Kubernetes Pods
A Pod is a Kubernetes abstraction that represents a group of one or more application containers (such as Docker or rkt), and some shared resources for those containers. Those resources include:
- Shared storage, as Volumes
- Networking, as a unique cluster IP address
- Information about how to run each container, such as the container image version or specific ports to use.
A Pod models an application-specific "logical host" and can contain different application containers which are relatively tightly coupled
Nodes
A Pod always runs on a Node. A Node is a worker machine in Kubernetes and may be either a virtual or a physical machine. A Node can have multiple pods, and the Kubernetes master automatically handles scheduling the pods across the Nodes in the cluster.
Every Kubernetes Node runs at least:
- Kubelet, a process responsible for communication between the Kubernetes Master and the Node; it manages the Pods and the containers running on a machine.
- A container runtime (like Docker, rkt) responsible for pulling the container image from a registry, unpacking the container, and running the application.
