Password authentication failing for Postgresql - ruby-on-rails

Question

I'm creating a Rails app and using a Postgresql database with it. I've created a few tables and a user, core, which is the owner of each of the tables.
postgres=# create user core with password 'n7zD5FG5';
CREATE ROLE
postgres=# create database core_apps_prod with owner core;
CREATE DATABASE
postgres=# create database core_apps_dev with owner core;
CREATE DATABASE
postgres=# create database core_apps_test with owner core;
CREATE DATABASE
And my database.yml file:
development:
adapter: postgresql
database: core_apps_dev
username: core
password: n7zD5FG5
host: localhost
However, when I run rake db:migrate, I get the error
rake aborted!
FATAL: password authentication failed for user "core"
I also cannot connect to psql manually: psql -U core -W -d core_apps_dev - I get the same error.
How can I allow core to connect to Postgresql on localhost?
The output of SELECT * FROM pg_roles where rolname='core'; is:
rolname | rolsuper | rolinherit | rolcreaterole | rolcreatedb | rolcatupdate | rolcanlogin | rolreplication | rolconnlimit | rolpassword | rolvaliduntil | rolconfig | oid
---------+----------+------------+---------------+-------------+--------------+-------------+----------------+--------------+-------------+---------------+-----------+-------
core | f | t | f | f | f | t | f | -1 | ******** | | | 16392

Answer 1

You need to add privileges to the role when you create it. To allow logging in and using rake db:create use the following:
create role core with login createdb password 'n7zD5FG5';
To fix your problem, try altering the role to allow login:
alter role core with login;
And if that doesn't work, see if making the login valid forever works:
alter role core valid until 'infinity';
More about roles: http://www.postgresql.org/docs/8.2/static/sql-createrole.html
Edit:
I also had to do this when I installed postgres:
$ psql postgres -c 'CREATE EXTENSION "adminpack";'

Answer 2

The issue turned out to be an issue with the port. The Postgresql Activerecord adapter defaults to port 5432, while the port in my configuration was port 5433. My database.yml now looks like this:
development:
adapter: postgresql
database: core_apps_dev
username: core
password: n7zD5FG5
host: localhost
port: 5433

Answer 3

The newly created user probably is lacking database privileges. There are many different privileges you can give to a user.
Assuming that you have admin account access to psql, go into psql and run
GRANT ALL PRIVILEGES ON DATABASE core_apps_dev to core;

Answer 4

Can you please try
alter role core with password "n7zD5FG5";