Webinar Series: Building Containerized Applications

Introduction

In the last tutorial, How to Install and Configure Docker, we explored one method for converting Docker containers into Docker images. Although the method we used worked, it is not always the optimal way of building images.

In many cases, you’ll want to bring existing code into container images, and you’ll want a repeatable, consistent mechanism for creating Docker images that are in sync with the latest version of your codebase.

A Dockerfile addresses these requirements by providing a declarative and consistent way of building Docker images.

Additionally, you’ll sometimes want to containerize entire applications which are composed of multiple, heterogeneous containers that are deployed and managed together.

Docker Compose, like a Dockerfile, takes a declarative approach to provide you with a method for defining an entire technology stack, including network and storage requirements. This not only makes it easier to build containerized applications, but it also makes it easier to manage and scale them.

In this tutorial, you will use a sample web application based on Node.js and MongoDB to build a Docker image from a Dockerfile, you will create a custom network that allows your Docker containers to communicate, and you will use Docker Compose to launch and scale a containerized application.