing opportunity to attend the inaugural and sold-out Kubecon that starts today, I figured it’s high time I tackle a “basics of Kubernetes” post. This blog post is meant to serve as a very high-level introduction to Kubernetes concepts and components.

Kubernetes: Basic Concepts

I have been diving into Kubernetes lately, for both personal and $dayjob reasons. With the combined effect of my attendance at a recent Kubernetes workshop by Kelsey Hightower (on his very last day at CoreOS no less!) and also having the amazing opportunity to attend the inaugural and sold-out Kubecon that starts today, I figured it’s high time I tackle a “basics of Kubernetes” post. This blog post is meant to serve as a very high-level introduction to Kubernetes concepts and components.

Changing Passwords with cloud-init

Generally speaking, when launching instances in a cloud environment (such as AWS or an OpenStack-based cloud), the preferred/default way of accessing that instance is via SSH using an injected SSH key pair. There are times, though, when—for whatever reason—this approach won’t work. (I’ll describe one such situation below.) In such instances, it’s possible to configure cloud-init, the same tool used to inject SSH keys, to change passwords for user accounts. Here’s how.

Please note that this is a total hack. (Do NOT use this for any sort of production workload!) That being said, sometimes things like this are necessary to complete preliminary evaluations of a new technology, new product, or new architecture. In my case, I had a demo environment (using DevStack) that I needed to get up and running, and the instances would not have any external connectivity. This meant I was limited to console access only—hence, SSH keys are useless. The only means of access would be via password login through the console. So, I found this snippet of cloud-init code:

#cloud-config
chpasswd:
  list: |
    user1:password1
    user2:password2
    user3:password3
  expire: False

For this particular use case, I needed to change the default user on the Ubuntu Continue reading

Kubecon Liveblog: Opening Keynote

This is a liveblog of the opening keynote at the inaugural Kubernetes conference, Kubecon, taking place this week at the Palace Hotel in San Francisco. Brendan Burns, Senior Staff Software Engineer at Google, is delivering the opening keynote. Burns is a co-founder of the Kubernetes project.

Burns starts out with a quick review of a bit of Kubernetes history, and reviews the broad diversity of submitters that are participating in the development of Kubernetes. He doesn’t spend much time there, though, and quickly transitions into a “where are we going?” discussion.

He says that Kubernetes wasn’t really about containers, or scheduling; it was really about making reliable, scalable, agile distributed systems a CS101 exercise. Kubernetes is really about making it easier to build distributed systems, to scale distributed systems, to update distributed systems, and to make distributed systems more reliable. Burns demonstrates how Kubernetes makes this easier by showing a recorded demo of scaling Nginx web servers up to handle 1 million requests per second, and then updating the Nginx application while still under load.

After the demo completes, Burns takes a few minutes to break down the architecture behind the demonstration. “Loadbots,” managed by a Kubernetes replication controller, Continue reading

Teen hackers strike again, allegedly gain access to U.S. arrest records database

A group of teenage hackers going by the name of “Crackas With Attitude” (CWA) are on a rampage, breaking into federal systems to embarrass the U.S. government.After gaining access to the personal AOL email account of CIA Director John Brennan last month, the teenagers reportedly broke into the Comcast email account of FBI Deputy Director Mark Giuliana’s wife, dumped personal details of thousands of government employees and then claimed to have gained access to the national Joint Automated Booking System, JABS, a database of arrest records, the FBI’s Internet Crime Complaint Center and the FBI’s Virtual Command Center.To read this article in full or to leave a comment, please click here

Teen hackers strike again, allegedly gain access to US arrest records database

A group of teenage hackers going by the name of “Crackas With Attitude” (CWA) are on a rampage, breaking into federal systems to embarrass the U.S. government.After gaining access to the personal AOL email account of CIA Director John Brennan last month, the teenagers reportedly broke into the Comcast email account of FBI Deputy Director Mark Giuliana’s wife, dumped personal details of thousands of government employees and then claimed to have gained access to the national Joint Automated Booking System, JABS, a database of arrest records, the FBI’s Internet Crime Complaint Center and the FBI’s Virtual Command Center.To read this article in full or to leave a comment, please click here

