Kubernetes Terminology
Kubernetes uses a range of terminology that we refer to in this guide. We
define these common terms for your reference:
- Pod
- When using the Kubernetes container orchestration engine, a pod is the
smallest deployable unit that can be created and managed. A pod is a
co-located group of application containers that run with a shared context.
When using Magnum, pods are created and managed within clusters. Refer to the
pods section in the Kubernetes
User Guide for more information.
- Replication controller
- A replication controller is used to ensure that at any given time a certain
number of replicas of a pod are running. Pods are automatically created and
deleted by the replication controller as necessary based on a template to
ensure that the defined number of replicas exist. Refer to the replication
controller section in
the Kubernetes User Guide for more information.
- Service
- A service is an additional layer of abstraction provided by the Kubernetes
container orchestration engine which defines a logical set of pods and a
policy for accessing them. This is useful because pods are created and
deleted by a replication controller, for example, other pods needing to
discover them can do so via the service abstraction. Refer to the
services section in the
Kubernetes User Guide for more information.