Book Image

Learn Docker - Fundamentals of Docker 18.x

By : Dr. Gabriel N. Schenker
Book Image

Learn Docker - Fundamentals of Docker 18.x

By: Dr. Gabriel N. Schenker

Overview of this book

Docker containers have revolutionized the software supply chain in small and big enterprises. Never before has a new technology so rapidly penetrated the top 500 enterprises worldwide. Companies that embrace containers and containerize their traditional mission-critical applications have reported savings of at least 50% in total maintenance cost and a reduction of 90% (or more) of the time required to deploy new versions of those applications. Furthermore they are benefitting from increased security just by using containers as opposed to running applications outside containers. This book starts from scratch, introducing you to Docker fundamentals and setting up an environment to work with it. Then we delve into concepts such as Docker containers, Docker images, Docker Compose, and so on. We will also cover the concepts of deployment, orchestration, networking, and security. Furthermore, we explain Docker functionalities on public clouds such as AWS. By the end of this book, you will have hands-on experience working with Docker containers and orchestrators such as SwarmKit and Kubernetes.
Table of Contents (21 chapters)
Title Page
Packt Upsell
Contributors
Preface
Index

Comparing SwarmKit with Kubernetes


Now that we have learned a lot of details about the most important resources in Kubernetes, it is helpful to compare the two orchestrators, SwarmKit and Kubernetes, by matching the important resources. Here is the table:

SwarmKit

Kubernetes

Description

Swarm

Cluster

Set of servers/nodes managed by the respective orchestrator.

Node

Cluster member

Single host (physical or virtual) which is a member of the swarm/cluster.

Manager node

Master

Node managing the swarm/cluster. This is the control plane.

Worker node

Node

Member of the swarm/cluster running application workload.

Container

Container**

Instance of a container image running on a node. In a Kubernetes cluster, we cannot run a container.

Task

Pod

Instance of a service (swarm) or ReplicaSet (Kubernetes) running on a node. A task manages a single container while a Pod contains one to many containers that are all sharing the same network namespace.

Service

ReplicaSet

Defines and reconciles the desired state of an application service...