Question

Besides those 3, what other ingress controllers are there?

Answer 1

From:  https://kubernetes.io/docs/concepts/services-networking/ingress-controllers/

a. HA Proxy

b. Istio Ingress

c. Traefik kubernetes Ingress Provider

d. Skipper

e. Voyager

f. Tyk Operator

g. Gloo (open source)

h. AKS Application Gateway Ingress Controller (Azure)

i. Ambassador (envoy-based)

j. Enroute (another envoy-based Ingress Controlle