Book Image

The Software Developer's Guide to Linux

By : David Cohen, Christian Sturm
5 (2)
Book Image

The Software Developer's Guide to Linux

5 (2)
By: David Cohen, Christian Sturm

Overview of this book

Developers are always looking to raise their game to the next level, yet most are completely lost when it comes to the Linux command line. This book is the bridge that will take you to the next level in your software development career. Most of the skills in the book can be immediately put to work to make you a more efficient developer. It’s written specifically for software engineers, not Linux system administrators, so each chapter will equip you with just enough theory to understand what you’re doing before diving into practical commands that you can use in your day-to-day work as a software developer. As you work through the book, you’ll quickly absorb the basics of how Linux works while you get comfortable moving around the command line. Once you’ve got the core skills, you’ll see how to apply them in different contexts that you’ll come across as a software developer: building and working with Docker images, automating boring build tasks with shell scripts, and troubleshooting issues in production environments. By the end of the book, you’ll be able to use Linux and the command line comfortably and apply your newfound skills in your day-to-day work to save time, troubleshoot issues, and be the command-line wizard that your team turns to.
Table of Contents (20 chapters)
18
Other Books You May Enjoy
19
Index

Configuration in Docker

Much of the software that software developers create now runs in containers, as opposed to traditional, full operating system environments. This dramatically simplifies how software expects to be configured.

In a container environment – whether it’s Docker or another container runtime – you’re dealing with a dramatically smaller environment. There are very few installed programs and utilities, a dramatically stripped-down init in place of systemd, and a much smaller filesystem that doesn’t have many of the directories we’ve mentioned here.

The principle of the configuration hierarchy still holds, though. Most containerized applications expect to get their configuration either as

  • environment variables, passed in by the container scheduler or the operator launching it,
  • a config file somewhere on the container filesystem, often dynamically created by the container scheduler just before the container is started, or
  • command...