Introduction

As with many of the topics covered in this book, security in a microservice architecture is about trade-offs. In a microservice architecture, individual code bases have limited responsibilities. If an attacker is able to compromise a single running service, they will only be able to perform actions that are governed by that particular microservice. The distributed nature of a microservice architecture, however, means that there are more targets for an attacker to potentially exploit in services running in separate clusters. The network traffic between those clusters, including traffic between edge services and internal services, presents many opportunities for an attacker to discover vulnerabilities.

Because of the distributed nature of microservice architectures, network topology must be considered when configuring how services are able to communicate with one another. This concern exists in monolithic code bases as well, where a running instance of a single code base needs...