From 2e20c17faf83aa6d9c8f57bedaaf9d591acdb855 Mon Sep 17 00:00:00 2001
From: acekingke <aceking.ke@gmail.com>
Date: Wed, 18 Oct 2023 16:25:20 +0800
Subject: [PATCH] *: add leader to follower choice

---
 api/v1alpha1/mysqlcluster_types.go                     |  5 +++++
 api/v1beta1/mysqlcluster_types.go                      |  5 +++++
 api/v1beta1/zz_generated.conversion.go                 |  2 ++
 .../templates/mysql.radondb.com_mysqlclusters.yaml     | 10 ++++++++++
 config/crd/bases/mysql.radondb.com_mysqlclusters.yaml  | 10 ++++++++++
 mysqlcluster/syncer/follower_service.go                |  5 ++++-
 6 files changed, 36 insertions(+), 1 deletion(-)

diff --git a/api/v1alpha1/mysqlcluster_types.go b/api/v1alpha1/mysqlcluster_types.go
index 4d7be6c6..50ffb146 100644
--- a/api/v1alpha1/mysqlcluster_types.go
+++ b/api/v1alpha1/mysqlcluster_types.go
@@ -117,6 +117,11 @@ type MysqlClusterSpec struct {
 	// Bootstraping from remote data source
 	// +optional
 	SourceConfig *corev1.SecretProjection `json:"sourceConfig,omitempty"`
+
+	// Leader as follower represents if make leader use as follower to read
+	// +optional
+	// +kubebuilder:default:=false
+	LeaderAsFollower bool `json:"leaderAsfollower,omitempty"`
 }
 
 // ReadOnly define the ReadOnly pods
diff --git a/api/v1beta1/mysqlcluster_types.go b/api/v1beta1/mysqlcluster_types.go
index dd4576ef..5b88c887 100644
--- a/api/v1beta1/mysqlcluster_types.go
+++ b/api/v1beta1/mysqlcluster_types.go
@@ -149,6 +149,11 @@ type MysqlClusterSpec struct {
 	// Specification of the service that exposes the MySQL leader instance.
 	// +optional
 	Service *ServiceSpec `json:"service,omitempty"`
+
+	// Leader as follower represents if make leader use as follower to read
+	// +optional
+	// +kubebuilder:default:=false
+	LeaderAsFollower bool `json:"leaderAsfollower,omitempty"`
 }
 
 // ReadOnly define the ReadOnly pods
diff --git a/api/v1beta1/zz_generated.conversion.go b/api/v1beta1/zz_generated.conversion.go
index 506979ed..d5f01fcb 100644
--- a/api/v1beta1/zz_generated.conversion.go
+++ b/api/v1beta1/zz_generated.conversion.go
@@ -432,6 +432,7 @@ func autoConvert_v1beta1_MysqlClusterSpec_To_v1alpha1_MysqlClusterSpec(in *Mysql
 	// WARNING: in.EnableAutoRebuild requires manual conversion: does not exist in peer-type
 	// WARNING: in.Log requires manual conversion: does not exist in peer-type
 	// WARNING: in.Service requires manual conversion: does not exist in peer-type
+	out.LeaderAsFollower = in.LeaderAsFollower
 	return nil
 }
 
@@ -455,6 +456,7 @@ func autoConvert_v1alpha1_MysqlClusterSpec_To_v1beta1_MysqlClusterSpec(in *v1alp
 	// WARNING: in.BackupScheduleJobsHistoryLimit requires manual conversion: does not exist in peer-type
 	// WARNING: in.TlsSecretName requires manual conversion: does not exist in peer-type
 	// WARNING: in.SourceConfig requires manual conversion: does not exist in peer-type
+	out.LeaderAsFollower = in.LeaderAsFollower
 	return nil
 }
 
diff --git a/charts/mysql-operator/templates/mysql.radondb.com_mysqlclusters.yaml b/charts/mysql-operator/templates/mysql.radondb.com_mysqlclusters.yaml
index 4da8fd8e..d33b4f89 100644
--- a/charts/mysql-operator/templates/mysql.radondb.com_mysqlclusters.yaml
+++ b/charts/mysql-operator/templates/mysql.radondb.com_mysqlclusters.yaml
@@ -101,6 +101,11 @@ spec:
                 description: Lagged
                 format: int32
                 type: integer
+              leaderAsfollower:
+                default: false
+                description: Leader as follower represents if make leader use as follower
+                  to read
+                type: boolean
               metricsOpts:
                 default:
                   enabled: false
@@ -3598,6 +3603,11 @@ spec:
                 description: Lagged
                 format: int32
                 type: integer
+              leaderAsfollower:
+                default: false
+                description: Leader as follower represents if make leader use as follower
+                  to read
+                type: boolean
               logOpts:
                 description: LogOpts is the options of log settings.
                 properties:
diff --git a/config/crd/bases/mysql.radondb.com_mysqlclusters.yaml b/config/crd/bases/mysql.radondb.com_mysqlclusters.yaml
index 40d731dd..fdbbdd2f 100644
--- a/config/crd/bases/mysql.radondb.com_mysqlclusters.yaml
+++ b/config/crd/bases/mysql.radondb.com_mysqlclusters.yaml
@@ -83,6 +83,11 @@ spec:
                 description: Lagged
                 format: int32
                 type: integer
+              leaderAsfollower:
+                default: false
+                description: Leader as follower represents if make leader use as follower
+                  to read
+                type: boolean
               metricsOpts:
                 default:
                   enabled: false
@@ -3580,6 +3585,11 @@ spec:
                 description: Lagged
                 format: int32
                 type: integer
+              leaderAsfollower:
+                default: false
+                description: Leader as follower represents if make leader use as follower
+                  to read
+                type: boolean
               logOpts:
                 description: LogOpts is the options of log settings.
                 properties:
diff --git a/mysqlcluster/syncer/follower_service.go b/mysqlcluster/syncer/follower_service.go
index b2f9f3d2..7f965456 100644
--- a/mysqlcluster/syncer/follower_service.go
+++ b/mysqlcluster/syncer/follower_service.go
@@ -48,7 +48,10 @@ func NewFollowerSVCSyncer(cli client.Client, c *mysqlcluster.MysqlCluster) synce
 			service.Spec.Type = "ClusterIP"
 		}
 		service.Spec.Selector = c.GetSelectorLabels()
-		service.Spec.Selector["role"] = string(utils.Follower)
+
+		if !c.Spec.LeaderAsFollower {
+			service.Spec.Selector["role"] = string(utils.Follower)
+		}
 		service.Spec.Selector["healthy"] = "yes"
 
 		if len(service.Spec.Ports) != 2 {