K8SPSMDB-1571: Make reconciliation interval configurable (#2221)

* feat: Make reconciliation interval configurable

* review

* review

---------

Co-authored-by: Viacheslav Sarzhan <slava.sarzhan@percona.com>

Author: adutra

deploy/bundle.yaml

@@ -26807,6 +26807,8 @@ spec:
               value: percona-server-mongodb-operator
             - name: RESYNC_PERIOD
               value: 5s
+            - name: RECONCILE_INTERVAL
+              value: 5s
             - name: DISABLE_TELEMETRY
               value: "false"
             - name: MAX_CONCURRENT_RECONCILES

deploy/cw-bundle.yaml

@@ -26833,6 +26833,8 @@ spec:
               value: percona-server-mongodb-operator
             - name: RESYNC_PERIOD
               value: 5s
+            - name: RECONCILE_INTERVAL
+              value: 5s
             - name: DISABLE_TELEMETRY
               value: "false"
             - name: MAX_CONCURRENT_RECONCILES

deploy/cw-operator.yaml

@@ -54,6 +54,8 @@ spec:
               value: percona-server-mongodb-operator
             - name: RESYNC_PERIOD
               value: 5s
+            - name: RECONCILE_INTERVAL
+              value: 5s
             - name: DISABLE_TELEMETRY
               value: "false"
             - name: MAX_CONCURRENT_RECONCILES

deploy/operator.yaml

@@ -56,6 +56,8 @@ spec:
               value: percona-server-mongodb-operator
             - name: RESYNC_PERIOD
               value: 5s
+            - name: RECONCILE_INTERVAL
+              value: 5s
             - name: DISABLE_TELEMETRY
               value: "false"
             - name: MAX_CONCURRENT_RECONCILES

pkg/controller/perconaservermongodb/psmdb_controller.go

@@ -99,7 +99,7 @@ func newReconciler(mgr manager.Manager) (reconcile.Reconciler, error) {
 		client:                 client,
 		scheme:                 mgr.GetScheme(),
 		serverVersion:          sv,
-		reconcileIn:            time.Second * 5,
+		reconcileIn:            getReconcileInterval(),
 		crons:                  NewCronRegistry(),
 		lockers:                newLockStore(),
 		newPBM:                 backup.NewPBM,
@@ -140,6 +140,32 @@ func getOperatorPodImage(ctx context.Context) (string, error) {
 	return pod.Spec.Containers[0].Image, nil
 }
 
+// getReconcileInterval returns the reconciliation interval from the RECONCILE_INTERVAL
+// environment variable, or the default of 5 seconds if not set or invalid.
+func getReconcileInterval() time.Duration {
+	defaultInterval := 5 * time.Second
+
+	interval := os.Getenv("RECONCILE_INTERVAL")
+	if interval == "" {
+		return defaultInterval
+	}
+
+	d, err := time.ParseDuration(interval)
+	if err != nil {
+		log := logf.Log.WithName("psmdb-controller")
+		log.Info("Invalid RECONCILE_INTERVAL value, using default (5s)", "value", interval, "error", err, "default", defaultInterval)
+		return defaultInterval
+	}
+
+	if d < defaultInterval {
+		log := logf.Log.WithName("psmdb-controller")
+		log.Info("RECONCILE_INTERVAL must be at least 5s, using 5s", "value", interval, "default", defaultInterval)
+		return defaultInterval
+	}
+
+	return d
+}
+
 // add adds a new Controller to mgr with r as the reconcile.Reconciler
 func add(mgr manager.Manager, r reconcile.Reconciler) error {
 	return builder.ControllerManagedBy(mgr).

pkg/controller/perconaservermongodb/psmdb_controller_test.go

@@ -2,9 +2,14 @@ package perconaservermongodb
 
 import (
 	"context"
+	"os"
+	"testing"
+	"time"
 
 	. "github.com/onsi/ginkgo/v2"
 	. "github.com/onsi/gomega"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
 	corev1 "k8s.io/api/core/v1"
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 	"k8s.io/apimachinery/pkg/types"
@@ -13,6 +18,67 @@ import (
 	psmdbv1 "github.com/percona/percona-server-mongodb-operator/pkg/apis/psmdb/v1"
 )
 
+func TestGetReconcileInterval(t *testing.T) {
+	tests := []struct {
+		name     string
+		envValue string
+		setEnv   bool
+		want     time.Duration
+	}{
+		{
+			name:   "unset",
+			setEnv: false,
+			want:   5 * time.Second,
+		},
+		{
+			name:     "valid duration",
+			envValue: "30s",
+			setEnv:   true,
+			want:     30 * time.Second,
+		},
+		{
+			name:     "invalid duration falls back to default",
+			envValue: "invalid",
+			setEnv:   true,
+			want:     5 * time.Second,
+		},
+		{
+			name:     "zero duration falls back to default",
+			envValue: "0s",
+			setEnv:   true,
+			want:     5 * time.Second,
+		},
+		{
+			name:     "negative duration falls back to default",
+			envValue: "-5s",
+			setEnv:   true,
+			want:     5 * time.Second,
+		},
+		{
+			name:     "duration less than 5s falls back to default",
+			envValue: "1s",
+			setEnv:   true,
+			want:     5 * time.Second,
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			defer func() {
+				err := os.Unsetenv("RECONCILE_INTERVAL")
+				require.NoError(t, err)
+			}()
+			if tt.setEnv {
+				err := os.Setenv("RECONCILE_INTERVAL", tt.envValue)
+				require.NoError(t, err)
+			}
+
+			got := getReconcileInterval()
+			assert.Equal(t, tt.want, got)
+		})
+	}
+}
+
 var _ = Describe("PerconaServerMongoDB", Ordered, func() {
 	ctx := context.Background()
 	const ns = "psmdb"