Kubernetes.md

Kubernetes

Terminolgy

Node

• A worker machine
• Runs node components
• Spezialization
  • Master
    • Runs master components

Workload

• Either a Pod or Controller

Pod

• Smallest deployable units of computing
• A Pod encapsulates
  • One or more application containers
  • Storage resources
  • A unique network IP
  • Options

Controller

• E.g. a ReplicaSet or Deployment

ReplicaSet

• Ensures that a specified number of Pod replicas are running at any one time

Deployment

• Defines a desired state of an application
• Provides declarative updates for Pods and ReplicaSets

Service

• An abstraction which defines a logical set of Pods and a policy by which to access them.
• Services types:
  • ClusterIP (default) exposes the service on an internal IP in the cluster
  • NodePort exposes the service using the container port
  • LoadBalancer creates an external load balancer service (if supported) and assigns a fixed, external IP to the service
  • ExternalName exposes the service using an arbitrary name

Resources:

• Using Source IP
• Connecting Applications with Services
• Labels and Selectors