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SIG Cluster Lifecycle Update

Lucas Käldström & Robert Bailey�6th December 2017 - KubeCon Austin

Abstract:

The Cluster Lifecycle SIG is the Special Interest Group that is responsible for building the user experience for deploying and upgrading Kubernetes clusters. Since splitting out of SIG Cluster Ops in mid-2016 we have primarily focused on creating kubeadm, a streamlined installer tool and building block to simplify the installation and upgrade experience. We have recently begun building a Cluster API to provide an abstraction of machines across different deployment environments along with a common control plane configuration.

In this update session we will present the SIG's mission statement, review recent accomplishments, and discuss our future plans, where you are very welcome to contribute to the discussion. We will also focus on how new contributors can get involved in helping shape the future of Kubernetes cluster lifecycle management.

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Who’s on stage?

Lucas Käldström

SIG Cluster Lifecycle co-lead

CNCF Ambassador & CKA

Contractor for Weaveworks

Upper Secondary School Student

Robert Bailey

SIG Cluster Lifecycle co-lead

Founding member of GKE

Googler

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Our Mission

SIG Cluster Lifecycle examines how we should change Kubernetes to make it easier to operate.

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What we do

Control Plane Installation Management

"How do I run the Kubernetes control plane?"
Building kubeadm, cleaning up outdated getting started guides and improving docs��

Control Plane Configuration Management

"How do I configure the Kubernetes control plane?"
Published guidelines for Component Configuration and building a Control Plane API

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What we do

Simplifying Infrastructure Management

“How do I set up my network / machines?”
Working on a Machines API as part of the Cluster API��

Addon Management

“How do I install things outside the core control plane?”
Many different approaches used today; still working on a plan for convergence

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Cluster API

A declarative way to create, configure, and manage a cluster

apiVersion: "cluster-api.k8s.io/v1alpha1"
kind: Cluster�

Controllers will reconcile desired vs. actual state

These could run inside or outside the cluster�

Cloud Providers will implement support for their IaaS

GCE, AWS, Azure, Digital Ocean, Terraform and Docker Machine, etc.�

Port existing tools to target Cluster API

Cluster upgrades, auto repair, cluster autoscaler

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What is kubeadm and why should I care?

= A tool that sets up a minimum viable, best-practice Kubernetes cluster

Master A

Master N*

Node 1

Node N

kubeadm

Cloud Provider

Load Balancers

Monitoring

Logging

Cluster API Spec

Cluster API

Cluster API Implementation

Addons API*

Kubernetes API

Bootstrapping

Machines

Infrastructure

Layer 2

Layer 3

Layer 1

*=Yet to be done/WIP

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kubeadm vs kops

Two different projects, two different scopes

kops

Master A

Master N*

Node 1

Node N

kubeadm

Cloud Provider

Load Balancers

Monitoring

Logging

Cluster API Spec

Cluster API Implementation

Addons API*

Kubernetes API

Bootstrapping

Machines

Infrastructure

Cluster API

*=Yet to be done/WIP

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Key design takeaways

kubeadm’s task is to set up a best-practice cluster for each minor version
The user experience should be simple, and the cluster reasonably secure
kubeadm’s scope is limited; intended to be a building block

Only ever deals with the local filesystem and the Kubernetes API
Agnostic to how exactly the kubelet is run
Setting up or favoring a specific CNI network is out of scope

Composable architecture with everything divided into phases

Audience: build-your-first-own-cluster users & higher-level tools like kops & kubicorn

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Recent accomplishments

kubeadm v1.8

`kubeadm upgrade`
Alpha support for self-hosting
Extensibility work with phases and `kubeadm alpha phase`
kubeadm adoption work; e.g. kubespray�

kubeadm v1.9

Alpha support for CoreDNS and IPv6
Alpha ComponentConfig for the managing the kubelet and kube-proxy�

An alpha Cluster API and prototype implementation

Initial spec and GCE implementation

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A sneak-peak into our plans for 2018

Productionize tools currently under development

kubeadm to GA
Beta or higher Cluster API and implementations
Component Configuration for all critical system components�

Better documentation

Recommended cluster parameters
Highly Available cluster deployments
External dependencies
Create a tool-less starting from scratch installation guide�

Addons API

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How can you contribute to our SIG?

Relevant release cycle doc → turn into a fully-featured contributing-to-the-SIG doc

We’re working on growing the contributor/reviewers pool; scaling the SIG

Rebranding the kubeadm meetings on Weds as SIG Office Hours?

Attend our meetings / be around on Slack

Look at our backlog of prioritized kubeadm issues

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Relevant KubeCon talks

Robert and Kris are giving a session on Thursday at 11:10am on the Cluster API
Lucas is giving a kubeadm Deep Dive session on Thursday at 4:35pm
Diego is giving a talk on self-hosting on Friday at 2:45pm

We are hosting a SIG meetup on Thursday at 5:30pm at the Austin Taco Project (basement of the Hilton Hotel)

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What now?

Follow the SIG Cluster Lifecycle YouTube playlist

Check out the meeting notes for our weekly SIG meetings in Zoom

Join #sig-cluster-lifecycle (for dev) and #kubeadm (for support)

Prep for and take the Certified Kubernetes Administrator exam

Read the two latest SIG updates on the Kubernetes blog in January and August

Check out the kubeadm setup guide, reference doc and design doc

Read how you can get involved and improve kubeadm!

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Thank you!

@roberthbailey & @luxas on Github

@roberthbailey & @kubernetesonarm on Twitter�robertbailey@google.com / lucas@luxaslabs.com