Kubernetes Blog

Introducing the Kubernetes OpenStack Special Interest Group

April 22 2016

Editor’s note: This week we’re featuring Kubernetes Special Interest Groups; Today’s post is by the SIG-OpenStack team about their mission to facilitate ideas between the OpenStack and Kubernetes communities. 

The community around the Kubernetes project includes a number of Special Interest Groups (SIGs) for the purposes of facilitating focused discussions relating to important subtopics between interested contributors. Today we would like to highlight the Kubernetes OpenStack SIG focused on the interaction between Kubernetes and OpenStack, the Open Source cloud computing platform.

There are two high level scenarios that are being discussed in the SIG:

  • Using Kubernetes to manage containerized workloads running on top of OpenStack
  • Using Kubernetes to manage containerized OpenStack services themselves

In both cases the intent is to help facilitate the inter-pollination of ideas between the growing Kubernetes and OpenStack communities. The OpenStack community itself includes a number of projects broadly aimed at assisting with both of these use cases including:

  • Kolla - Provides OpenStack service containers and deployment tooling for operating OpenStack clouds.
  • Kuryr - Provides bridges between container networking/storage framework models and OpenStack infrastructure services.
  • Magnum - Provides containers as a service for OpenStack.
  • Murano - Provides an Application Catalog service for OpenStack including support for Kubernetes itself, and for containerized applications, managed by Kubernetes.

There are also a number of example templates available to assist with using the OpenStack Orchestration service (Heat) to deploy and configure either Kubernetes itself or offerings built around Kubernetes such as OpenShift. While each of these approaches has their own pros and cons the common theme is the ability, or potential ability, to use Kubernetes and where available leverage deeper integration between it and the OpenStack services themselves. 

Current SIG participants represent a broad array of organizations including but not limited to: CoreOS, eBay, GoDaddy, Google, IBM, Intel, Mirantis, OpenStack Foundation, Rackspace, Red Hat, Romana, Solinea, VMware. 

The SIG is currently working on collating information about these approaches to help Kubernetes users navigate the OpenStack ecosystem along with feedback on which approaches to the requirements presented work best for operators. 

Kubernetes at OpenStack Summit Austin

The OpenStack Summit is in Austin from April 25th to 29th and is packed with sessions related to containers and container management using Kubernetes. If you plan on joining us in Austin you can review the schedule online where you will find a number of sessions, both in the form of presentations and hands on workshops, relating to Kubernetes and containerization at large. Folks from the Kubernetes OpenStack SIG are particularly keen to get the thoughts of operators in the “Ops: Containers on OpenStack” and “Ops: OpenStack in Containers” working sessions.

Kubernetes community experts will also be on hand in the Container Expert Lounge to answer your burning questions. You can find the lounge on the 4th floor of the Austin Convention Center.

Follow @kubernetesio and #OpenStackSummit to keep up with the latest updates on Kubernetes at OpenStack Summit throughout the week.

Connect With Us

If you’re interested in Kubernetes and OpenStack, there are several ways to participate:

– Steve Gordon, Principal Product Manager at Red Hat, and Ihor Dvoretskyi, OpenStack Operations Engineer at Mirantis

SIG-UI: the place for building awesome user interfaces for Kubernetes

April 20 2016

Editor’s note: This week we’re featuring Kubernetes Special Interest Groups; Today’s post is by the SIG-UI team describing their mission and showing the cool projects they work on.

Kubernetes has been handling production workloads for a long time now (see case studies). It runs on public, private and hybrid clouds as well as bare metal. It can handle all types of workloads (web serving, batch and mixed) and enable zero-downtime rolling updates. It abstracts service discovery, load balancing and storage so that applications running on Kubernetes aren’t restricted to a specific cloud provider or environment.

The abundance of features that Kubernetes offers is fantastic, but implementing a user-friendly, easy-to-use user interface is quite challenging. How shall all the features be presented to users? How can we gradually expose the Kubernetes concepts to newcomers, while empowering experts? There are lots of other challenges like these that we’d like to solve. This is why we created a special interest group for Kubernetes user interfaces.

