To upgrade postgresql
---------------------

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

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

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

# dump database
cd /opt/stacks/vaultwarden
mkdir /mnt/data/vaultwarden/pgbackups/$(date -I)
docker exec vaultwarden-postgresql-1 pg_dumpall -U vaultwarden > /mnt/data/vaultwarden/pgbackups/$(date -I)/vaultwarden-backup.sql
chown -R postgres:postgres /mnt/data/vaultwarden/pgbackups/$(date -I)
chmod -R 700 /mnt/data/vaultwarden/pgbackups/$(date -I)

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

# rename pgdata (we don't delete yet; in order to have a rollback option)
# in Truenas shell, enter
zfs rename SSD1/docker/data/vaultwarden/pgdata SSD1/docker/data/vaultwarden/pgdata-old

# create new pgdata dataset
# in Truenas shell, enter
zfs create SSD1/docker/data/vaultwarden/pgdata
chown -R postgres:postgres /mnt/SSD1/docker/data/vaultwarden/pgdata
chmod 700 /mnt/SSD1/docker/data/vaultwarden/pgdata

# edit the vaultwarden compose.yml file to the new version of the postgresql image
# -- snip --
  postgresql:
    image: postgres:17-alpine
# -- snip --

# pull image
docker compose pull

# start new postgresql container
docker compose up -d postgresql

# import database dump
cat /mnt/data/vaultwarden/pgbackups/$(date -I)/vaultwarden-backup.sql | docker exec -i vaultwarden-postgresql-1 psql -U vaultwarden

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

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

# Check if all is ok
# Log into vaultwarden as check if all looks ok
# If ok, delete the pgdata-old dataset using Truenas GUI, or later (after confidence is high enough)