Addition of configurable preStop sleep with env variable PRE_STOP_SLEEP_SECONDS

Author: sjanel

README.md

@@ -177,12 +177,13 @@ spec:
   ...
 ```
 
-| Variable name                  | Default                           | Description                                             |
-| ------------------------------ | --------------------------------- | ------------------------------------------------------- |
-| ENVOY_IMAGE                    | `envoyproxy/envoy-alpine:v1.16.5` | Name of the Envoy Proxy image to use                    |
-| TAINT_TOLERATION_KEY           | Empty, no tolerations applied     | Toleration key to apply to gateway pods                 |
-| TAINT_TOLERATION_VALUE         | Empty, no tolerations applied     | Toleration value to apply to gateway pods               |
-| NODE_SELECTOR_KEY              | Empty, no node selector added     | Node selector label key to apply to gateway pods        |
-| NODE_SELECTOR_VALUE            | Empty, no node selector added     | Node selector label value to apply to gateway pods      |
-| ROLLING_UPDATE_MAX_UNAVAILABLE | 25%                               | Rolling Update max unavailable to apply to gateway pods |
-| ROLLING_UPDATE_MAX_SURGE       | 25%                               | Rolling Update max surge to apply to gateway pods       |
+| Variable name                  | Default                           | Description                                                               |
+| ------------------------------ | --------------------------------- | ------------------------------------------------------------------------- |
+| ENVOY_IMAGE                    | `envoyproxy/envoy-alpine:v1.16.5` | Name of the Envoy Proxy image to use                                      |
+| TAINT_TOLERATION_KEY           | Empty, no tolerations applied     | Toleration key to apply to gateway pods                                   |
+| TAINT_TOLERATION_VALUE         | Empty, no tolerations applied     | Toleration value to apply to gateway pods                                 |
+| NODE_SELECTOR_KEY              | Empty, no node selector added     | Node selector label key to apply to gateway pods                          |
+| NODE_SELECTOR_VALUE            | Empty, no node selector added     | Node selector label value to apply to gateway pods                        |
+| ROLLING_UPDATE_MAX_UNAVAILABLE | 25%                               | Rolling Update max unavailable to apply to gateway pods                   |
+| ROLLING_UPDATE_MAX_SURGE       | 25%                               | Rolling Update max surge to apply to gateway pods                         |
+| PRE_STOP_SLEEP_SECONDS         | 25                                | Number of seconds to wait before sending shutdown signal to gateway pods. `terminationGracePeriodSeconds` will be set to this value increased by 5s |

controllers/deployment.go

@@ -113,6 +113,10 @@ func deployment(es *egressv1.ExternalService, configHash string) *appsv1.Deploym
 	maxUnavailable := intstr.Parse(maxUnavailableStr)
 	maxSurge := intstr.Parse(maxSurgeStr)
 
+	preStopSleepSeconds := lookupEnvOr("PRE_STOP_SLEEP_SECONDS", "25")
+
+	terminationGracePeriodSecondsIntOrString := intstr.Parse(preStopSleepSeconds)
+
 	return &appsv1.Deployment{
 		ObjectMeta: metav1.ObjectMeta{
 			Name:        es.Name,
@@ -152,11 +156,12 @@ func deployment(es *egressv1.ExternalService, configHash string) *appsv1.Deploym
 								},
 							},
 							// Copying istio; don't try drain outbound listeners, but after going into terminating state,
-							// wait 25 seconds for connections to naturally close before going ahead with stop.
+							// wait 'preStopSleepSeconds' (default: 25) seconds for connections to naturally close before
+							// going ahead with stop.
 							Lifecycle: &corev1.Lifecycle{
 								PreStop: &corev1.Handler{
 									Exec: &corev1.ExecAction{
-										Command: []string{"/bin/sleep", "25"},
+										Command: []string{"/bin/sleep", preStopSleepSeconds},
 									},
 								},
 							},
@@ -187,7 +192,7 @@ func deployment(es *egressv1.ExternalService, configHash string) *appsv1.Deploym
 					RestartPolicy:                 corev1.RestartPolicyAlways,
 					SchedulerName:                 corev1.DefaultSchedulerName,
 					SecurityContext:               &corev1.PodSecurityContext{},
-					TerminationGracePeriodSeconds: proto.Int64(30),
+					TerminationGracePeriodSeconds: proto.Int64(int64(terminationGracePeriodSecondsIntOrString.IntValue()) + 5),
 					DNSPolicy:                     corev1.DNSDefault,
 					Volumes: []corev1.Volume{
 						{