Install Postgres on Cent OS.

Update System Packages:

sudo yum update

Install PostgreSQL:

 
sudo yum install postgresql-server

Initialize the Database:

sudo postgresql-setup initdb

Start and Enable PostgreSQL Service:

 
sudo systemctl start postgresql
sudo systemctl enable postgresql

Then finally setup according to the below description to enable publish access.

sudo nano /var/lib/pgsql/data/pg_hba.conf

Make sure the following line is uncommented or added:

host    all             all             0.0.0.0/0               md5

sudo nano /var/lib/pgsql/data/postgresql.conf

Find the line that starts with listen_addresses and change its value to '*':

listen_addresses = '*'

Restart PostgreSQL:

sudo systemctl restart postgresql

Configure Firewall:

If you have a firewall enabled, you need to allow incoming connections on the PostgreSQL port (default is 5432):

sudo firewall-cmd --zone=public --add-port=5432/tcp --permanent
sudo firewall-cmd --reload

Switch to the postgres user:

 
sudo su - postgres

Peer authentication works if the system user matches the PostgreSQL role. Switch to the postgres system user and then connect:

 
sudo -i -u postgres
 
psql

 
ALTER USER postgres WITH PASSWORD 'postgres_password';

Exit the PostgreSQL prompt:

\q

Switch back to your regular user account:

exit

Now you are ready to login