K8SPXC-1071 - Set default value for proxysql scheduler

Author: tplavcic

pkg/apis/pxc/v1/pxc_types.go

@@ -737,6 +737,10 @@ func (cr *PerconaXtraDBCluster) CheckNSetDefaults(serverVersion *version.ServerV
 			c.ProxySQL.ImagePullPolicy = corev1.PullAlways
 		}
 
+		if len(c.ProxySQL.Scheduler) == 0 {
+			c.ProxySQL.Scheduler = "percona"
+		}
+
 		c.ProxySQL.VolumeSpec.reconcileOpts()
 
 		if len(c.SSLSecretName) > 0 {

pkg/pxc/queries/queries.go

@@ -313,13 +313,12 @@ func (p *Database) PresentInHostgroups(host string) (bool, error) {
 
 func (p *Database) PrimaryHost(scheduler string) (string, error) {
 	var host string
-	var writerID int
+
+	// value of writer group is hardcoded in ProxySQL config inside docker image
+	// https://github.com/percona/percona-docker/blob/pxc-operator-1.3.0/proxysql/dockerdir/etc/proxysql-admin.cnf#L23
+	var writerID = 11
 	if scheduler == "percona" {
 		writerID = 100
-	} else {
-		// value of writer group is hardcoded in ProxySQL config inside docker image
-		// https://github.com/percona/percona-docker/blob/pxc-operator-1.3.0/proxysql/dockerdir/etc/proxysql-admin.cnf#L23
-		writerID = 11
 	}
 
 	err := p.db.QueryRow("SELECT hostname FROM runtime_mysql_servers WHERE hostgroup_id = ?", writerID).Scan(&host)