"Peer authentication failed for user lemmy"

[mtekman]

This is an issue to do with the postgresql using peer authentication and not password ("md5") authentication.

Solution

The solution is to create a relevant line in your pg_hba.conf file (usually found in /etc/postgresql/).

Change:

# "local" is for Unix domain socket connections only
local   all             all                                     peer

to:

# "local" is for Unix domain socket connections only
local   lemmy           lemmy                                   md5
local   all             all                                     peer

Or, one liner:

sed -i -r '/^local\s+all\s+all\s+peer/i local lemmy lemmy md5' /etc/postgresql/15/main/pg_hba.conf

Commentary

This ensures that only the "lemmy" database under user "lemmy" accepts passwords.
Note that this new line must be added above the unedited line, in order for it to work.

After this, restart your postgres (sudo systemctl restart postgresql), and things should work

[Nutomic]

#221