Structural Patterns

Structural patterns are focused on the composition of building blocks to create higher-level complex resources. In microservice architecture, applications are packaged and deployed as containers. This approach makes it easier to scale applications with less overhead and more isolation. However, this makes it difficult to schedule and run related containers side-by-side, or sequentially in a cluster with thousands of nodes. For instance, if you want to run your frontend and backend containers together in a cluster, you need to find a mechanism so that you can always schedule them to the same nodes. Likewise, if you need to fill in configuration file templates before starting your application, there is a need to ensure that configuration handler containers are running before the application is.

In Kubernetes, containers are the building blocks that are encapsulated in pods. As a container orchestrator, Kubernetes provides built-in functionalities for organizing containers within pods. In this section, the sidecar and initialization structural design patterns for Kubernetes will be explained.