PostgreSQL rake db:create Error in local environment - ruby-on-rails

Question

I continue to run into issues whenever I use postgreSQL for Rails app development in my local environment.
I'm running on Mac OS X 10.7. I'm aware this version comes with a pre-installed Postgres version.
I've initially installed Postgres using the brew method and have, at least a few times, found success. I'm aware of the user authentication issues.
When punching in psql --version or which psql to determine which installation is being used, I've had to adjust my .bash_profile before to reflect the appropriate path with export PATH=/usr/local/bin:$PATH.
The issue I'm running into now, and hours among hours of Google haven't solved this, is that my machine has restarted without properly closing PostgreSQL. In turn, I am getting the following error when I try to execute rake db:create on a new application, I am getting the following error:
Couldn't create database for {"adapter"=>"postgresql", "encoding"=>"unicode", "database"=>"app_development", "pool"=>5, "username"=>"tomgeoco", "password"=>nil}
could not connect to server: No such file or directory
Is the server running locally and accepting
connections on Unix domain socket "/tmp/.s.PGSQL.5432"?
My config/database.yml looks like:
development:
adapter: postgresql
encoding: unicode
database: app_development
pool: 5
username: tomgeoco
password:
test:
adapter: postgresql
encoding: unicode
database: app_development
pool: 5
username: tomgeoco
password:
production:
adapter: postgresql
encoding: unicode
database: app_development
pool: 5
username: tomgeoco
password:
When I check the status of Postgres servers with ps auxwww | grep postgre I get the following:
tomgeoco 12596 0.0 0.0 2434892 408 s000 R+ 11:54AM 0:00.00 grep postgres
So what could the problem be in this scenario?

Answer 1

This issue is not about rails but postgres. I faced with exactly the same problem recently with django project.
According to your ps output postgres isn't working at the moment.
First you have to check logs, my one is /usr/local/var/postgres/server.log. It'll give you an idea about what's wrong on postgre starting up.
My problem was solved by fixing PATH variable in .bash_profile.
Try to start your postgre server manually checking all its output. If everything goes fine but broken on system reboot, check out your launchctl daemons to find out which config file is used. This might be a problem as well.
Here you could find good instructions of clear installing of brew version of postgres. And here is modifying of postgres default settings which might be usefull as well.