1. Origins Originally, two CoreOS employees, in order to make deploying etcd clusters easier, bound corresponding logical operations to the create, delete, and update events of the etcdCluster object, using Kubernetes to automate etcd cluster management. A few months later, at a KubeCon conference, they shared this approach, which they called Operator, and it received a strong response from the community.

1. Why Helm Is Needed One important design philosophy in Kubernetes is declarative operation. Users change the system by setting the system’s expected state. For example, the current replica count is 2 and it needs to be adjusted to 3. The declarative way is to modify the replica count in

Four or five years have passed since I first started blogging. My original intent was to record, think, and organize — a little more for my own benefit, and if it could help others too, so much the better. I went from csdn at the very beginning, to deploying Ghost on Linode, to Pages hosting, and finally to settling on a CDN.

1. What Is kubectl kubectl is the command-line tool for Kubernetes. It interacts with the cluster through the API server. 2. Configuring kubectl kubectl can be configured through ~/.kube/config to connect to one or more clusters. For details on how to configure it, see: Configure Access to Multiple Clusters. If you need to configure a remote cluster, see: Building a Remote Kubernetes Development Environment.

1. Cluster 1.1 Master The Master is responsible for managing and maintaining Kubernetes cluster information, dispatching tasks to Nodes, and receiving feedback. The components running on the Master include kube-apiserver, kube-scheduler, kube-controller-manager, cloud-controller-manager, and so on. 1.2 Node A Node carries the cluster workload; it can be a physical machine or a virtual machine.