Book Image

Learn Docker - Fundamentals of Docker 19.x - Second Edition

By : Dr. Gabriel N. Schenker
Book Image

Learn Docker - Fundamentals of Docker 19.x - Second Edition

By: Dr. Gabriel N. Schenker

Overview of this book

Containers enable you to package an application with all the components it needs, such as libraries and other dependencies, and ship it as one package. Docker containers have revolutionized the software supply chain in both small and large enterprises. Starting with an introduction to Docker fundamentals and setting up an environment to work with it, you’ll delve into concepts such as Docker containers, Docker images, and Docker Compose. As you progress, the book will help you explore deployment, orchestration, networking, and security. Finally, you’ll get to grips with Docker functionalities on public clouds such as Amazon Web Services (AWS), Azure, and Google Cloud Platform (GCP), and learn about Docker Enterprise Edition features. Additionally, you’ll also discover the benefits of increased security with the use of containers. By the end of this Docker book, you’ll be able to build, ship, and run a containerized, highly distributed application on Docker Swarm or Kubernetes, running on-premises or in the cloud.
Table of Contents (25 chapters)
1
Section 1: Motivation and Getting Started
4
Section 2: Containerization, from Beginner to Black Belt
11
Section 3: Orchestration Fundamentals and Docker Swarm
18
Section 4: Docker, Kubernetes, and the Cloud

Chapter 3

Here are some sample answers to the questions presented in this chapter:

  1. The possible states of a Docker container are as follows:
    • created: A container that has been created but not started
    • restarting: A container that is in the process of being restarted
    • running: A currently running container
    • paused: A container whose processes have been paused
    • exited: A container that ran and completed
    • dead: A container that the Docker engine tried and failed to stop
  2. We can use docker container ls (or the old, shorter version, docker ps) to list all containers that are currently running on our Docker host. Note that this will NOT list the stopped containers, for which you need the extra parameter--all (or -a).
  3. To list all IDs of containers, running or stopped, we can use docker container ls -a -q, where -q stands for output ID only.
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