Implement preStop lifecycle handler

Author: kurtmc

internal/controller/scripts/pre_stop.sh

@@ -0,0 +1,32 @@
+#!/bin/sh
+
+set -e
+
+VALKEY_ROLE="$(valkey-cli -c info replication 2>/dev/null | awk '/^role:/ { print $1 }' | tr -d '\r')"
+
+if [ "${VALKEY_ROLE}" != "role:master" ]; then
+	echo "ROLE IS NOT MASTER"
+	exit 0
+fi
+
+CONNTECTED_SLAVES="$(valkey-cli -c info replication | awk -F: '/^connected_slaves:/ { print $2 }')"
+
+if [ "$CONNTECTED_SLAVES" -le "0" ]; then
+	echo "Connected slaves is 0, therefore nothing to do"
+	exit 0
+fi
+
+SLAVE0="$(valkey-cli -c info replication | awk -F: '/^slave0:/ { print $2 }')"
+SLAVE_IP="$(echo "${SLAVE0}" | tr , '\n' | awk -F= '/^ip/ { print $2 }')"
+SLAVE_PORT="$(echo "${SLAVE0}" | tr , '\n' | awk -F= '/^port/ { print $2 }')"
+SLAVE_STATUS="$(echo "${SLAVE0}" | tr , '\n' | awk -F= '/^state/ { print $2 }')"
+if [ "${SLAVE_STATUS}" != "online" ]; then
+	echo "Slave status is $SLAVE_STATUS, therefore nothing to do"
+	exit 0
+fi
+
+echo "Pause writes"
+valkey-cli -c CLIENT PAUSE "5000" WRITE
+
+valkey-cli -h "${SLAVE_IP}" -p "${SLAVE_PORT}" -c cluster failover
+sleep 3s

internal/controller/valkey_controller.go

@@ -390,6 +390,11 @@ func (r *ValkeyReconciler) upsertConfigMap(ctx context.Context, valkey *hyperv1.
 		logger.Error(err, "failed to read ping_liveness_local.sh")
 		return err
 	}
+	preStop, err := scripts.ReadFile("scripts/pre_stop.sh")
+	if err != nil {
+		logger.Error(err, "failed to read pre_stop.sh")
+		return err
+	}
 	cm := &corev1.ConfigMap{
 		ObjectMeta: metav1.ObjectMeta{
 			Name:      valkey.Name,
@@ -400,6 +405,7 @@ func (r *ValkeyReconciler) upsertConfigMap(ctx context.Context, valkey *hyperv1.
 			"valkey.conf":             conf.String(),
 			"ping_readiness_local.sh": string(pingReadinessLocal),
 			"ping_liveness_local.sh":  string(pingLivenessLocal),
+			"pre_stop.sh":             string(preStop),
 		},
 	}
 	if valkey.Spec.TLS {
@@ -2342,6 +2348,17 @@ func (r *ValkeyReconciler) upsertStatefulSet(ctx context.Context, valkey *hyperv
 									},
 								},
 							},
+							Lifecycle: &corev1.Lifecycle{
+								PreStop: &corev1.LifecycleHandler{
+									Exec: &corev1.ExecAction{
+										Command: []string{
+											"sh",
+											"-c",
+											"/scripts/pre_stop.sh",
+										},
+									},
+								},
+							},
 							Resources: getResourceRequirements(valkey),
 							VolumeMounts: []corev1.VolumeMount{
 								{