Meet SIG-UI: the place for building awesome user interfaces for Kubernetes
The SIG UI mission is simple: we want to radically improve the user experience of all Kubernetes graphical user interfaces. Our goal is to craft UIs that are used by devs, ops and resource managers across their various environments, that are simultaneously intuitive enough for newcomers to Kubernetes to understand and use.

SIG UI members have been independently working on a variety of UIs for Kubernetes. So far, the projects we’ve seen have been either custom internal tools coupled to their company workflows, or specialized API frontends. We have realized that there is a need for a universal UI that can be used standalone or be a standard base for custom vendors. That’s how we started the Dashboard UI project. Version 1.0 has been recently released and is included with Kubernetes as a cluster addon. The Dashboard project was recently featured in a talk at KubeCon EU, and we have ambitious plans for the future!

Dashboard UI v1.0 home screen showing applications running in a Kubernetes cluster.

Since the initial release of the Dashboard UI we have been thinking hard about what to do next and what users of UIs for Kubernetes think about our plans. We’ve had many internal discussions on this topic, but most importantly, reached out directly to our users. We created a questionnaire asking a few demographic questions as well as questions for prioritizing use cases. We received more than 200 responses from a wide spectrum of user types, which in turn helped to shape the Dashboard UI’s current roadmap. Our members from LiveWyer summarised the results in a nice infographic

Connect with us

We believe that collaboration is the key to SIG UI success, so we invite everyone to connect with us. Whether you’re a Kubernetes user who wants to provide feedback, develop your own UIs, or simply want to collaborate on the Dashboard UI project, feel free to get in touch. There are many ways you can contact us:

– Piotr Bryk, Software Engineer, Google

SIG-ClusterOps: Promote operability and interoperability of Kubernetes clusters

April 19 2016

Editor’s note: This week we’re featuring Kubernetes Special Interest Groups; Today’s post is by the SIG-ClusterOps team whose mission is to promote operability and interoperability of Kubernetes clusters – to listen, help & escalate.

We think Kubernetes is an awesome way to run applications at scale! Unfortunately, there’s a bootstrapping problem: we need good ways to build secure & reliable scale environments around Kubernetes. While some parts of the platform administration leverage the platform (cool!), there are fundamental operational topics that need to be addressed and questions (like upgrade and conformance) that need to be answered.

Enter Cluster Ops SIG – the community members who work under the platform to keep it running.

Our objective for Cluster Ops is to be a person-to-person community first, and a source of opinions, documentation, tests and scripts second. That means we dedicate significant time and attention to simply comparing notes about what is working and discussing real operations. Those interactions give us data to form opinions. It also means we can use real-world experiences to inform the project.

We aim to become the forum for operational review and feedback about the project. For Kubernetes to succeed, operators need to have a significant voice in the project by weekly participation and collecting survey data. We’re not trying to create a single opinion about ops, but we do want to create a coordinated resource for collecting operational feedback for the project. As a single recognized group, operators are more accessible and have a bigger impact.

What about real world deliverables?

We’ve got plans for tangible results too. We’re already driving toward concrete deliverables like reference architectures, tool catalogs, community deployment notes and conformance testing. Cluster Ops wants to become the clearing house for operational resources. We’re going to do it based on real world experience and battle tested deployments.

Connect with us.

Cluster Ops can be hard work – don’t do it alone. We’re here to listen, to help when we can and escalate when we can’t. Join the conversation at:

The Cluster Ops Special Interest Group meets weekly at 13:00PT on Thursdays, you can join us via the video hangout and see latest meeting notes for agendas and topics covered.

–Rob Hirschfeld, CEO, RackN 

SIG-Networking: Kubernetes Network Policy APIs Coming in 1.3

April 18 2016

Editor’s note: This week we’re featuring Kubernetes Special Interest Groups; Today’s post is by the Network-SIG team describing network policy APIs coming in 1.3 - policies for security, isolation and multi-tenancy.

The Kubernetes network SIG has been meeting regularly since late last year to work on bringing network policy to Kubernetes and we’re starting to see the results of this effort.

One problem many users have is that the open access network policy of Kubernetes is not suitable for applications that need more precise control over the traffic that accesses a pod or service. Today, this could be a multi-tier application where traffic is only allowed from a tier’s neighbor. But as new Cloud Native applications are built by composing microservices, the ability to control traffic as it flows among these services becomes even more critical.

