cmd/k8s-operator,k8s-operator: allow the operator to deploy exit nodes via Connector custom resource (#10724)

cmd/k8s-operator/deploy/crds,k8s-operator/apis/v1alpha1: allow to define an exit node via Connector CR.

Make it possible to define an exit node to be deployed to a Kubernetes cluster
via Connector Custom resource.

Also changes to Connector API so that one Connector corresponds
to one Tailnet node that can be either a subnet router or an exit
node or both.

The Kubernetes operator parses Connector custom resource and,
if .spec.isExitNode is set, configures that Tailscale node deployed
for that connector as an exit node.

Signed-off-by: Irbe Krumina <irbe@tailscale.com>
Co-authored-by: Anton Tolchanov <anton@tailscale.com>

cmd/k8s-operator/deploy/examples/connector.yaml

@@ -0,0 +1,19 @@
+# Before applying ensure that the operator owns tag:prod.
+# https://tailscale.com/kb/1236/kubernetes-operator/#setting-up-the-kubernetes-operator.
+# To set up autoapproval set tag:prod as approver for 10.40.0.0/14 route and exit node.
+# Otherwise approve it manually in Machines panel once the
+# ts-prod Tailscale node has been created.
+# See https://tailscale.com/kb/1018/acls/#auto-approvers-for-routes-and-exit-nodes
+apiVersion: tailscale.com/v1alpha1
+kind: Connector
+metadata:
+  name: prod
+spec:
+  tags:
+  - "tag:prod"
+  hostname: ts-prod
+  subnetRouter:
+    advertiseRoutes:
+    - "10.40.0.0/14"
+    - "192.168.0.0/14"
+  exitNode: true

cmd/k8s-operator/deploy/examples/subnetrouter.yaml

@@ -1,17 +0,0 @@
-# Before applyong this ensure that the operator is owner of tag:subnet.
-# https://tailscale.com/kb/1236/kubernetes-operator/#setting-up-the-kubernetes-operator.
-# To set up autoapproval set tag:subnet as approver for 10.40.0.0/14 route
-# otherwise you will need to approve it manually in control panel once the
-# subnet router has been created.
-# https://tailscale.com/kb/1019/subnets/#advertise-subnet-routes
-apiVersion: tailscale.com/v1alpha1
-kind: Connector
-metadata:
-  name: exposepods
-spec:
-  subnetRouter:
-    routes:
-    - "10.40.0.0/14"
-    tags:
-    - "tag:subnet"
-    hostname: pods-subnetrouter