This guide is for people who want to craft a custom Kubernetes cluster. If you can find an existing Getting Started Guide that meets your needs on this list, then we recommend using it, as you will be able to benefit from the experience of others. However, if you have specific IaaS, networking, configuration management, or operating system requirements not met by any of those guides, then this guide will provide an outline of the steps you need to take. Note that it requires considerably more effort than using one of the pre-defined guides.
This guide is also useful for those wanting to understand at a high level some of the steps that existing cluster setup scripts are making.
MetalLB is a load-balancer implementation for bare metal Kubernetes clusters, using standard routing protocols.
Why?
Kubernetes does not offer an implementation of network load-balancers (Services of type LoadBalancer) for bare metal clusters. The implementations of Network LB that Kubernetes does ship with are all glue code that calls out to various IaaS platforms (GCP, AWS, Azure…). If you’re not running on a supported IaaS platform (GCP, AWS, Azure…), LoadBalancers will remain in the “pending” state indefinitely when created.
Bare metal cluster operators are left with two lesser tools to bring user traffic into their clusters, “NodePort” and “externalIPs” services. Both of these options have significant downsides for production use, which makes bare metal clusters second class citizens in the Kubernetes ecosystem.
MetalLB aims to redress this imbalance by offering a Network LB implementation that integrates with standard network equipment, so that external services on bare metal clusters also “just work” as much as possible.
This page explains two different approaches to setting up a highly available Kubernetes cluster using kubeadm:
With stacked masters. This approach requires less infrastructure. etcd members and control plane nodes are co-located.
With an external etcd cluster. This approach requires more infrastructure. The control plane nodes and etcd members are separated.
Your clusters must run Kubernetes version 1.11 or later. You should also be aware that setting up HA clusters with kubeadm is still experimental. You might encounter issues with upgrading your clusters, for example. We encourage you to try either approach, and provide feedback.
Traditional SDNs are complex, making them hard to deploy and troubleshoot. Calico removes that complexity, with a simplified networking model designed for the demands of today's cloud-native applications.
Unlike SDNs that require a central controller, limiting scalability, Calico is built on a fully distributed, scale-out architecture. So it scales smoothly from a single developer laptop to large enterprise deployments.
Defining secure network policy used to be reserved for skilled network engineers. Calico's powerful micro-segmentation capabilities build on a simple policy language that naturally expresses the developer's intent.
Ark gives you tools to back up and restore your Kubernetes cluster resources and persistent volumes. Ark lets you:
Take backups of your cluster and restore in case of loss.
Copy cluster resources across cloud providers. NOTE: Cloud volume migrations are not yet supported.
Replicate your production environment for development and testing environments.
Ark consists of:
A server that runs on your cluster
A command-line client that runs locallyHeptio Sonobuoy is a diagnostic tool that makes it easier to understand the state of a Kubernetes cluster by running a set of Kubernetes conformance tests in an accessible and non-destructive manner. It is a customizable, extendable, and cluster-agnostic way to generate clear, informative reports about your cluster.
Its selective data dumps of Kubernetes resource objects and cluster nodes allow for the following use cases:
Integrated end-to-end (e2e) conformance-testing
Workload debugging
Custom data collection via extensible plugins
Sonobuoy supports Kubernetes versions 1.9 and later.
Kubernetes is an open-source system for automating deployment, scaling, and management of containerized applications.
It groups containers that make up an application into logical units for easy management and discovery. Kubernetes builds upon 15 years of experience of running production workloads at Google, combined with best-of-breed ideas and practices from the community.
Add-ons extend the functionality of Kubernetes.
This page lists some of the available add-ons and links to their respective installation instructions.
Add-ons in each section are sorted alphabetically - the ordering does not imply any preferential status.
kubeadm helps you bootstrap a minimum viable Kubernetes cluster that conforms to best practices. With kubeadm, your cluster should pass Kubernetes Conformance tests. Kubeadm also supports other cluster lifecycle functions, such as upgrades, downgrade, and managing bootstrap tokens.
Because you can install kubeadm on various types of machine (e.g. laptop, server, Raspberry Pi, etc.), it’s well suited for integration with provisioning systems such as Terraform or Ansible.
kubeadm’s simplicity means it can serve a wide range of use cases:
New users can start with kubeadm to try Kubernetes out for the first time.
Users familiar with Kubernetes can spin up clusters with kubeadm and test their applications.
Larger projects can include kubeadm as a building block in a more complex system that can also include other installer tools.
kubeadm is designed to be a simple way for new users to start trying Kubernetes out, possibly for the first time, a way for existing users to test their application on and stitch together a cluster easily, and also to be a building block in other ecosystem and/or installer tool with a larger scope.
