What Is a Gateway in Microservices?

In a microservices architecture, a gateway is a service that acts as an entry point for all external client requests. The gateway is responsible for routing requests to the appropriate microservices and managing the communication between clients and microservices.

The gateway provides a single point of entry to the system, which simplifies the management of security, traffic, and other cross-cutting concerns. It can also help to decouple the microservices from the external world, allowing them to focus on their specific responsibilities.

In Kubernetes, there are a number of options for providing a gateway for external requests to backend services.

Full-featured Kubernetes Gateway

Implementations of the new Kubernetes Gateway API such as Envoy Gateway offer full-featured application gateway functionality for traffic ingress to Kubernetes clusters.

Advanced Kubernetes Gateway with Istio

Istio offers an advanced Gateway resource that enables incoming traffic into the Istio service mesh from outside the cluster. It is essentially a load balancer that manages external traffic and routes it to the appropriate service within the mesh.

The Istio Gateway is responsible for routing traffic to the appropriate destination based on various criteria, such as the incoming request’s URL or headers. It can be configured to use one or more virtual services, which define how traffic should be routed to specific destinations within the service mesh. This allows for fine-grained control over traffic routing and load balancing.

Enterprise solutions like Tetrate Service Bridge offer a global application connectivity and security platform for an entire fleet of applications across clusters, clouds, and on-premises.