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

by Gene Kim

To achieve this, we must create automated build and test processes that run in dedicated environments. This is critical for the following reasons: Our build and test process can run all the time, independent of the work habits of individual engineers. A segregated build and test process ensures that we understand all the dependencies required to build, package, run, and test our code (i.e., removing the “it worked on the developer’s laptop, but it broke in production” problem). We can package our application to enable the repeatable installation of code and configurations into an environment (e.g., on Linux RPM, yum, npm; on Windows, OneGet; alternatively framework-specific packaging systems can be used, such as EAR and WAR files for Java, gems for Ruby, etc.). Instead of putting our code in packages, we may choose to package our applications into deployable containers (e.g., Docker, Rkt, LXD, AMIs). Environments can be made more production-like in a way that is consistent and repeatable (e.g., compilers are removed from the environment, debugging flags are turned off, etc.).