Summary

Configuration is one of the critical markers of code base health. In this chapter, you’ve learned how managing configuration can become a maintainability problem and a productivity bottleneck. You’ve learned about the built-in Rails mechanisms to provide configuration information. You’ve become familiar with the Twelve-Factor methodology and how it has made environment variables the most popular way for storing configuration.

You’ve learned about the problems related to the heavy usage of ENV in the code base. You’ve learned how to classify configuration parameters into different kinds (settings and secrets) and how it affects decisions about where to store them. You’ve learned how to separate application code and configuration sources the Rails way. You’ve also learned how introducing configuration objects helps to keep configuration under control and provides a better developer experience.

In the next chapter, we will...