A Kubernetes cluster is a collection of nodes that run containerized applications, managed by Kubernetes, an open-source container orchestration platform. The cluster consists of two main types of nodes: the control plane (or master nodes) and worker nodes.
Components of a Kubernetes Cluster
Control Plane: This is the central management entity of the cluster, responsible for maintaining the desired state of the cluster, scheduling applications, and managing the overall cluster lifecycle. Key components of the control plane include:
API Server: Exposes the Kubernetes API, serving as the front end of the Kubernetes control plane.
etcd: A distributed key-value store that holds all cluster data.
Scheduler: Assigns workloads to nodes based on resource availability and other constraints.
Controller Manager: Runs various controllers that regulate the state of the cluster, such as node controllers and replication controllers.
Cloud Controller Manager: Integrates with cloud provider APIs to manage cloud-specific resources.
Worker Nodes: These nodes run the actual applications and workloads. Each worker node contains:
Kubelet: An agent that ensures containers are running in a pod as specified.
Kube-proxy: Manages network rules and facilitates communication between pods and services.
Container Runtime: The software responsible for running containers, such as Docker or containerd.
Key Concepts
Pods: The smallest deployable units in Kubernetes, which can contain one or more containers.
Services: Abstractions that define a logical set of pods and a policy by which to access them.
Namespaces: Virtual clusters within a physical cluster, allowing for resource isolation and management.
Functionality
Kubernetes clusters automate the deployment, scaling, and management o...
