Introduction to Docker Workshop: Containers and Images

--- title: Overview of the Docker workshop linkTitle: Docker workshop keywords: docker basics, how to start a docker container, container settings, setup docker, how to setup docker, setting up docker, docker container guide, how to get started with docker description: Get started with the Docker basics in this workshop, You'll learn about containers, images, and how to containerize your first application. aliases: - /guides/get-started/ - /get-started/hands-on-overview/ - /guides/workshop/ --- This 45-minute workshop contains step-by-step instructions on how to get started with Docker. This workshop shows you how to: - Build and run an image as a container. - Share images using Docker Hub. - Deploy Docker applications using multiple containers with a database. - Run applications using Docker Compose. > [!NOTE] > > For a quick introduction to Docker and the benefits of containerizing your > applications, see [Getting started](/get-started/introduction/_index.md). ## What is a container? A container is a sandboxed process running on a host machine that is isolated from all other processes running on that host machine. That isolation leverages [kernel namespaces and cgroups](https://medium.com/@saschagrunert/demystifying-containers-part-i-kernel-space-2c53d6979504), features that have been in Linux for a long time. Docker makes these capabilities approachable and easy to use. To summarize, a container: - Is a runnable instance of an image. You can create, start, stop, move, or delete a container using the Docker API or CLI. - Can be run on local machines, virtual machines, or deployed to the cloud. - Is portable (and can be run on any OS). - Is isolated from other containers and runs its own software, binaries, configurations, etc. If you're familiar with `chroot`, then think of a container as an extended version of `chroot`. The filesystem comes from the image. However, a container adds additional isolation not available when using chroot. ## What is an image? A running container uses an isolated filesystem. This isolated filesystem is provided by an image, and the image must contain everything needed to run an application - all dependencies, configurations, scripts, binaries, etc. The image also contains other configurations for the container, such as environment variables, a default command to run, and other metadata. ## Next steps In this section, you learned about containers and images. Next, you'll containerize a simple application and get hands-on with the concepts. {{< button text="Containerize an application" url="02_our_app.md" >}}

This document introduces a 45-minute Docker workshop that covers building and running container images, sharing images with Docker Hub, deploying multi-container applications with databases, and using Docker Compose. It defines containers as sandboxed, isolated processes running on a host machine and explains that containers are runnable instances of images. The document also defines images as isolated filesystems containing everything needed to run an application.