Why I get the error: Ident authentication failed for user 'abelard' under Cent OS 6, PostgreSQL 9.4

Rails
1

All config files described here are the same as my Mac OS’s and all
works
fine in Mac OS.

I got the same error in CentOS 6 x86_64:

Ident authentication failed for user 'abelard'

When running the following two commands:

1. rake db:create
2. psql -d testforabelard2 -U abelard -h localhost

I got the same error after trying these answers
1 and
2.

My /var/lib/pgsql/9.4/pg_hba.con’s content is as follows:

local   all             all

trust
host all all 127.0.0.1/32
trust
host all all ::1/128
trust
And there is a blank file /var/lib/pgsql/9.4/pg_ident.con

My database.yml’s content is as follows:

development:
  adapter: postgresql
  encoding: unicode
  database: social_stream_development
  pool: 5
  username: abelard
  password: password

And for offering the same params as my Mac OS’s, I altered
PostgreSQL’s
user abelard :

testforabelard2=# \du
            List of roles
 Role name | Attributes  | Member of
-----------+-------------+-----------
 abelard   | Superuser   | {}
           : Create role
           : Create DB
 postgres  | Superuser   | {}
           : Create role
           : Create DB

And I can run the command without -h localhost successfully:

psql -d testforabelard2 -U abelard

I don’t know what things I miss, any advice will be welcome!