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

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. Kubectl Basic Commands 1.1 Creating Objects 1 2 3 4 5 6 7 8 # Create resources; a remote URL also works kubectl create -f ./my.yaml # Create resources from multiple files kubectl create -f ./my1.yaml -f ./my2.yaml # Create resources using all manifest files in a directory kubectl create -f .

1. Basic Concepts 1.1 Kubernetes Kubernetes (K8s for short), the successor to Google’s Borg, is an open-source system for automatically deploying, scaling, and managing containerized applications. The features it provides: Automated deployment of containers Automated scaling up and down Automated application/service upgrades Grouping containers to serve traffic externally, with load balancing support Health checks for services, with automatic restarts 1.