dashboard history: clean up dashboard version history

pkg/setting/setting.go

@@ -89,6 +89,9 @@ var (
 	SnapShotTTLDays       int
 	SnapShotRemoveExpired bool
 
+	// Dashboard history
+	DashboardVersionsToKeep int
+
 	// User settings
 	AllowUserSignUp         bool
 	AllowUserOrgCreate      bool
@@ -518,6 +521,10 @@ func NewConfigContext(args *CommandLineArgs) error {
 	SnapShotRemoveExpired = snapshots.Key("snapshot_remove_expired").MustBool(true)
 	SnapShotTTLDays = snapshots.Key("snapshot_TTL_days").MustInt(90)
 
+	// read dashboard settings
+	dashboards := Cfg.Section("dashboards")
+	DashboardVersionsToKeep = dashboards.Key("snapshot_TTL_days").MustInt(20)
+
 	//  read data source proxy white list
 	DataProxyWhiteList = make(map[string]bool)
 	for _, hostAndIp := range util.SplitString(security.Key("data_source_proxy_whitelist").String()) {