如何在远程机器上连接postgres和ruby

I am on remote machine with CentOS with an IP and my postgres is on different IP. I want to access postgres with my rails server. I edited the database.yml file and installed gem pg and included host IP in database.yml file.. But I am unable to run the rake db:migrate and rails server.. It shows PG ERROR as below.Help me to solve this . I am trying to connect to server from past 4 days..but I cant... when i run db:migrate it show sthe following error.I am on remote machine with CentOS with an IP a