cmd/containerboot,cmd/k8s-operator: reload tailscaled config (#14342)

cmd/{k8s-operator,containerboot}: reload tailscaled configfile when its contents have changed

Instead of restarting the Kubernetes Operator proxies each time
tailscaled config has changed, this dynamically reloads the configfile
using the new reload endpoint.
Older annotation based mechanism will be supported till 1.84
to ensure that proxy versions prior to 1.80 keep working with
operator 1.80 and newer.

Updates tailscale/tailscale#13032
Updates tailscale/corp#24795

Signed-off-by: Irbe Krumina <irbe@tailscale.com>

cmd/k8s-operator/proxygroup_specs.go

@@ -21,7 +21,7 @@ import (
 
 // Returns the base StatefulSet definition for a ProxyGroup. A ProxyClass may be
 // applied over the top after.
-func pgStatefulSet(pg *tsapi.ProxyGroup, namespace, image, tsFirewallMode, cfgHash string) (*appsv1.StatefulSet, error) {
+func pgStatefulSet(pg *tsapi.ProxyGroup, namespace, image, tsFirewallMode string) (*appsv1.StatefulSet, error) {
 	ss := new(appsv1.StatefulSet)
 	if err := yaml.Unmarshal(proxyYaml, &ss); err != nil {
 		return nil, fmt.Errorf("failed to unmarshal proxy spec: %w", err)
@@ -53,9 +53,6 @@ func pgStatefulSet(pg *tsapi.ProxyGroup, namespace, image, tsFirewallMode, cfgHa
 		Namespace:                  namespace,
 		Labels:                     pgLabels(pg.Name, nil),
 		DeletionGracePeriodSeconds: ptr.To[int64](10),
-		Annotations: map[string]string{
-			podAnnotationLastSetConfigFileHash: cfgHash,
-		},
 	}
 	tmpl.Spec.ServiceAccountName = pg.Name
 	tmpl.Spec.InitContainers[0].Image = image