Cannot run rake db:reset

# https://stackoverflow.com/questions/28116927/postgres-permission-denied-to-create-database-on-rake-dbcreateall
I have faced same issues when running rake db:test:prepare in postgresql on my Ruby on Rails project. This is pretty clear from the error message, that its a permission issue for the user. I added CREATEDB permission for new_user as following from the console.

To access postgres console:

$ sudo -u postgres -i

postgres@host:~$ psql
In there:

postgres=# ALTER USER new_user CREATEDB;
It's working perfect for now. You may have another issues with database ownership, for this you can change database privileges and owner as following command.

postgres=# GRANT ALL PRIVILEGES ON  DATABASE database_name to new_user;
postgres=# ALTER DATABASE database_name owner to new_user;

then
sudo service postgresql restart

then 
rake db:reset