Enable the mysqld_exporter without any required user changes

Signed-off-by: Matt Lord <[email protected]>

Author: mattlord

pkg/operator/vttablet/constants.go

@@ -32,6 +32,7 @@ const (
 
 	mysqldExporterContainerName      = "mysqld-exporter"
 	mysqldExporterCommand            = "/bin/mysqld_exporter"
+	mysqldExporterMySQLCnf           = "client.cnf"
 	mysqldExporterUser               = "vt_dba"
 	mysqldExporterPort               = 9104
 	mysqldExporterPortName           = "metrics"

pkg/operator/vttablet/mysqlctld.go

@@ -40,6 +40,7 @@ ln -sf /dev/stderr /mnt/vt/config/stderr.symlink
 echo "log-error = /vt/config/stderr.symlink" > /mnt/vt/config/mycnf/log-error.cnf
 echo "binlog_format=row" > /mnt/vt/config/mycnf/rbr.cnf
 echo "socket = ` + mysqlSocketPath + `" > /mnt/vt/config/mycnf/socket.cnf
+echo -n "[client]\nuser=vt_dba\nsocket=` + mysqlSocketPath + `\n" > /mnt/vt/config/mycnf/client.cnf
 `
 
 	mysqlSocketInitScript = `set -ex

pkg/operator/vttablet/pod.go

@@ -17,6 +17,7 @@ limitations under the License.
 package vttablet
 
 import (
+	"path/filepath"
 	"strconv"
 	"strings"
 
@@ -256,6 +257,10 @@ func UpdatePod(obj *corev1.Pod, spec *Spec) {
 		if spec.MysqldExporter != nil && (len(spec.MysqldExporter.Resources.Limits) > 0 || len(spec.MysqldExporter.Resources.Requests) > 0) {
 			update.ResourceRequirements(&mysqldExporterContainer.Resources, &spec.MysqldExporter.Resources)
 		}
+
+		if _, ok := spec.MysqldExporter.ExtraFlags["config.my-cnf"]; !ok {
+			spec.MysqldExporter.ExtraFlags["config.my-cnf"] = filepath.Join(vtMycnfPath, mysqldExporterMySQLCnf)
+		}
 	}
 
 	// Set the resource requirements on each of the default vttablet init