今天安装openstack folsom版本，安装完mysql，为各个服务增加对应的数据库和用户后，发现
无法使用新增的用户登陆mysql。我增加用户的方法如下：
mysql -uroot -p$MYSQL_PASS <<EOF
CREATE DATABASE nova;
GRANT ALL PRIVILEGES ON nova.* TO 'nova'@'%' IDENTIFIED BY '$MYSQL_PASS';
CREATE DATABASE glance;
GRANT ALL PRIVILEGES ON glance.* TO 'glance'@'%' IDENTIFIED BY '$MYSQL_PASS';
CREATE DATABASE keystone;
GRANT ALL PRIVILEGES ON keystone.* TO 'keystone'@'%'IDENTIFIED BY '$MYSQL_PASS';
CREATE DATABASE cinder;
GRANT ALL PRIVILEGES ON cinder.* TO 'cinder'@'%'IDENTIFIED BY '$MYSQL_PASS';
CREATE DATABASE quantum;
GRANT ALL PRIVILEGES ON quantum.* TO 'quantum'@'%'IDENTIFIED BY '$MYSQL_PASS';
FLUSH PRIVILEGES;
EOF
但使用用户登陆失败：
root@controller:~# mysql -h localhost -ukeystone -ppassword
ERROR 1045 (28000): Access denied for user 'keystone'@'localhost' (using password: YES)
解决方法：
增加普通用户后，执行：
mysql> use mysql
mysql> delete from user where user='';
mysql> flush privileges;
意思是删除匿名用户。
OK，搞定，enjoy！