psql: error: connection to server on socket “/var/run/postgresql/.s.PGSQL.5432” failed: FATAL: Peer authentication failed for user “postgres” (Ubuntu)

Question

You can edit your .conf files with privileges using an editor, for my case it is nano.

$sudo nano /etc/postgresql/14/main/pg_ident.conf

Map your user by adding this line

# MAPNAME       SYSTEM-USERNAME         PG-USERNAME
user1           <computer-username>     postgres

Replace the <computer-username> with the System-Username, which can be found using the whoami command. Type in your terminal:

$whoami

Then go ahead to the pg_hba.conf with privileges

$sudo nano /etc/postgresql/14/main/pg_hba.conf

Add your postgres user, with method=peer, as shown below:

# TYPE  DATABASE        USER            ADDRESS                 METHOD
local   all             postgres                                peer

This worked for me.