When the Microservices approach became popular a few years ago, many companies rushed to build their own microservices or to convert their legacy applications into microservices. Over the years, companies have implemented an abundance of microservices, mostly with Spring Boot. Each of them manage their own configurations across deployment environments like Dev, Test, and Prod.
Due to the nature of a complex business process, there are many common configurations (e.g. databases, queues, email servers, and FTP servers, etc.) used in the distributed services. This can result in services having redundant and confusing configs on a distributed system. It can become challenging to update the configs for too many services on a distributed system across multiple environments.
Thankfully, Spring Cloud Config provides the implementation to successfully resolve these issues. It provides server-side and client-side support for externalized configuration in a distributed system. With the Config Server, you have a central place to manage external properties for applications across all environments. The concepts on both client and server map identically to the Spring Environment and PropertySource abstractions, so they fit very well with Spring applications.
In this post, I’ll demonstrate Config Server and Client with example code. I’ll show you how to use Git or a local repository as a central place to store all the config files. The diagram below illustrates how the distributed client services (e.g. Investment Position/Price/Reporting Data service) fetch their configuration from the Config Server, which in turn retrieves them from one central place.