TCP routing
Experimental Channel
The TCPRoute
resource described below is currently only included in the
"Experimental" channel of Gateway API. For more information on release
channels, refer to our versioning guide.
Gateway API is designed to work with multiple protocols and TCPRoute is one such route which allows for managing TCP traffic.
In this example, we have one Gateway resource and two TCPRoute resources that distribute the traffic with the following rules:
- All TCP streams on port 8080 of the Gateway are forwarded to port 6000 of
my-foo-service
Kubernetes Service. - All TCP streams on port 8090 of the Gateway are forwarded to port 6000 of
my-bar-service
Kubernetes Service.
In this example two TCP
listeners will be applied to the Gateway
in order to route them to two separate backend TCPRoutes
, note that the
protocol
set for the listeners
on the Gateway
is TCP
:
apiVersion: gateway.networking.k8s.io/v1
kind: Gateway
metadata:
name: my-tcp-gateway
spec:
gatewayClassName: my-tcp-gateway-class
listeners:
- name: foo
protocol: TCP
port: 8080
allowedRoutes:
kinds:
- kind: TCPRoute
- name: bar
protocol: TCP
port: 8090
allowedRoutes:
kinds:
- kind: TCPRoute
---
apiVersion: gateway.networking.k8s.io/v1alpha2
kind: TCPRoute
metadata:
name: tcp-app-1
spec:
parentRefs:
- name: my-tcp-gateway
sectionName: foo
rules:
- backendRefs:
- name: my-foo-service
port: 6000
---
apiVersion: gateway.networking.k8s.io/v1alpha2
kind: TCPRoute
metadata:
name: tcp-app-2
spec:
parentRefs:
- name: my-tcp-gateway
sectionName: bar
rules:
- backendRefs:
- name: my-bar-service
port: 6000
In the above example we separate the traffic for the two separate backend TCP
Services by using the sectionName
field in the parentRefs
:
spec:
parentRefs:
- name: my-tcp-gateway
sectionName: foo
This corresponds directly with the name
in the listeners
in the Gateway
:
listeners:
- name: foo
protocol: TCP
port: 8080
- name: bar
protocol: TCP
port: 8090
In this way each TCPRoute
"attaches" itself to a different port on the
Gateway
so that the service my-foo-service
is taking traffic for port 8080
from outside the cluster and my-bar-service
takes the port 8090
traffic.
Note that you can achieve this same result by binding the Routes to the Gateway
listeners using the port
field in the parentRefs
:
spec:
parentRefs:
- name: my-tcp-gateway
port: 8080
Using the port
field instead of sectionName
for the attachment has the
downside of more tightly coupling the relationship between the Gateway and
its associated Routes. Refer to Attaching to Gateways for more
details.