How to Fix FATAL: password authentication failed for user “postgres” in ubuntu 20.4

After a fresh installation of PostgreSQL on my machine, I was frustrated by the fact that it didn’t work seamlessly with my Django application which works perfectly on my other machine.

On running the machine I kept getting FATAL: password authentication failed for user “postgres” error, and after googling for some time I realized that most of the fixes were for one to instal pg_admin yet this seemed not right for me to add yet another installation.

So decided to dig deep to find a terminal fix to the issues. I’m pleased to share it here.

So when you run

psql -U postgres
psql: error: FATAL: Peer authentication failed for user “postgres”

To fix this run

sudo -i -u postgres
xxx@xxxx:~$ psql
psql (13.3 (Ubuntu 13.3–1.pgdg20.04+1))
Type “help” for help.

You then alter postgres user to add password postgres

postgres=# ALTER USER postgres PASSWORD ‘postgres’;
ALTER ROLE

Then exit from postgres back to the terminal user
postgres=# \q
xxxx@xxxx:~$ exit
logout

After this run sudo

sudo vi /etc/postgresql/13/main/pg_hba.conf

to change database administrative login by socker peer to md4 and any other instances of peer

Exit vim and restart postgres service with

sudo service postgresql restart

Then run

psql -U postgres

and your good to go.

Thanks