fix cluster quorum size calculation and tests

Author: sircthulhu

api/v1alpha1/etcdcluster_types.go

@@ -17,8 +17,6 @@ limitations under the License.
 package v1alpha1
 
 import (
-	"math"
-
 	corev1 "k8s.io/api/core/v1"
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 	"k8s.io/apimachinery/pkg/util/intstr"
@@ -84,12 +82,7 @@ type EtcdCluster struct {
 
 // CalculateQuorumSize returns minimum quorum size for current number of replicas
 func (r *EtcdCluster) CalculateQuorumSize() int {
-	replicas := *r.Spec.Replicas
-	if replicas%2 == 0 {
-		replicas = replicas + 1
-	}
-
-	return int(math.Ceil(float64(replicas) / 2.))
+	return int(*r.Spec.Replicas)/2 + 1
 }
 
 // +kubebuilder:object:root=true

api/v1alpha1/etcdcluster_types_test.go

@@ -0,0 +1,22 @@
+package v1alpha1
+
+import (
+	. "github.com/onsi/ginkgo/v2"
+	. "github.com/onsi/gomega"
+	"k8s.io/utils/ptr"
+)
+
+var _ = Context("CalculateQuorumSize", func() {
+	It("should return correct result for odd number of replicas", func() {
+		etcdCluster := EtcdCluster{
+			Spec: EtcdClusterSpec{Replicas: ptr.To(int32(3))},
+		}
+		Expect(etcdCluster.CalculateQuorumSize()).To(Equal(2))
+	})
+	It("should return correct result for even number of replicas", func() {
+		etcdCluster := EtcdCluster{
+			Spec: EtcdClusterSpec{Replicas: ptr.To(int32(4))},
+		}
+		Expect(etcdCluster.CalculateQuorumSize()).To(Equal(3))
+	})
+})