You can run the Odoo instance with your own configuration file. To do so, you will need to use the -v volume option. Here is the command to run the Odoo container with the configuration file at /path/to/config/odoo.conf:
# docker run -v /path/to/config.conf:/etc/odoo -p 8069:8069 --name odoo --link db:db -t odoo
If you don't want to load the configuration file and you want to use configuration options with the command directly, then you can pass the option with -- in the command line, like this:
# docker run -p 8069:8069 --name odoo --link db:db -t odoo -- --db-filter=test