第12章クラウドネイティブアプリケーション開発

OpenShift is Red Hat’s cloud application platform. It includes several containerization software products, including the OpenShift Container Platform that runs on the Red Hat Linux operating system and Kubernetes. OpenShift is a Platform as a Service (PaaS) that includes the Kubernetes platform, Docker container images, as well as features that are exclusive to the OpenShift platform. Such features include CI/CD pipeline definitions, container automation tools, Kubernetes command-line interface, and security features. OpenShift provides a robust, multilanguage development environment, plus all the necessary software components to support applications. OpenShift is open-source and free-to-download application that enables developers to quickly deploy web, mobile, and IoT applications.

VMWare’s cloud application software Tanzu, formerly known as Cloud Foundry, is a modular, application platform that provides a rich set of developer tools and a pre-paved path to production to build and deploy applications quickly and securely on any compliant public cloud or on-premises Kubernetes cluster. Tanzu provides a supply chain of operational and security outcomes for the development environment via configurations that are designed with operational and security principles so that applications can be pushed into production quickly, run, and scaled safely and securely. Such principles include running code through a testing environment and ensuring the code runs properly, applying security scanning so that the application that goes into production is audited and compliant with security policies, and deploying the application to production environments that may include several cluster environments that can run and scale in production.

Node is an open-source, cross-platform, server-side JavaScript runtime environment that can be used to develop server-side tools and applications in JavaScript. Some examples of real-time applications include chats, news feeds, and other microservices. For example, Node can be used to create virtual servers and define the routes that connect microservices to external APIs such as operating system APIs, including HTTP and file system libraries, compared to browser-specific JavaScript APIs.

This Cloud Native Trail Map (https://openstax.org/r/76clnativemap) illustrates the use of various open-source tools to develop cloud-native applications.

Cloud-native applications have seen increased use in recent years and are predicted to be the future of software development. The Cloud Native Computing Foundation¹¹ estimated there were at least 6.8 million cloud-native developers in 2021 compared to 6.5 million in 2020. They also estimated there were 5.6 million developers using Kubernetes in 2021, up 67% from a year ago.¹²

11 https://www.cncf.io/ 12 https://www.cncf.io/blog/2021/12/20/new-slashdata-report-5-6-million-developers-use-kubernetes-an-increase-of-67-over-one-year/

• reducing IT overhead and management costs by providing a streamlined software delivery process and on-demand consumption of resources

• reducing time to market and reducing the risk of deployments by enabling developers to rapidly build, test, and deploy new and updated services

• ability to react faster in the market due to constant availability of resources

• reduction in complexity

• less coupling between the services in an application

Nevertheless, migrating to the cloud to improve operational efficiencies has a range of challenges. We also pointed out earlier some of the challenges faced in microservices architectures. Some of the challenges that were learned earlier include to use microservices requires changing the allocation of responsibility between components, and determining the components’ service boundaries could be difficult, debugging, logging, and monitoring microservices also become challenging, to name a few.

There are myriads of web apps that people use every day that are based on microservices. For example, weather apps typically leverage web services that invoke microservices. More complex applications include e-commerce websites, as illustrated earlier. Can you provide additional illustrative scenarios that demonstrate how the use of microservices help people in everyday life? Your scenarios should not be limited to describing how microservices are used, but rather should describe situations where these architectures are applied in real-life contexts.