I had quite some trouble to install DBD::mysql on a Ubuntu machine with MYSQL inside the Bitnami Rubystack folder. Hence here a brief description on the solution that got things working for me:

1. Follow the manual installation described here until the point:

   perl Makefile.PL.

2. Determine the path of YOUR mysql_config file, it is in the bin folder of your installation, or try to determine it with:

   whereis mysql_config

3. call:

   sudo perl Makefile.PL --mysql_config="your_mysql_path/bin/mysql_config"

4. Try to follow the instructions in #1, if an error occours that names a connection problem with:

   tmp/mysql.sock

   set an symlink as follows:

   ln -s /your_path_to_your_mysq/tmp/mysql.sock /tmp/mysql.sock

5. Try again to run make test, and u should be good to go!