In most IaaS environments (both public and private) this kind of control is provided by allowing VMs to join a ‘security group’ where traffic to members of the group is defined by a network policy or Access Control List (ACL) and enforced by a network packet filter.

The Network SIG started the effort by identifying specific use case scenarios that require basic network isolation for enhanced security. Getting the API right for these simple and common use cases is important because they are also the basis for the more sophisticated network policies necessary for multi-tenancy within Kubernetes.

From these scenarios several possible approaches were considered and a minimal policy specification was defined. The basic idea is that if isolation were enabled on a per namespace basis, then specific pods would be selected where specific traffic types would be allowed.

The simplest way to quickly support this experimental API is in the form of a ThirdPartyResource extension to the API Server, which is possible today in Kubernetes 1.2.

If you’re not familiar with how this works, the Kubernetes API can be extended by defining ThirdPartyResources that create a new API endpoint at a specified URL.


kind: ThirdPartyResource

apiVersion: extensions/v1beta1


  name: network-policy.net.alpha.kubernetes.io

description: "Network policy specification"


- name: v1alpha1
$kubectl create -f third-party-res-def.yaml

This will create an API endpoint (one for each namespace):


Third party network controllers can now listen on these endpoints and react as necessary when resources are created, modified or deleted. Note: With the upcoming release of Kubernetes 1.3 - when the Network Policy API is released in beta form - there will be no need to create a ThirdPartyResource API endpoint as shown above. 

Network isolation is off by default so that all pods can communicate as they normally do. However, it’s important to know that once network isolation is enabled, all traffic to all pods, in all namespaces is blocked, which means that enabling isolation is going to change the behavior of your pods

Network isolation is enabled by defining the network-isolation annotation on namespaces as shown below:

net.alpha.kubernetes.io/network-isolation: [on | off]

Once network isolation is enabled, explicit network policies must be applied to enable pod communication.

A policy specification can be applied to a namespace to define the details of the policy as shown below:

POST /apis/net.alpha.kubernetes.io/v1alpha1/namespaces/tenant-a/networkpolicys/


"kind": "NetworkPolicy",

"metadata": {

"name": "pol1"


"spec": {

"allowIncoming": {

"from": [

{ "pods": { "segment": "frontend" } }


"toPorts": [

{ "port": 80, "protocol": "TCP" }



"podSelector": { "segment": "backend" }



In this example, the ‘ tenant-a ’ namespace would get policy ‘ pol1 ’ applied as indicated. Specifically, pods with the segment label ‘ backend ’ would allow TCP traffic on port 80 from pods with the segment label ‘ frontend ’ to be received.

Today, Romana, OpenShift, OpenContrail and Calico support network policies applied to namespaces and pods. Cisco and VMware are working on implementations as well. Both Romana and Calico demonstrated these capabilities with Kubernetes 1.2 recently at KubeCon. You can watch their presentations here: Romana (slides), Calico (slides). 

How does it work?

Each solution has their their own specific implementation details. Today, they rely on some kind of on-host enforcement mechanism, but future implementations could also be built that apply policy on a hypervisor, or even directly by the network itself. 

External policy control software (specifics vary across implementations) will watch the new API endpoint for pods being created and/or new policies being applied. When an event occurs that requires policy configuration, the listener will recognize the change and a controller will respond by configuring the interface and applying the policy.  The diagram below shows an API listener and policy controller responding to updates by applying a network policy locally via a host agent. The network interface on the pods is configured by a CNI plugin on the host (not shown).


If you’ve been holding back on developing applications with Kubernetes because of network isolation and/or security concerns, these new network policies go a long way to providing the control you need. No need to wait until Kubernetes 1.3 since network policy is available now as an experimental API enabled as a ThirdPartyResource.

If you’re interested in Kubernetes and networking, there are several ways to participate - join us at:

The Networking “Special Interest Group,” which meets bi-weekly at 3pm (15h00) Pacific Time at SIG-Networking hangout

–Chris Marino, Co-Founder, Pani Networks

How to deploy secure, auditable, and reproducible Kubernetes clusters on AWS

April 15 2016

Today’s guest post is written by Colin Hom, infrastructure engineer at CoreOS, the company delivering Google’s Infrastructure for Everyone Else (#GIFEE) and running the world’s containers securely on CoreOS Linux, Tectonic and Quay.

