Production-Grade Container Orchestration

Note: This section links to third party projects that provide functionality required by Kubernetes. The Kubernetes project authors aren't responsible for these projects, which are listed alphabetically. To add a project to this list, read the content guide before submitting a change. More information. Add-ons extend the functionality of Kubernetes. This page lists some of the available add-ons and links to their respective installation instructions. The list does not try to be exhaustive.

Networking is a central part of Kubernetes, but it can be challenging to understand exactly how it is expected to work. There are 4 distinct networking problems to address: Highly-coupled container-to-container communications: this is solved by Pods and localhost communications. Pod-to-Pod communications: this is the primary focus of this document. Pod-to-Service communications: this is covered by Services. External-to-Service communications: this is also covered by Services. Kubernetes is all about sharing machines among applications.

System component metrics can give a better look into what is happening inside them. Metrics are particularly useful for building dashboards and alerts. Kubernetes components emit metrics in Prometheus format. This format is structured plain text, designed so that people and machines can both read it. Metrics in Kubernetes In most cases metrics are available on /metrics endpoint of the HTTP server. For components that don't expose endpoint by default, it can be enabled using --bind-address flag.

Production-Grade Container Orchestration

The aggregation layer allows Kubernetes to be extended with additional APIs, beyond what is offered by the core Kubernetes APIs. The additional APIs can either be ready-made solutions such as a metrics server, or APIs that you develop yourself. The aggregation layer is different from Custom Resource Definitions, which are a way to make the kube-apiserver recognise new kinds of object. Aggregation layer The aggregation layer runs in-process with the kube-apiserver.

Operators are software extensions to Kubernetes that make use of custom resources to manage applications and their components. Operators follow Kubernetes principles, notably the control loop. Motivation The operator pattern aims to capture the key aim of a human operator who is managing a service or set of services. Human operators who look after specific applications and services have deep knowledge of how the system ought to behave, how to deploy it, and how to react if there are problems.

This page shows how to use Romana for NetworkPolicy. Before you begin Complete steps 1, 2, and 3 of the kubeadm getting started guide. Installing Romana with kubeadm Follow the containerized installation guide for kubeadm. Applying network policies To apply network policies use one of the following: Romana network policies. Example of Romana network policy. The NetworkPolicy API. What's next Once you have installed Romana, you can follow the Declare Network Policy to try out Kubernetes NetworkPolicy.

The kubectl command-line tool supports several different ways to create and manage Kubernetes objects. This document provides an overview of the different approaches. Read the Kubectl book for details of managing objects by Kubectl. Management techniques Warning:A Kubernetes object should be managed using only one technique. Mixing and matching techniques for the same object results in undefined behavior. Management technique Operates on Recommended environment Supported writers Learning curve Imperative commands Live objects Development projects 1+ Lowest Imperative object configuration Individual files Production projects 1 Moderate Declarative object configuration Directories of files Production projects 1+ Highest Imperative commands When using imperative commands, a user operates directly on live objects in a cluster.

An overview of the key components that make up a Kubernetes cluster.