PostgreSQL Major Upgrade

This guide is for the PostgreSQL container from PLANKA's docker-compose.yml. PLANKA works with PostgreSQL 15 or newer, so nothing forces you to do this until your version reaches end of life.

If you run PostgreSQL yourself, follow the PostgreSQL upgrade documentation.

danger

Do not just change the image tag. A major version cannot read the data directory of another one: the container keeps restarting with database files are incompatible with server. Your data is not lost, and setting the old tag again brings it back.

Create a backup before you start.

The commands below go from 16 to 18. From the folder with your docker-compose.yml:

Export All Databases

docker compose exec -T postgres pg_dumpall -U postgres > planka-postgres.sql

Stop the Stack
```
docker compose down
```
Do not add -v: that would delete the volumes.
Edit docker-compose.yml

Change the image and give it a new volume:
```
services:
  postgres:
    image: postgres:18-alpine
    volumes:
      - db-data-18:/var/lib/postgresql

volumes:
  data:
  db-data:
  db-data-18:
```
warning
Starting with PostgreSQL 18, the image expects its volume at /var/lib/postgresql. For 17 and older, keep /var/lib/postgresql/data.
Start PostgreSQL and Import
```
docker compose up -d --wait postgres
docker compose exec -T postgres psql -U postgres < planka-postgres.sql
```
Two errors are expected and harmless: role "postgres" already exists and database "planka" already exists.
Start PLANKA
```
docker compose up -d
```
Clean Up

Once you have checked that everything is there, remove the export and the old volume. The volume name starts with your Compose project name:
```
rm planka-postgres.sql
docker volume rm planka_db-data
```
Remove db-data: from your docker-compose.yml afterwards.