You can install kubeadm very easily on operating systems that support installing deb or rpm packages. The responsible SIG for kubeadm, SIG Cluster Lifecycle, provides these packages pre-built for you, but you may also on other OSes.
"n. person responsible for scrubbing a ship's deck."
Deckschrubber inspects images of a Docker Registry and removes those older than a given age.
This blog offers some guidelines for running a production grade Kubernetes cluster in an environment like an on-premise data center or edge location.
What does it mean to be “production grade”?
The installation is secure
The deployment is managed with a repeatable and recorded process
Performance is predictable and consistent
Updates and configuration changes can be safely applied
Logging and monitoring is in place to detect and diagnose failures and resource shortages
Service is “highly available enough” considering available resources, including constraints on money, physical space, power, etc.
A recovery process is available, documented, and tested for use in the event of failures
In short, production grade means anticipating accidents and preparing for recovery with minimal pain and delay.
This article is directed at on-premise Kubernetes deployments on a hypervisor or bare-metal platform, facing finite backing resources compared to the expansibility of the major public clouds. However, some of these recommendations may also be useful in a public cloud if budget constraints limit the resources you choose to consume.
A single node bare-metal Minikube deployment may be cheap and easy, but is not production grade. Conversely, you’re not likely to achieve Google’s Borg experience in a retail store, branch office, or edge location, nor are you likely to need it.
This blog offers some guidance on achieving a production worthy Kubernetes deployment, even when dealing with some resource constraints.
gVisor is a user-space kernel, written in Go, that implements a substantial portion of the Linux system surface. It includes an Open Container Initiative (OCI) runtime called runsc that provides an isolation boundary between the application and the host kernel. The runsc runtime integrates with Docker and Kubernetes, making it simple to run sandboxed containers.
gVisor takes a distinct approach to container sandboxing and makes a different set of technical trade-offs compared to existing sandbox technologies, thus providing new tools and ideas for the container security landscape.
Weave Net - Weaving Containers into Applications
Weave Net creates a virtual network that connects Docker containers across multiple hosts and enables their automatic discovery. With Weave Net, portable microservices-based applications consisting of multiple containers can run anywhere: on one host, multiple hosts or even across cloud providers and data centers. Applications use the network just as if the containers were all plugged into the same network switch, without having to configure port mappings, ambassadors or links.
Services provided by application containers on the weave network can be exposed to the outside world, regardless of where they are running. Similarly, existing internal systems can be opened to accept connections from application containers irrespective of their location.
This first release of Kata Containers completes the merger of Intel’s Clear Containers and Hyper’s runV technologies, and delivers an OCI compatible runtime with seamless integration for container ecosystem technologies like Docker and Kubernetes.
“Cloud native” is a term used to describe applications designed specifically to run on a cloud-
based infrastructure. Typically, cloud-native applications are developed as loosely coupled
microservices running in containers managed by platforms. These applications anticipate
failure, and they run and scale reliably even when their underlying infrastructure is experiencing outages.
To offer such capabilities, cloud-native platforms impose a set of contracts and
constraints on the applications running on them. These contracts ensure that the applications
conform to certain constraints and allow the platforms to automate the management of the
containerized applications. Many organizations understand the necessity and importance of
becoming cloud native, but do not know where to start. Ensuring that cloud-native platforms
and the containerized applications that run on them work seamlessly together provides the
ability to anticipate failure and the reliability to run and scale even when the underlying
infrastructure experiences outages. This whitepaper describes a number of principles that
containerized applications must comply with in order to become good cloud-native citizens.
Adhering to these principles will help ensure that your applications are suitable for
automation in cloud-native platforms such as Kubernetes.
Nachdem die hybride Cloud aus Windows- und Linux-Systemen dank Packer und Vagrant zur Verfügung steht, soll Ansible jetzt einen Docker Swarm automatisiert initialisieren und das Deployment vorbereiten.
Eine hybride Cloud aus Windows- und Linux-Systemen kann kompliziert sein: Docker Swarm und Ansible sind jedoch zwei Tools die dabei helfen können, die Container auch über System- und Servergrenzen hinweg kontrollieren zu können.
Containers are a great solution for consistent software deployments. When you start using containers in your environment, you and your team will quickly realise that you need a system which allows you to automate container operations. You need a system to keep your containers running when stuff breaks (which always happens, expect failure!), be able to scale up and down, and which is also extensible, so you can interact with it or built upon it to get the functionality you need. The most popular system for deploying, scaling and managing containerized applications is Kubernetes.