fix: re-implement status update flags (#1514)

This patch re-implements the --status-update flag for KIC 2.0
but also deprecates the --update-status-on-shutdown flag as the
behavior of tearing down on cleanup is somewhat in conflict with
the idempontent and eventually consistent design of KIC 2.0.

CHANGELOG.md

@@ -47,6 +47,10 @@
 - The historical `--stderrthreshold` flag is now deprecated: it no longer has
   any effect when used and will be removed in a later release.
   [#1297](https://github.com/Kong/kubernetes-ingress-controller/issues/1297)
+- The `--update-status-on-shutdown` flag which supplements the `--update-status`
+  flag has been deprecated and will no longer have any effect, it will be removed
+  in a later release.
+  [#1304](https://github.com/Kong/kubernetes-ingress-controller/issues/1304)
 
 ## [2.0.0-alpha.2] - 2021/07/07
 

railgun/manager/run.go

@@ -173,7 +173,12 @@ func Run(ctx context.Context, c *config.Config) error {
 		return err
 	}
 
-	go ctrlutils.PullConfigUpdate(ctx, kongConfig, logger, kubeconfig, c.PublishService, c.PublishStatusAddress)
+	if c.UpdateStatus {
+		setupLog.Info("status updates enabled, status update routine is being started in the background.")
+		go ctrlutils.PullConfigUpdate(ctx, kongConfig, logger, kubeconfig, c.PublishService, c.PublishStatusAddress)
+	} else {
+		setupLog.Info("WARNING: status updates were disabled, resources like Ingress objects will not receive updates to their statuses.")
+	}
 
 	alwaysEnabled := util.EnablementStatusEnabled
 	controllers := []ControllerDef{

railgun/pkg/config/config.go

@@ -60,6 +60,7 @@ type Config struct {
 	// Ingress status
 	PublishService       string
 	PublishStatusAddress []string
+	UpdateStatus         bool
 
 	// Kubernetes API toggling
 	IngressExtV1beta1Enabled util.EnablementStatus
@@ -150,6 +151,8 @@ func (c *Config) FlagSet() *pflag.FlagSet {
 	flagSet.StringSliceVar(&c.PublishStatusAddress, "publish-status-address", []string{}, `User-provided addresses in
 			comma-separated string format, for use in lieu of "publish-service" when that Service lacks useful address
 			information (for example, in bare-metal environments).`)
+	flagSet.BoolVar(&c.UpdateStatus, "update-status", true,
+		`Indicates if the ingress controller should update the status of resources (e.g. IP/Hostname for v1.Ingress, e.t.c.)`)
 
 	// Kubernetes API toggling
 	flagSet.enablementStatusVar(&c.IngressNetV1Enabled, "controller-ingress-networkingv1", util.EnablementStatusEnabled, "Enable or disable the Ingress controller (using API version networking.k8s.io/v1)."+onOffUsage)
@@ -189,6 +192,7 @@ func (c *Config) FlagSet() *pflag.FlagSet {
 			proxy.DefaultSyncSeconds,
 		))
 	flagSet.Int("stderrthreshold", 0, "DEPRECATED: has no effect and will be removed in future releases (see github issue #1297)")
+	flagSet.Bool("update-status-on-shutdown", false, `DEPRECATED: no longer has any effect and will be removed in a later release (see github issue #1304)`)
 
 	return &flagSet.FlagSet
 }