Book Image

Feature Management with LaunchDarkly

By : Michael Gillett
Book Image

Feature Management with LaunchDarkly

By: Michael Gillett

Overview of this book

Over the past few years, DevOps has become the de facto approach for designing, building, and delivering software. Feature management is now extending the DevOps methodology to allow applications to change on demand and run experiments to validate the success of new features. If you want to make feature management happen, LaunchDarkly is the tool for you. This book explains how feature management is key to building modern software systems. Starting with the basics of LaunchDarkly and configuring simple feature flags to turn features on and off, you'll learn how simple functionality can be applied in more powerful ways with percentage-based rollouts, experimentation, and switches. You'll see how feature management can change the way teams work and how large projects, including migrations, are planned. Finally, you'll discover various uses of every part of the tool to gain mastery of LaunchDarkly. This includes tips and tricks for experimentation, identifying groups and segments of users, and investigating and debugging issues with specific users and feature flag evaluations. By the end of the book, you'll have gained a comprehensive understanding of LaunchDarkly, along with knowledge of the adoption of trunk-based development workflows and methods, multi-variant testing, and managing infrastructure changes and migrations.
Table of Contents (18 chapters)
1
Section 1: The Basics
5
Section 2:Getting the Most out of Feature Management
11
Section 3: Mastering LaunchDarkly

Learning new ways to test your infrastructure

Once feature flags have been implemented on the backend systems, in addition to the frontend applications, some new testing opportunities can make use of controlling what downstream systems are being requested. By this, I mean that a client application's use of LaunchDarkly can target a different endpoint or configuration so that a different backend service is called for testing. This is not the type of testing that will validate that components function as expected or that systems integrate well; instead, this testing relies on the fact that the production environment itself can be safely tested. In previous chapters, especially Chapter 5, Experimentation, the focus was on being able to evaluate the features of the production environment. With this approach to testing, it is also possible to assess the infrastructure itself.

When discussing performing migrations in the previous section, we explained that different endpoints could...