Running multiple services locally

With microservice architecture playing such a significant role in building App Engine applications, it's important to be able to perform integration tests between services. There are a number of ways to do this in general, but the App Engine development server provides a convenient method by supporting multiple running services.

To run multiple services simultaneously in the App Engine development server, simply specify each service's configuration file when calling dev_appserver.py. To run our default service and our new colors service together, run the following command from the chapter_04 directory:

dev_appserver.py example_01/app.yaml example_02/app.yaml

When running multiple services, the App Engine development server will run each specified service on incrementing ports, starting with port 8080. Simulated service integrations such as Memcache and Datastore will be shared across services, as they are in App Engine.

All running services can be managed from within the development server admin console, shown as follows: