![what is kubernetes master what is kubernetes master](https://dzone.com/storage/temp/8742780-kubernetes-architecture.png)
All API clients should be authenticated in order to interact with the API Server.
![what is kubernetes master what is kubernetes master](https://digitalvarys.com/wp-content/uploads/2019/05/Kubernetes-Cluster-with-ansible.png)
The API Server is also responsible for the authentication and authorization mechanism. The API Server is the only Kubernetes component that connects to etcd all the other components must go through the API Server to work with the cluster state. The API Server serves up the Kubernetes API and is intended to be a relatively simple server, with most business logic implemented in separate components or in plugins. In short, it processes REST operations, validates them, and updates the corresponding objects in etcd. The API Server is the main management point of the entire cluster. When you interact with your Kubernetes cluster using the kubectl command-line interface, you are actually communicating with the master API Server component. This is a crucial feature in the context of Kubernetes, as the API Server component heavily relies on this to get notified and call the appropriate business logic components to move the current state towards the desired state. Once a key is changed, its “watchers” get notified. Įtcd also implements a watch feature, which provides an event-based interface for asynchronously monitoring changes to keys.
![what is kubernetes master what is kubernetes master](https://i0.wp.com/tennexas.com/wp-content/uploads/2020/06/12Deployment.png)
You can play online with a 5-node etcd cluster at. It can be used to perform a variety of actions, such as: For further information, please read the Raft paper.Įtcdctl is the command-line interface tool written in Go that allows manipulating an etcd cluster. Raft defines three different roles (Leader, Follower, and Candidate) and achieves consensus via an elected leader. The Consensus problem involves multiple servers agreeing on values a common problem that arises in the context of replicated state machines. Raft is a consensus algorithm designed as an alternative to Paxos. In case you are running Kubernetes on AWS, you can also back up etcd by taking a snapshot of the EBS volume.Įtcd is written in Go and uses the Raft consensus algorithm to manage a highly-available replicated log. You can easily back up your etcd data using the etcdctl snapshot save command. When it comes to Kubernetes, etcd reliably stores the configuration data of the Kubernetes cluster, representing the state of the cluster (what nodes exist in the cluster, what pods should be running, which nodes they are running on, and a whole lot more) at any given point of time.Īs all cluster data is stored in etcd, you should always have a backup plan for it. EtcdĮtcd is a distributed, consistent key-value store used for configuration management, service discovery, and coordinating distributed work.
#WHAT IS KUBERNETES MASTER HOW TO#
See how to build high-Availability clusters official guides for further information. In production, you should set up Kubernetes with multiple masters for high availability. Essentially, it’s the brain of the cluster! Now, let’s dive into each master component. The Kubernetes master runs the Scheduler, Controller Manager, API Server and etcd components and is responsible for managing the Kubernetes cluster. I’m pretty sure that by the end of this article you will have a clear understanding of how these components interact with each other. Well, this might look complicated at first glance, but actually, it’s not so much.