Mysql – Unknown MySQL server host – connection problem

Do not mess with the mysql db. There is a lot more going on there than just the users table. Your best bet is the "SHOW GRANTS FOR" command. I have a lot of CLI maintenance aliases and functions in my .bashrc (actually my .bash_aliases that I source in my .bashrc). This function:

mygrants()
{
  mysql -B -N $@ -e "SELECT DISTINCT CONCAT(
    'SHOW GRANTS FOR \'', user, '\'@\'', host, '\';'
    ) AS query FROM mysql.user" | \
  mysql $@ | \
  sed 's/\(GRANT .*\)/\1;/;s/^\(Grants for .*\)/## \1 ##/;/##/{x;p;x;}'
}

The first mysql command uses SQL to generate valid SQL which is piped to the second mysql command. The output is then piped through sed to add pretty comments.

The $@ in the command will allow you to call it as: mygrants --host=prod-db1 --user=admin --password=secret

You can use your full unix tool kit on this like so:

mygrants --host=prod-db1 --user=admin --password=secret | grep rails_admin | mysql --host=staging-db1 --user=admin --password=secret

That is THE right way to move users. Your MySQL ACL is modified with pure SQL.

This should work:

ssh -L 3310:127.0.0.1:3306 user@server

The first port number is the local port to use (must not be in use already), the IP in between the colons is the IP to connect to, from the perspective of the host you are sshing into. The second port number is the port to connect to. If you are connecting to a server other than the one you are sshing into, then try the following:

ssh -L 3310:<remote-IP>:3306 user@server

Usually, when I want to do this more than one time, I create an entry in ~/.ssh/config like the following where sshhost.example.com is the server I am sshing to, the local port I want to open is 5910, the IP on the other side I want to connect to is 192.168.35.69, and the port I want to connect to there is 5900:

Host desk
    Hostname sshhost.example.com
    User jed
    Port 22
    LocalForward 5910 192.168.35.69:5900

Then from a command prompt I can just do

jed@jed-mbp:~$ ssh desk

and get a tunnel to my desktop at the office.

Good luck,

--jed