XCollector does not connect to local mysql by default on ubuntu

[rshivane]

Needs additional documentation on how to change configuration (mysql and xcollector) so that xcollector is able to connect and collect the mysql metrics

sudo mysql -e "CREATE USER 'xcollector'@'localhost' IDENTIFIED BY 'changeme';"
sudo mysql -e "GRANT PROCESS ON *.* TO 'xcollector'@'localhost';"
sudo mysql -e "GRANT SELECT ON performance_schema.* TO 'xcollector'@'localhost';"
sudo mysql -e "GRANT REPLICATION CLIENT ON *.* to 'xcollector'@'localhost';"