The DevOps Handbook: How to Create World-Class Agility, Reliability, & Security in Technology Organizations

by Gene Kim

In this context, environment is defined as everything in the application stack except for the application, including the databases, operating systems, networking, virtualization, and all associated configurations. † Most developers want to test their code, and they have often gone to extreme lengths to obtain test environments to do so. Developers have been known to reuse old test environments from previous projects (often years old) or ask someone who has a reputation of being able to find one—they just won’t ask where it came from because, invariably, someone somewhere is now missing a server. ‡ Ideally, we should be finding errors before integration testing, when it is too late in the testing cycle to create fast feedback for developers. If we are unable to do so, we likely have an architectural issue that needs to be addressed. Designing our systems for testability, to include the ability to discover most defects using a nonintegrated virtual environment on a development workstation, is a key part of creating an architecture that supports fast flow and feedback.