Proxy UDP traffic by port
Create a UDPRoute
or UDPIngress
resource, which will then be converted in to a Kong Gateway Service and Route.
Prerequisites
Kong Konnect
If you don’t have a Konnect account, you can get started quickly with our onboarding wizard.
- The following Konnect items are required to complete this tutorial:
- Personal access token (PAT): Create a new personal access token by opening the Konnect PAT page and selecting Generate Token.
-
Set the personal access token as an environment variable:
export KONNECT_TOKEN='YOUR KONNECT TOKEN'
Enable the Gateway API
-
Install the experimental Gateway API CRDs before installing Kong Ingress Controller:
kubectl apply -f https://github.com/kubernetes-sigs/gateway-api/releases/download/v1.3.0/experimental-install.yaml
-
Create a
Gateway
andGatewayClass
instance to use.
echo "
apiVersion: v1
kind: Namespace
metadata:
name: kong
---
apiVersion: gateway.networking.k8s.io/v1
kind: GatewayClass
metadata:
name: kong
annotations:
konghq.com/gatewayclass-unmanaged: 'true'
spec:
controllerName: konghq.com/kic-gateway-controller
---
apiVersion: gateway.networking.k8s.io/v1
kind: Gateway
metadata:
name: kong
spec:
gatewayClassName: kong
listeners:
- name: proxy
port: 80
protocol: HTTP
allowedRoutes:
namespaces:
from: All
" | kubectl apply -n kong -f -
Create a KIC Control Plane
Use the Konnect API to create a new CLUSTER_TYPE_K8S_INGRESS_CONTROLLER
Control Plane:
CONTROL_PLANE_DETAILS=$(curl -X POST "https://us.api.konghq.com/v2/control-planes" \
-H "Authorization: Bearer $KONNECT_TOKEN" \
--json '{
"name": "My KIC CP",
"cluster_type": "CLUSTER_TYPE_K8S_INGRESS_CONTROLLER"
}')
We’ll need the id
and telemetry_endpoint
for the values.yaml
file later. Save them as environment variables:
CONTROL_PLANE_ID=$(echo $CONTROL_PLANE_DETAILS | jq -r .id)
CONTROL_PLANE_TELEMETRY=$(echo $CONTROL_PLANE_DETAILS | jq -r '.config.telemetry_endpoint | sub("https://";"")')
Create mTLS certificates
Kong Ingress Controller talks to Konnect over a connected secured with TLS certificates.
Generate a new certificate using openssl
:
openssl req -new -x509 -nodes -newkey rsa:2048 -subj "/CN=kongdp/C=US" -keyout ./tls.key -out ./tls.crt
The certificate needs to be a single line string to send it to the Konnect API with curl. Use awk
to format the certificate:
export CERT=$(awk 'NF {sub(/\r/, ""); printf "%s\\n",$0;}' tls.crt);
Next, upload the certificate to Konnect:
curl -X POST "https://us.api.konghq.com/v2/control-planes/$CONTROL_PLANE_ID/dp-client-certificates" \
-H "Authorization: Bearer $KONNECT_TOKEN" \
--json '{
"cert": "'$CERT'"
}'
Finally, store the certificate in a Kubernetes secret so that Kong Ingress Controller can read it:
kubectl create namespace kong -o yaml --dry-run=client | kubectl apply -f -
kubectl create secret tls konnect-client-tls -n kong --cert=./tls.crt --key=./tls.key
Kong Ingress Controller running
-
Add the Kong Helm charts:
helm repo add kong https://charts.konghq.com helm repo update
-
Install Kong Ingress Controller using Helm:
helm install kong kong/ingress -n kong --create-namespace --set controller.ingressController.env.feature_gates="GatewayAlpha=true"
-
Set
$PROXY_IP
as an environment variable for future commands:export PROXY_IP=$(kubectl get svc --namespace kong kong-gateway-proxy -o jsonpath='{range .status.loadBalancer.ingress[0]}{@.ip}{@.hostname}{end}') echo $PROXY_IP
Required Kubernetes resources
This how-to requires some Kubernetes services to be available in your cluster. These services will be used by the resources created in this how-to.
kubectl apply -f https://developer.konghq.com/manifests/kic/udp-service.yaml -n kong
Add UDP listens
Kong Gateway doesn’t include any UDP listen configuration by default. To expose UDP listens, update the Deployment’s environment variables and port configuration.
-
Set the
KONG_STREAM_LISTEN
environment variable and expose port9999
in the Deployment:kubectl patch deploy -n kong kong-gateway --patch '{ "spec": { "template": { "spec": { "containers": [ { "name": "proxy", "env": [ { "name": "KONG_STREAM_LISTEN", "value": "0.0.0.0:9999 udp" } ], "ports": [ { "containerPort": 9999, "name": "stream9999", "protocol": "UDP" } ] } ] } } } }'
-
Update the proxy Service to indicate the new ports:
kubectl patch service -n kong kong-gateway-proxy --patch '{ "spec": { "ports": [ { "name": "stream9999", "port": 9999, "protocol": "UDP", "targetPort": 9999 } ] } }'
Route UDP traffic
To expose the service to the outside world, create a UDPRoute resource for Gateway APIs or a UDPIngress resource for Ingress.
This configuration routes traffic to UDP port 9999
on the
Kong Gateway proxy to port 9999
on the TFTP test server.
Validate your configuration
Send a TFTP request through the proxy:
curl -s tftp://$PROXY_IP:9999/hello
The results should look like this:
Hostname: tftp-5849bfd46f-nqk9x
Request Information:
client_address=10.244.0.1
client_port=39364
real path=/hello
request_scheme=tftp
Cleanup
Delete created Kubernetes resources
kubectl delete -n kong -f https://developer.konghq.com/manifests/kic/udp-service.yaml
Uninstall KIC from your cluster
helm uninstall kong -n kong