Validating password length

go/logic/applier.go

@@ -200,7 +200,7 @@ func (this *Applier) CreateChangelogTable() error {
 			id bigint auto_increment,
 			last_update timestamp not null DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
 			hint varchar(64) charset ascii not null,
-			value varchar(255) charset ascii not null,
+			value varchar(4096) charset ascii not null,
 			primary key(id),
 			unique key hint_uidx(hint)
 		) auto_increment=256

go/logic/inspect.go

@@ -192,6 +192,9 @@ func (this *Inspector) inspectOriginalAndGhostTables() (err error) {
 
 // validateConnection issues a simple can-connect to MySQL
 func (this *Inspector) validateConnection() error {
+	if len(this.connectionConfig.Password) > mysql.MaxReplicationPasswordLength {
+		return fmt.Errorf("MySQL replication length limited to 32 characters. See https://dev.mysql.com/doc/refman/5.7/en/assigning-passwords.html")
+	}
 	query := `select @@global.port, @@global.version`
 	var port int
 	if err := this.db.QueryRow(query).Scan(&port, &this.migrationContext.InspectorMySQLVersion); err != nil {

go/mysql/utils.go

@@ -17,6 +17,7 @@ import (
 )
 
 const MaxTableNameLength = 64
+const MaxReplicationPasswordLength = 32
 
 type ReplicationLagResult struct {
 	Key InstanceKey

localtests/fail-password-length/create.sql

@@ -0,0 +1,7 @@
+drop table if exists gh_ost_test;
+create table gh_ost_test (
+  id int auto_increment,
+  i int not null,
+  ts timestamp,
+  primary key(id)
+) auto_increment=1;

localtests/fail-password-length/expect_failure

@@ -0,0 +1 @@
+MySQL replication length limited to 32 characters

localtests/fail-password-length/extra_args

@@ -0,0 +1 @@
+--password="0123456789abcdefghij0123456789abcdefghijxx"