Map root user to Postgres user

I had a chance to map Linux users to Postgres. Recently I have started to understand the PostgreSQL’s internal processing. One of the topics explained about the pg_ident.conf file. Till that time I never used that file, even I didn’t hear about that. Basically, this file will help you to connect with PostgreSQL from any System users. I have configured everything to connect PostgreSQL from root user, but still, couldn’t able to connect. Because I used psql command to connect.

root@sqladmin#psql psql
FATAL: role "root" does not exist

I have wasted 2 days for this. Then I found one solution in StackOverflow that I should mention the PostgreSQL username in the command. Here is the configurations to map any Linux users to PostgreSQL.

In this blog, I have mapped my root user. Edit the pg_ident.conf file and add the below line.

# MAPNAME SYSTEM-USERNAME PG-USERNAME
mapping_root root postgres

** MAPNAME**: A friendly name for your mapping. SYSTEM-USERNAME: Name of the system user that wants to map. PG-USERNAME: Name of the PostgreSQL user that the Linux user should connect. Edit the pg_hba.conf file to enable this mapping

# TYPE DATABASE USER ADDRESS METHOD
local all postgres peer
# -- add mapping configs.
local all postgres peer map=mapping_root

Restart your PostgreSQL or Reload it. Now you should enter the below command to connect PostgreSQL via root user

root@sqladmin#psql

I have tested this on PostgreSQL 9.6.