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.

FEATURE STATE: Kubernetes v1.30 [stable] Pods were considered ready for scheduling once created. Kubernetes scheduler does its due diligence to find nodes to place all pending Pods. However, in a real-world case, some Pods may stay in a "miss-essential-resources" state for a long period. These Pods actually churn the scheduler (and downstream integrators like Cluster AutoScaler) in an unnecessary manner. By specifying/removing a Pod's .spec.schedulingGates, you can control when a Pod is ready to be considered for scheduling.

The EndpointSlice API is the mechanism that Kubernetes uses to let your Service scale to handle large numbers of backends, and allows the cluster to update its list of healthy backends efficiently.

Production-Grade Container Orchestration

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.

Production-Grade Container Orchestration

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.

This page shows how to access clusters using the Kubernetes API. Before you begin You need to have a Kubernetes cluster, and the kubectl command-line tool must be configured to communicate with your cluster. It is recommended to run this tutorial on a cluster with at least two nodes that are not acting as control plane hosts. If you do not already have a cluster, you can create one by using minikube or you can use one of these Kubernetes playgrounds:

FEATURE STATE: Kubernetes v1.26 [stable] Kubernetes keeps many aspects of how pods execute on nodes abstracted from the user. This is by design. However, some workloads require stronger guarantees in terms of latency and/or performance in order to operate acceptably. The kubelet provides methods to enable more complex workload placement policies while keeping the abstraction free from explicit placement directives. For detailed information on resource management, please refer to the Resource Management for Pods and Containers documentation.

FEATURE STATE: Kubernetes v1.11 [beta] The cloud-controller-manager is a Kubernetes control plane component that embeds cloud-specific control logic. The cloud controller manager lets you link your cluster into your cloud provider's API, and separates out the components that interact with that cloud platform from components that only interact with your cluster. By decoupling the interoperability logic between Kubernetes and the underlying cloud infrastructure, the cloud-controller-manager component enables cloud providers to release features at a different pace compared to the main Kubernetes project.