Join us at CoreOS Fest Berlin, the Open Source Distributed Systems Conference, and learn more about CoreOS and Kubernetes.

At CoreOS, we’re all about deploying Kubernetes in production at scale. Today we are excited to share a tool that makes deploying Kubernetes on Amazon Web Services (AWS) a breeze. Kube-aws is a tool for deploying auditable and reproducible Kubernetes clusters to AWS, currently used by CoreOS to spin up production clusters.

Today you might be putting the Kubernetes components together in a more manual way. With this helpful tool, Kubernetes is delivered in a streamlined package to save time, minimize interdependencies and quickly create production-ready deployments.

A simple templating system is leveraged to generate cluster configuration as a set of declarative configuration templates that can be version controlled, audited and re-deployed. Since the entirety of the provisioning is by AWS CloudFormation and cloud-init, there’s no need for external configuration management tools on your end. Batteries included!

To skip the talk and go straight to the project, check out the latest release of kube-aws, which supports Kubernetes 1.2.x. To get your cluster running, check out the documentation.

Why kube-aws? Security, auditability and reproducibility

Kube-aws is designed with three central goals in mind.

Secure : TLS assets are encrypted via the AWS Key Management Service (KMS) before being embedded in the CloudFormation JSON. By managing IAM policy for the KMS key independently, an operator can decouple operational access to the CloudFormation stack from access to the TLS secrets.

Auditable : kube-aws is built around the concept of cluster assets. These configuration and credential assets represent the complete description of the cluster. Since KMS is used to encrypt TLS assets, you can feel free to check your unencrypted stack JSON into version control as well!

Reproducible : The –export option packs your parameterized cluster definition into a single JSON file which defines a CloudFormation stack. This file can be version controlled and submitted directly to the CloudFormation API via existing deployment tooling, if desired.

How to get started with kube-aws

On top of this foundation, kube-aws implements features that make Kubernetes deployments on AWS easier to manage and more flexible. Here are some examples.

Route53 Integration : Kube-aws can manage your cluster DNS records as part of the provisioning process.


externalDNSName: my-cluster.kubernetes.coreos.com

createRecordSet: true

hostedZone: kubernetes.coreos.com

recordSetTTL: 300

Existing VPC Support : Deploy your cluster to an existing VPC.


vpcId: vpc-xxxxx

routeTableId: rtb-xxxxx

Validation : Kube-aws supports validation of cloud-init and CloudFormation definitions, along with any external resources that the cluster stack will integrate with. For example, here’s a cloud-config with a misspelled parameter:




    interrface: $private\_ipv4  

$ kube-aws validate

> Validating UserData…
Error: cloud-config validation errors:
UserDataWorker: line 4: warning: unrecognized key “interrface”

To get started, check out the kube-aws documentation.

Future Work

As always, the goal with kube-aws is to make deployments that are production ready. While we use kube-aws in production on AWS today, this project is pre-1.0 and there are a number of areas in which kube-aws needs to evolve.

Fault tolerance : At CoreOS we believe Kubernetes on AWS is a potent platform for fault-tolerant and self-healing deployments. In the upcoming weeks, kube-aws will be rising to a new challenge: surviving the Chaos Monkey – control plane and all!

Zero-downtime updates : Updating CoreOS nodes and Kubernetes components can be done without downtime and without interdependency with the correct instance replacement strategy.

A github issue tracks the work towards this goal. We look forward to seeing you get involved with the project by filing issues or contributing directly.

Learn more about Kubernetes and meet the community at CoreOS Fest Berlin - May 9-10, 2016

– Colin Hom, infrastructure engineer, CoreOS

Container survey results - March 2016

April 08 2016

Last month, we had our third installment of our container survey and today we look at the results.  (raw data is available here)

Looking at the headline number, “how many people are using containers” we see a decrease in the number of people currently using containers from 89% to 80%.  Obviously, we can’t be certain for the cause of this decrease, but it’s my believe that the previous number was artificially high due to sampling biases and we did a better job getting a broader reach of participants in the March survey and so the March numbers more accurately represent what is going on in the world.

Along the lines of getting an unbiased sample, I’m excited to announce that going forward, we will be partnering with The New Stack and theCloud Native Compute Foundation to publicize and distribute this container survey.  This partnership will enable us to reach a broader audience than we are reaching and thus obtain a significantly more unbiased sample and representative portrayal of current container usage.  I’m really excited about this collaboration!

But without further ado, more on the data.

For the rest of the numbers, the March survey shows steady continuation of the numbers that we saw in February.  Most of the container usage is still in Development and Testing, though a solid majority (60%) are using it for production as well.  For the remaining folks using containers there continues to be a plan to bring containers to production as the “I am planning to” number for production use matches up nearly identically with the numbers for people currently in testing.

Physical and virtual machines continue to be the most popular places to deploy containers, though the March survey shows a fairly substantial drop (48% -> 35%) in people deploying to physical machines.

Likewise hosted container services show growth, with nearly every service showing some growth.  Google Container Engine continues to be the most popular in the survey, followed by the Amazon EC2 Container Service.  It will be interesting to see how those numbers change as we move to the New Stack survey.

Finally, Kubernetes is still the favorite for container manager, with Bash scripts are still in second place.  As with the container service provider numbers I’ll be quite interested to see what this looks like with a broader sample set.

Finally, the absolute use of containers appears to be ticking up.  The number of people running more than 250 containers has grown from 12% to nearly 20%.  And the number people running containers on 50 or more machines has grown from 10% to 18%.

As always, the raw data is available for you to analyze here.

–Brendan Burns, Software Engineer, Google

Adding Support for Kubernetes in Rancher

April 08 2016

Today’s guest post is written by Darren Shepherd, Chief Architect at Rancher Labs, an open-source software platform for managing containers.

Over the last year, we’ve seen a tremendous increase in the number of companies looking to leverage containers in their software development and IT organizations. To achieve this, organizations have been looking at how to build a centralized container management capability that will make it simple for users to get access to containers, while centralizing visibility and control with the IT organization. In 2014 we started the open-source Rancher project to address this by building a management platform for containers.

Recently we shipped Rancher v1.0. With this latest release, Rancher, an open-source software platform for managing containers, now supports Kubernetes as a container orchestration framework when creating environments. Now, launching a Kubernetes environment with Rancher is fully automated, delivering a functioning cluster in just 5-10 minutes. 

We created Rancher to provide organizations with a complete management platform for containers. As part of that, we’ve always supported deploying Docker environments natively using the Docker API and Docker Compose. Since its inception, we’ve been impressed with the operational maturity of Kubernetes, and with this release, we’re making it possible to deploy a variety of container orchestration and scheduling frameworks within the same management platform.

Adding Kubernetes gives users access to one of the fastest growing platforms for deploying and managing containers in production. We’ll provide first-class Kubernetes support in Rancher going forward and continue to support native Docker deployments. 

Bringing Kubernetes to Rancher

Kubernetes deployment-3.PNG

Our platform was already extensible for a variety of different packaging formats, so we were optimistic about embracing Kubernetes. We were right, working with the Kubernetes project has been a fantastic experience as developers. The design of the project made this incredibly easy, and we were able to utilize plugins and extensions to build a distribution of Kubernetes that leveraged our infrastructure and application services. For instance, we were able to plug in Rancher’s software defined networking, storage management, load balancing, DNS and infrastructure management functions directly into Kubernetes, without even changing the code base.

Even better, we have been able to add a number of services around the core Kubernetes functionality. For instance, we implemented our popular application catalog on top of Kubernetes. Historically we’ve used Docker Compose to define application templates, but with this release, we now support Kubernetes services, replication controllers and pods to deploy applications. With the catalog, users connect to a git repo and automate deployment and upgrade of an application deployed as Kubernetes services. Users then configure and deploy a complex multi-node enterprise application with one click of a button. Upgrades are fully automated as well, and pushed out centrally to users.

Giving Back

Like Kubernetes, Rancher is an open-source software project, free to use by anyone, and given to the community without any restrictions. You can find all of the source code, upcoming releases and issues for Rancher on GitHub. We’re thrilled to be joining the Kubernetes community, and look forward to working with all of the other contributors. View a demo of the new Kubernetes support in Rancher here

– Darren Shepherd, Chief Architect, Rancher Labs

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