I’m one of the IBM Cloud App Service architects and have been involved in leading the team in the engineering and delivery of this tool for accelerating the development of cloud-native apps.
After giving an overview of app architecture and stating the game plan, I’ll take you through video demos of creating two microservices and an iOS mobile front-end.
Cloud-native use case: Building an order management app
Although this diagram seems complicated with its many different boxes, what I want to highlight is that a cloud-native architecture supports building tens of different microservices that can run in many different compute environments–from virtual machines, platform-as-a-service container runtimes, or serverless functions.
Typically, microservices in cloud-native apps are very loosely coupled, and they are associated with each other through the use of APIs (and REST calls) and messaging technologies. In this diagram, we have multiple frontend digital channels (mobile apps, Web apps, maybe a voice-controlled device), with each communicating to their edge-of-network through a backend-to-frontend pattern. This is a common approach to cloud-native apps that, for example, enables deploying a new version of a mobile app and the APIs that support it without necessarily iterating all other parts of the overall application backend.
The backend-to-frontend orchestrates API calls into the various microservices below it. And, again, typically, you’d have business-logic microservices and maybe foundational-persistence or integration microservices. And then right at the back end are core, high-value, cloud-native services like an integrating database in the form of cloud or object storage or an Elasticsearch engine for doing indexing or integrating with some of the value through a blockchain network or a Watson conversation.
I’m going to create the three highlighted microservices, wire them together, and get my mobile app to click all the way through to my backend microservices app. Let’s say we already have a products database, and we need to provide a products microservice that can integrate with that database. So first, I’ll use Spring Boot as the technology in Java to build that microservice, deploying it into a Kubernetes environment. And second, I’ll build the backend-to-frontend in Node and Express, connecting that Node/Express app to the Spring app. Third, I’ll expose that backend-to-frontend using API Connect to give us a robust, secure API that we can then provide through to the mobile app.