max reconciles workerqueue (#299)

chart/values.yaml

@@ -6,7 +6,8 @@ env:
   DENY_LIST: "default,kube-system" # Comma-separated list of namespaces to ignore
   RECONCILE_WAIT: "10s"            # Reconciliation delay
   WATCH_NAMESPACE: ""              # Namespace to watch or empty string to watch all namespaces, To watch multiple namespaces add , into string. Ex: WATCH_NAMESPACE: "ns1,ns2,ns3"
-
+  #MAX_CONCURRENT_RECONCILES:: ""  # MaxConcurrentReconciles is the maximum number of concurrent Reconciles which can be run.
+
 replicaCount: 1
 
 image:

controllers/druid/druid_controller.go

@@ -12,6 +12,7 @@ import (
 	"k8s.io/apimachinery/pkg/runtime"
 	ctrl "sigs.k8s.io/controller-runtime"
 	"sigs.k8s.io/controller-runtime/pkg/client"
+	"sigs.k8s.io/controller-runtime/pkg/controller"
 	"sigs.k8s.io/controller-runtime/pkg/reconcile"
 
 	druidv1alpha1 "github.com/druid-io/druid-operator/apis/druid/v1alpha1"
@@ -74,6 +75,9 @@ func (r *DruidReconciler) SetupWithManager(mgr ctrl.Manager) error {
 	return ctrl.NewControllerManagedBy(mgr).
 		For(&druidv1alpha1.Druid{}).
 		WithEventFilter(GenericPredicates{}).
+		WithOptions(controller.Options{
+			MaxConcurrentReconciles: getMaxConcurrentReconciles(),
+		}).
 		Complete(r)
 }
 
@@ -91,3 +95,13 @@ func LookupReconcileTime() time.Duration {
 		return v
 	}
 }
+
+func getMaxConcurrentReconciles() int {
+	var MaxConcurrentReconciles = "MAX_CONCURRENT_RECONCILES"
+
+	nu, found := os.LookupEnv(MaxConcurrentReconciles)
+	if !found {
+		return 1
+	}
+	return Str2Int(nu)
+}

controllers/druid/util.go

@@ -3,6 +3,7 @@ package druid
 import (
 	"os"
 	"reflect"
+	"strconv"
 	"strings"
 )
 
@@ -66,3 +67,13 @@ func boolFalse() *bool {
 	bool := false
 	return &bool
 }
+
+// to be used in max concurrent reconciles only
+// defaulting to return 1
+func Str2Int(s string) int {
+	i, err := strconv.Atoi(s)
+	if err != nil {
+		return 1
+	}
+	return i
+}