Fix: PostgreSQL 18 PGDATA path (initdb fails with old /data path)

[sandvale]

Summary

PostgreSQL 18 changed its default data directory structure.
The Sailbox installer still mounts /var/lib/postgresql/data, which causes initdb to fail and PostgreSQL never starts.

Problem

The official PostgreSQL 18 Docker image no longer uses /var/lib/postgresql/data.
Data is now initialized under:

/var/lib/postgresql

Because the installer mounts the old path, the container starts but PostgreSQL immediately exits with an initialization error.

Fix

Updated the docker-compose template to mount the correct directory:

Before:

• sailbox_pgdata:/var/lib/postgresql/data

After:

• sailbox_pgdata:/var/lib/postgresql

Result

After applying this fix, PostgreSQL initializes correctly and Sailbox starts without errors.

Environment

• Ubuntu 24.04
• Docker CE latest
• PostgreSQL 18-alpine
• Installer from https://get.sailbox.dev

[sandvale]

This PR fixes the PostgreSQL 18 initialization issue by updating the PGDATA mount path.
Postgres 18 no longer uses /var/lib/postgresql/data, so the installer fails without this change.

[ZhonFortune]

same issue. But the author seems like no longer maintenance this project ever