Kubernetes Components – What are they?
Kubernetes is a popular open-source container orchestration platform that automates the deployment, scaling, and management of containerized applications. It consists of several components that work together to provide a robust and scalable container orchestration solution.
Key Kubernetes Components
Here are some key Kubernetes components:
Master Components
- kube-apiserver: this component exposes the Kubernetes API and serves as the entry point for all administrative tasks.
- etcd: a distributed key-value store used to store the cluster’s configuration data, ensuring consistency and fault tolerance.
- kube-scheduler: responsible for scheduling containers to run on individual nodes based on resource requirements and other constraints.
- kube-controller-manager: manages controller processes that regulate the state of the cluster, such as node and replication controllers.
Node Components
- kubelet: an agent that runs on each node in the cluster and ensures that containers are running in a Pod.
- kube-proxy: maintains network rules on nodes, enabling communication between Pods and external traffic.
Add-ons
- DNS (kube-dns/coredns): provides DNS-based service discovery for services within the cluster.
- Dashboard: a web-based user interface for managing and monitoring the Kubernetes cluster.
- Ingress Controller: manages external access to services within the cluster, typically by exposing HTTP and HTTPS routes.
- Container Network Interface (CNI): defines how networking is established between Pods.
Pods
The smallest and simplest deployable object in the Kubernetes object model, representing one or more containers deployed together on a node.
Controllers
- Replication Controller/ReplicaSet: ensures that a specified number of replicas for a Pod are running at all times.
- Deployment: provides declarative updates to applications, allowing them to be scaled up or down and updated with ease.
- StatefulSet: manages the deployment and scaling of a set of Pods with unique, stable network identifiers.
Storage
Persistent Volumes (PV) and Persistent Volume Claims (PVC) provide a way for containers to access persistent storage.
These components work together to create a scalable and resilient container orchestration platform. Kubernetes allows users to deploy and manage containerized applications efficiently, abstracting away the underlying infrastructure complexities.