Kubernetes Pod and Container Concepts: Difference between revisions
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* [[Kubernetes_Concepts#Subjects|Kubernetes Concepts]] | * [[Kubernetes_Concepts#Subjects|Kubernetes Concepts]] | ||
=Overview= | =Overview= | ||
A [[#Pod|pod]] is the fundamental, atomic compute unit created and managed by Kubernetes. An application is deployed as one or more equivalent pods | A [[#Pod|pod]] is the fundamental, atomic compute unit created and managed by Kubernetes. An application is deployed as one or more equivalent pods. There are various strategies to partition applications to pods. A pod groups together one or more [[#Container|containers]]. There are several [[#Container_Types|types]] of containers: [[#Application_Container|application containers]], [[#Init_Container|init containers]] and [[#Ephemeral_Container|ephemeral containers]]. Pods are deployed on [[Kubernetes_Control_Plane_and_Data_Plane_Concepts#Worker_Node|worker nodes]]. A pod has a well-defined [[#Pod_Lifecycle|lifecycle]] with several [[#Pod_Phases|phases]], and the pod's containers can only be in one of a well-defined number of [[#Container_States|states]]. Kubernetes learns of what happens with a container by [[#Container_Probes|container probes]]. | ||
=Pod= | =Pod= | ||
Revision as of 18:30, 24 September 2021
External
- https://kubernetes.io/docs/concepts/workloads/pods/ (fully synced ✓)
Internal
Overview
A pod is the fundamental, atomic compute unit created and managed by Kubernetes. An application is deployed as one or more equivalent pods. There are various strategies to partition applications to pods. A pod groups together one or more containers. There are several types of containers: application containers, init containers and ephemeral containers. Pods are deployed on worker nodes. A pod has a well-defined lifecycle with several phases, and the pod's containers can only be in one of a well-defined number of states. Kubernetes learns of what happens with a container by container probes.
Pod
A pod is a group of one or more containers Kubernetes deploys and manages a compute unit, and the specification for how to run the containers. Kubernetes will not manage compute entities with smaller granularity, such as containers or processes.
The containers of a pod are atomically deployed and managed as a group. A useful mental model when thinking of a pod is that of a logical host, where all its containers share a context.
Pod Operation Atomicity
The containers in a pod share network resources and storage. From this perspective, a pod can be thought of as a logical host with all its processes (containers) sharing the network stack and the storage available to the host.
Pod Lifecycle
Pod Phases
Pods and Nodes
Pods and Containers
Container
TODO:
Container Types
Application Container
Init Container
Ephemeral Container
Container States
Container Probes
Summary of a relationship between container probe result and overall pod situation.