Pluggability is part of the success story of Kubernetes, and as a community we have ensured that many layers – including storage, networking, and schedulers – can be replaced and improved without changing the Kubernetes user experience. Earlier this year, the Kubernetes project created an API called the Container Runtime Interface (CRI) to make the way a container is run on Kubernetes pluggable.
A reliable key-value store gives distributed systems a common substrate for consistent configuration and coordination. One such system is the etcd project, an open source key-value store created by CoreOS. It is the heart of many production distributed systems and is the data store for Kubernetes, among other projects.
Here at CoreOS, we're always working along with the open source community to improve and enhance etcd, a distributed key-value store created by CoreOS. For the upcoming etcd 3.3 series, one of the challenges we're tackling is improving the performance and resiliency of linearizable reads using a distributed systems technique known as leasing.
A new API object type called a Custom Resource Definition (CRD) will replace the existing Third Party Resource (TPR) extension mechanism over the next two Kubernetes releases. In the upcoming Kubernetes version 1.7, CRDs are introduced into the beta API namespace for features designated for official support. By version 1.8, CRDs will be the supported mechanism and TPRs will be entirely deprecated.
The etcd team is pleased to announce etcd 3.2.0, the latest feature release in the 3.x series. This edition has proxy improvements, boosted backend concurrency, distributed coordination services, a slimmer Go client, JWT authentication, and more.
kubectl enables system administrators to interact with Kubernetes using a well-designed command-line interface. The common interactions include running services, grabbing pod logs, or identifying nodes inside of a cluster. For most Kubernetes users, these interactions are second nature.
Prometheus is a monitoring system and time series database expressly designed for the highly distributed, automated, and scalable modern cluster architectures orchestrated by systems like Kubernetes. Prometheus has an operational model and a query language tailored for distributed, dynamic environments.
Distributed systems commonly rely on a distributed consensus to coordinate work. Usually the systems providing distributed consensus guarantee information is delivered in order and never suffer split-brain conflicts.
While Kubernetes is ushering in a world where SSH is less necessary on a daily basis for deploying and managing applications, there are still instances when SSH is necessary for gathering statistics, debugging issues, and repairing configuration issues. So, while years from now there may not be a need to SSH and run one-off debugging sessions, the tools below are useful for quickly SSH'ing into machines in your Kubernetes cluster.