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Exposing TCP and UDP services

Ingress does not support TCP or UDP services. For this reason this Ingress controller uses the flags --tcp-services-configmap and --udp-services-configmap to point to an existing config map where the key is the external port to use and the value indicates the service to expose using the format: <namespace/service name>:<service port>:[PROXY]:[PROXY]

It is also possible to use a number or the name of the port. The two last fields are optional. Adding PROXY in either or both of the two last fields we can use Proxy Protocol decoding (listen) and/or encoding (proxy_pass) in a TCP service (https://www.nginx.com/resources/admin-guide/proxy-protocol/).

The next example shows how to expose the service example-go running in the namespace default in the port 8080 using the port 9000

apiVersion: v1
kind: ConfigMap
metadata:
  name: tcp-configmap-example
data:
  9000: "default/example-go:8080"

Since 1.9.13 NGINX provides UDP Load Balancing. The next example shows how to expose the service kube-dns running in the namespace kube-system in the port 53 using the port 53

apiVersion: v1
kind: ConfigMap
metadata:
  name: udp-configmap-example
data:
  53: "kube-system/kube-dns:53"