The ALB Ingress controller watches for Ingress resource changes in your Serverless Kubernetes (ASK) cluster and automatically provisions Application Load Balancer (ALB) instances, listeners, and routing rules to expose your Services to external traffic.
Key terms
| Term | Description |
|---|---|
| Ingress | A Kubernetes resource object that defines rules for routing external HTTP and HTTPS traffic to Services inside a cluster. |
| Service | A Kubernetes abstraction that provides a stable network identity for a group of replicated pods. |
| ALB Ingress controller | A controller that translates Ingress resources into ALB configuration — creating instances, listeners, and routing rules automatically. |
| AlbConfig | A custom resource definition (CRD) used by the ALB Ingress controller to configure an ALB instance and its listeners. Each AlbConfig object corresponds to one ALB instance. |
How the ALB Ingress controller works
When you create or update an Ingress resource, the ALB Ingress controller detects the change through the Kubernetes API server and performs the following operations in sequence:
Creates an ALB instance.
Configures listeners on the instance.
Creates Ingress rules.
Configures backend server groups.
The three core resources interact as follows:
Service — Defines the stable network endpoint that Ingresses route traffic to. A Service abstracts an application running across a group of replicated pods.
Ingress — Contains reverse proxy rules that determine how HTTP and HTTPS requests are routed to Services, matching on request host names and URL paths.
AlbConfig — Represents and configures the underlying ALB instance. The ALB Ingress controller generates an AlbConfig object for each managed ALB instance.
Key capabilities
The ALB Ingress controller supports:
| Capability | Description |
|---|---|
| Complex routing | Route traffic by host name and URL path. |
| Automatic certificate discovery | Retrieve and apply TLS certificates for HTTPS listeners automatically. |
| Multiple protocols | HTTP, HTTPS, and QUIC. |
| NGINX Ingress compatibility | Compatible with existing NGINX Ingress configurations. |
| Layer 7 elasticity | Handle high-volume traffic with ALB's built-in scaling and load balancing. |
Usage notes
ALB instances that serve Ingresses are fully managed by the ALB Ingress controller. Do not modify these ALB instances directly in the ALB console. Manual changes may conflict with controller-managed state and cause service interruptions.
For ALB quota information, see Functions and features.