12 Using Ingress to Route Traffic to Services
This chapter covers
- Creating Ingress objects
- Deploying and understanding Ingress controllers
- Securing ingresses with TLS
- Adding additional configuration to an Ingress
- Using IngressClasses when multiple controllers are installed
- Using Ingresses with non-service backends
In the previous chapter, you learned how to use the Service object to expose a group of pods at a stable IP address. If you use the LoadBalancer service type, the service is made available to clients outside the cluster through a load balancer. This approach is fine if you only need to expose a single service externally, but it becomes problematic with large numbers of services, since each service needs its own public IP address.
Fortunately, by exposing these services through an Ingress object instead, you only need a single IP address. Additionally, the Ingress provides other features such as HTTP authentication, cookie-based session affinity, URL rewriting, and others that Service objects can’t.
NOTE
You’ll find the code files for this chapter at https://github.com/luksa/kubernetes-in-action-2nd-edition/tree/master/Chapter12.
12.1 Introducing Ingresses
Before I explain what an Ingress is in the context of Kubernetes, it may help readers for whom English isn’t their first language to define what the term ingress means.
Definition
Ingress (noun)—The act of going in or entering; the right to enter; a means or place of entering; entryway.