To reset postgresql database password
-------------------------------------

# example below uses vaultwarden as the app with db user "vaultwarden" and db name "vaultwarden"
# all commands are executed from docker shell

# stop vaultwarden
cd /opt/stacks/vaultwarden
docker compose down

# Edit pg_hba.conf
nano /mnt/data/vaultwarden/pgdata/pg_hba.conf

# at the bottom of the file, comment out "host all all all scram-sha-256" and add new line "host all all all trust"
# result should look as follows:
# -- snip --
 # host all all all scram-sha-256
 host all all all trust
# -- snip --

# start postgresql
cd /opt/stacks/vaultwarden
docker compose up -d postgresql

# exec into vaultwarden-postgresql-1
docker exec -it vaultwarden-postgresql-1 bash

# open psql shell
psql -U vaultwarden -d vaultwarden

# update password for "vaultwarden" user; "ALTER ROLE" should be returned
ALTER USER vaultwarden WITH PASSWORD 'new_password';

# (optional) ensure that "vaultwarden" user owns "vaultwarden" database
ALTER DATABASE vaultwarden OWNER TO vaultwarden

# quit psql shell
\q

# exit to docker shell
exit

# restore pg_hba.conf
nano /mnt/data/vaultwarden/pgdata/pg_hba.conf

# at the bottom of the file, uncomment out "host all all all scram-sha-256" and remove line "host all all all trust"
# result should look as follows:
# -- snip --
 host all all all scram-sha-256
# -- snip --

# start vaultwarden
cd /opt/stacks/vaultwarden
docker compose up -d