Add support for private gateway (#154)

This change adds support for TCPRoutes when using a private gateway
class. This is similar to annotating services today. It also moves the
gateway classes to the Helm chart as it makes things a lot simpler for
the end user as they no longer have to define them.

Signed-off-by: Philip Laine <philip.laine@gmail.com>

examples/gateway-api/README.md

@@ -0,0 +1,46 @@
+# Gateway API
+
+This example walks you through how to setup a Netbird Gateway API and expose Nginx through the Netbird proxy service.
+
+Build image locally and load it into Kind.
+```shell
+make docker-build IMG=docker.io/netbirdio/kubernetes-operator:dev
+kind load docker-image docker.io/netbirdio/kubernetes-operator:dev
+```
+
+Install the Gateway API CRDs.
+
+```shell
+kubectl apply --server-side -f https://github.com/kubernetes-sigs/gateway-api/releases/download/v1.5.0/experimental-install.yaml
+```
+
+Create Netbird namespace and API key secret.
+
+```shell
+kubectl create namespace netbird
+kubectl -n netbird create secret generic netbird-mgmt-api-key --from-literal NB_API_KEY=${NETBIRD_API_KEY}
+```
+
+Install the Kubernetes Operator. Make sure to use the customized values to enable Gateway API support. This assumes you have already created a secret containing a Netbird API key.
+
+```shell
+helm upgrade --install --create-namespace -f ./examples/gateway-api/values.yaml -n netbird netbird-operator ./helm/kubernetes-operator
+```
+
+Create the gateway along with the routing peer. This will deploy Netbird clients that route traffic into the cluster.
+
+```shell
+kubectl apply -f ./examples/gateway-api/gateway.yaml
+```
+
+Deploy the test Nginx application along with a HTTPRoute. The HTTPRoute will expose the service through Netbirds public proxy.
+
+```shell
+kubectl apply -f ./examples/gateway-api/nginx.yaml
+```
+
+Expose the Kubernetes API server service as a network resource in Netbird.
+
+```shell
+kubectl apply -f ./examples/gateway-api/kubernetes.yaml
+```