Introduce configurable parameters for ES client node draining

Add new configuration options to manage the draining of nodes in the Elasticsearch client within the ES-operator project. These settings include the number of retries and the minimum and maximum wait times for retries, enhancing the flexibility and control over the node draining process.

- ESClientDrainingRetry: Sets the number of retries for draining operations.
- ESClientDrainingMinWaitTime: Defines the minimum wait time between retry attempts.
- ESClientDrainingMaxWaitTime: Specifies the maximum wait time between retry attempts.

These parameters allow operators to tailor the draining behavior based on specific needs and conditions of their Elasticsearch clusters, ensuring more effective and reliable operations.

main.go

@@ -7,6 +7,7 @@ import (
 	"net/url"
 	"os"
 	"os/signal"
+	"strconv"
 	"syscall"
 	"time"
 
@@ -21,27 +22,33 @@ import (
 )
 
 const (
-	defaultInterval           = "10s"
-	defaultAutoscalerInterval = "30s"
-	defaultMetricsAddress     = ":7979"
-	defaultClientGoTimeout    = 30 * time.Second
-	defaultClusterDNSZone     = "cluster.local."
+	defaultInterval                    = "10s"
+	defaultAutoscalerInterval          = "30s"
+	defaultMetricsAddress              = ":7979"
+	defaultClientGoTimeout             = 30 * time.Second
+	defaultClusterDNSZone              = "cluster.local."
+	defaultESClientDrainingRetry       = 999
+	defaultESClientDrainingMinWaitTime = 10 * time.Second
+	defaultESClientDrainingMaxWaitTime = 30 * time.Second
 )
 
 var (
 	config struct {
-		Interval              time.Duration
-		AutoscalerInterval    time.Duration
-		APIServer             *url.URL
-		PodSelectors          Labels
-		PriorityNodeSelectors Labels
-		MetricsAddress        string
-		ClientGoTimeout       time.Duration
-		Debug                 bool
-		OperatorID            string
-		Namespace             string
-		ClusterDNSZone        string
-		ElasticsearchEndpoint *url.URL
+		Interval                    time.Duration
+		AutoscalerInterval          time.Duration
+		APIServer                   *url.URL
+		PodSelectors                Labels
+		PriorityNodeSelectors       Labels
+		MetricsAddress              string
+		ClientGoTimeout             time.Duration
+		Debug                       bool
+		OperatorID                  string
+		Namespace                   string
+		ClusterDNSZone              string
+		ElasticsearchEndpoint       *url.URL
+		ESClientDrainingRetry       int
+		ESClientDrainingMinWaitTime time.Duration
+		ESClientDrainingMaxWaitTime time.Duration
 	}
 )
 
@@ -69,6 +76,12 @@ func main() {
 		Default(defaultClusterDNSZone).StringVar(&config.ClusterDNSZone)
 	kingpin.Flag("elasticsearch-endpoint", "The Elasticsearch endpoint to use for reaching Elasticsearch API. By default the service endpoint for the EDS is used").
 		URLVar(&config.ElasticsearchEndpoint)
+	kingpin.Flag("elasticsearch-client-draining-retry", "Number of retries for node draining in Elasticsearch client in case of errors").
+		Default(strconv.Itoa(defaultESClientDrainingRetry)).IntVar(&config.ESClientDrainingRetry)
+	kingpin.Flag("elasticsearch-client-draining-min-wait-time", "Minimum wait time between retry attempts during node draining in Elasticsearch client").
+		Default(defaultESClientDrainingMinWaitTime.String()).DurationVar(&config.ESClientDrainingMinWaitTime)
+	kingpin.Flag("elasticsearch-client-draining-max-wait-time", "Maximum wait time between retry attempts during node draining in Elasticsearch client").
+		Default(defaultESClientDrainingMaxWaitTime.String()).DurationVar(&config.ESClientDrainingMaxWaitTime)
 	kingpin.Flag("namespace", "Limit operator to a certain namespace").
 		Default(v1.NamespaceAll).StringVar(&config.Namespace)