Istio Explained

Chapter 3. Adding Services to the Mesh

The objective of this chapter is to show you how to incrementally add services to the mesh where the services are part of a brownfield application. As part of adding services to the mesh, the mesh is actually integrated as part of the services themselves to make the mesh mostly transparent to the service implementation. A brownfield application is one that already exists versus creating a greenfield application, which is new and designed specifically for the environment it will run in. With a greenfield application, new code is developed allowing platform features to be added into the code. With a brownfield application, the code already exists and, in an ideal case, you don’t want to modify the code when moving into a new environment such as cloud. This chapter introduces you to the brownfield guiding application that will be used to demonstrate how the services of the application can be defined and introduced into the control of an Istio service mesh.

Introducing the Guiding Application

We have selected the IBM Stock Trader application as the guiding application for your cloud native journey experience because it is readily available and is representative of a simple brownfield application that would be taken to the cloud. The Stock Trader application works well for illustrative purposes because it has multiple interacting services as well as a persistent service; this will be important as we take you through the features of Istio.

The ...