Ring’s Ring: Automating the Doorbell

Of all of the things that you might think of upgrading as you move into home or premises automation your doorbell may not immediately spring to mind. When it comes to entryway monitoring and security, the solution is usually to use a camera and sometimes a wireless doorbell. A company called, appropriately, Ring, has come out with a solution called, also appropriately, Ring. The Ring is a wireless device with a built in wide angle 720p HD camera, microphone, speaker, and pushbutton. The device communicates over your WI-Fi network (2.4 gHz 802.11 b/g/n with WPA2, WPA or 64-bit WEP) to Ring’s cloud services which allows you, on your iOS, Android, or Windows 10 device, to see and talk to whoever is outside your door from wherever you are as well as make a video record of activity.  To read this article in full or to leave a comment, please click here

From Sublime Text Markdown to Evernote Conversion

Who loves Sublime Text? Who also loves Evernote for organizing notes? Well, I do, and hopefully you do as well, which is why you’re reading this. Sublime Text 3 is my goto text editor of choice. I...

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From Sublime Text Markdown to Evernote Export

Who loves Sublime Text? Who also loves Evernote for organizing notes? Well, I do, and hopefully you do as well, which is why you’re reading this. Sublime Text 3 is my goto text editor of...

[[ Summary content only, you can read everything now, just visit the site for full story ]]

Worth Reading: Better than Reno

Critically, today’s Internet assumes that most of the network’s resources are devoted to passing TCP traffic, and it also assumes that the flow control algorithms used by these TCP sessions all behave in approximately similar ways. If the switching and transmission resources of the network are seen as a common resource, then the assumption about the uniform behaviour of TCP sessions implies that these end-to-end transport sessions will behave similarly under contention. via circle id

The post Worth Reading: Better than Reno appeared first on 'net work.

Google Play Services 8.3 simplifies Android sign-in to a single tap

Google has updated Google Play Services. Users will notice changes from these updates in their apps quickly. For most Android users, Play Services remains out of sight and under the hood, serving apps with application programming interfaces (API), OAuth 2.0 identity services, security, malware scanning, and other mobile services.With the release of Google Play 8.3, Google has changed the sign-in button to make it work more like Chrome's web sign-in. When a new app that uses this updated Play Services release is downloaded, the developer can present the new branded sign-in button: Google This is a big interaction fix for users who previously had to select from multiple accounts, create new profiles, and grant user permissions just to sign into an app. It wouldn't be noticeable except for all the streamlined web sign-ins available, such as Google, Facebook, and Twitter, that reduce sign-in to a click. Now Android sign in to apps is reduced to a tap.To read this article in full or to leave a comment, please click here

PlexxiPulse—One Year In

It’s hard to believe that it has been a year since Rich Napolitano took the helm as CEO of Plexxi. Since last November, he’s implemented a new strategic vision, formed an exclusive channel distribution agreement with Arrow Electronics and raised a new round of funding. This week, in a profile published in eWeek, enterprise reporter Jeff Burt describes why Rich joined Plexxi and chronicles Plexxi’s successes under his leadership. Take a look. It’s definitely worth a read  before you head out for the weekend. We’re excited to see what Rich’s second year at Plexxi has in store for us, our customers, partners and the industry!

Below please find a few of our top picks for our favorite news articles of the week. Enjoy!

CIO Review: How to Create the Network of the Future (pg. 48-49)
By Rich Napolitano
IT is changing. The advent of Big Data, the Internet of Things and mobile has massively increased the amount of data we are creating, storing and moving – putting an increasing strain on the piece at the center of it all: the network. More data is a reality. It empowers users around the world with more information than they could ever Continue reading

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