Kubernetes Concepts: Difference between revisions
| Line 44: | Line 44: | ||
{{Internal|OpenShift Concepts#Service|OpenShift Service}} | {{Internal|OpenShift Concepts#Service|OpenShift Service}} | ||
Revision as of 21:55, 29 April 2017
External
Internal
Overview
Pod
One or more containers deployed together on one host, containing collocated applications that are relatively tightly coupled and run with a shared context. The containers in a pod share resources as IP addresses and volumes. The pod is the smallest unit that can be defined, deployed and managed. Kubernetes orchestrates pods.
Complex applications can be made of any pods.
Storage
Volume
etcd
A distributed key/value datastore for state within the environment.
Scheduler
The scheduler is a component that runs on master and determines the best fit for running pods across the environment. The scheduler also spreads pod replicas across nodes, for application HA.
Namespace
Service
A service represents a group of pods and provides the permanent IP and hostname for other applications to use. A service resource is an abstraction that defines a logical set of pods and a policy that is used to access the pods. The service layer is how applications communicate with one another.