Book Image

Docker on Windows

By : Elton Stoneman
Book Image

Docker on Windows

By: Elton Stoneman

Overview of this book

Docker is a platform for running server applications in lightweight units called containers. You can run Docker on Windows Server 2016 and Windows 10, and run your existing apps in containers to get significant improvements in efficiency, security, and portability. This book teaches you all you need to know about Docker on Windows, from 101 to deploying highly-available workloads in production. This book takes you on a Docker journey, starting with the key concepts and simple examples of how to run .NET Framework and .NET Core apps in Windows Docker containers. Then it moves on to more complex examples—using Docker to modernize the architecture and development of traditional ASP.NET and SQL Server apps. The examples show you how to break up monoliths into distributed apps and deploy them to a clustered environment in the cloud, using the exact same artifacts you use to run them locally. To help you move confidently to production, it then explains Docker security, and the management and support options. The book finishes with guidance on getting started with Docker in your own projects, together with some real-world case studies for Docker implementations, from small-scale on-premises apps to very large-scale apps running on Azure.
Table of Contents (20 chapters)
Title Page
Credits
About the Author
About the Reviewer
www.PacktPub.com
Customer Feedback
Preface
Index

Separating dependencies


In the last chapter, I dockerized the legacy NerdDinner app and got it running but without a database. The original application expected to use SQL Server LocalDB on the same host where the app is running. LocalDB is an MSI-based installation, and I can add it to the Docker image, just by downloading the MSI and installing it with RUN commands in the Dockerfile. But this means that when I start a container from the image, it has two functions hosting a web application and running a database.

Note

Having two functions in one container is not a good idea; what would happen if you wanted to upgrade your website without changing the database? Or, what if you needed to do some maintenance on the database, which didn't impact the website? What if you need to scale out the website? By coupling the two functions together, you've added a deployment risk, test effort, and administration complexity and reduced your operational flexibility.

Instead, I'm going to package the database...