Service Postgres

Service: Postgres

Image	${POSTGRES_IMAGE} = postgres:17 (pinned major; the servarr wiki warns against latest)
Container	arrs-postgres
Profile	always on
Port	not published (uncomment ports: + POSTGRES_HOST_PORT for pgAdmin etc.)
Volume	${APPDATA}/postgres:/var/lib/postgresql/data, ./postgres/initdb:/docker-entrypoint-initdb.d:ro
Healthcheck	pg_isready -U $POSTGRES_USER -d postgres every 10 s

Environment

Variable	From .env	Purpose
POSTGRES_USER	POSTGRES_USER	superuser / owner of every app database
POSTGRES_PASSWORD	POSTGRES_PASSWORD
POSTGRES_DB	${POSTGRES_USER}	the entrypoint's default database (unused by the apps)
ARR_APPS	${COMPOSE_PROFILES}	read by 01-create-arr-dbs.sh

Databases created

postgres/initdb/01-create-arr-dbs.sh runs on first cluster init and can be re-run any time:

docker compose exec postgres /docker-entrypoint-initdb.d/01-create-arr-dbs.sh

Profile	Databases
radarr, sonarr, lidarr (also readarr, prowlarr, whisparr)	<app>, <app>-log
bazarr	bazarr
seerr	seerr
qbittorrent, sabnzbd, nzbget	none

The apps create their own schema on first connect. wranglarr dumps each database with pg_dump -Fc --no-owner and restores with pg_restore --clean --if-exists --single-transaction.

Useful commands

docker compose exec postgres psql -U "$POSTGRES_USER" -l
docker compose exec postgres psql -U "$POSTGRES_USER" -d radarr -c '\dt'
docker compose exec postgres psql -U "$POSTGRES_USER" -c "SELECT datname, pg_size_pretty(pg_database_size(datname)) FROM pg_database"

Updates and major upgrades

Minor releases within the pinned major (17.2 → 17.3) are ordinary container updates: wranglarr backs up every suite with databases, swaps the container on the same data directory, and waits until Postgres accepts connections.

A major upgrade (17 → 18) changes the on-disk format, so a container swap would leave Postgres unable to read its data directory. wranglarr detects it (the image's PG_MAJOR changes), refuses, and blocks that image. To do one deliberately, use wranglarr's dumps:

1. In wranglarr, Backup now on every suite that has databases.
2. docker compose stop, then move appdata/postgres aside (keep it until the upgrade has proven itself).
3. Set POSTGRES_IMAGE=postgres:18 in .env. Check that image's notes for data directory changes before you start it.
4. docker compose up -d postgres wranglarr. The init script creates empty databases for every enabled profile.
5. In wranglarr, restore each app from the version you took in step 1, with databases only. Then docker compose up -d.