Ingresses

Ingresses refer to entry points for external traffic entering a network, system, or application. In computing, the term often denotes mechanisms that manage how external clients reach internal services or resources. In traditional networks, an ingress point might be a gateway, firewall, or edge router that controls and monitors inbound connections.

In Kubernetes, an Ingress is a API object that defines rules for routing external HTTP or HTTPS traffic to services within a cluster. An Ingress relies on an Ingress Controller to implement these rules, typically by configuring a load balancer or reverse proxy. Ingress can provide host-based routing, path-based routing, and TLS termination, allowing multiple services to be exposed under a single external IP or hostname. It can simplify external access and enable features such as URL-based routing and centralized management of certificates.

Other contexts use the term ingresses to describe entry points into larger networks or systems. Ingress points are common targets for security controls, including authentication, rate limiting, and inspection. The concept is often contrasted with egress, which describes outbound traffic leaving a network or device. Cloud providers offer managed Ingress solutions that integrate with their load balancers and DNS, while on-premises deployments may combine Ingress Controllers with different proxy technologies. Limitations of Ingress include variability in feature support across controllers and potential complexity for advanced traffic policies; in such cases, service meshes or dedicated gateway solutions may be used.

See also: Ingress Controller, Egress, Load balancer, Kubernetes, Networking.