Kubernetes Patterns

Chapter 16. Adapter

The Adapter pattern takes a heterogeneous containerized system and makes it conform to a consistent, unified interface with a standardized and normalized format that can be consumed by the outside world. The Adapter pattern inherits all its characteristics from the Sidecar, but has the single purpose of providing adapted access to the application.

Problem

Containers allow us to package and run applications written in different libraries and languages in a unified way. Today, it is common to see multiple teams using different technologies and creating distributed systems composed of heterogeneous components. This heterogeneity can cause difficulties when all components have to be treated in a unified way by other systems. The Adapter pattern offers a solution by hiding the complexity of a system and providing unified access to it.

Solution

The best way to illustrate this pattern is through an example. A major prerequisite for successfully running and supporting distributed systems is providing detailed monitoring and alerting. Moreover, if we have a distributed system composed of multiple services we want to monitor, we may use an external monitoring tool to poll metrics from every service and record them.

However, services written in different languages may not have the same capabilities and may not expose metrics in the same format expected by the monitoring tool. This diversity creates a challenge for monitoring such a heterogeneous application from a ...