Volume bind mount path changed with postgres v18

When setting up a complete new pgbackweb stack with your provided compose example, I get the following error: ``` $ docker compose up [+] Running 3/3 ✔ Network pgbackweb_default Created 0.1s ✔ Container postgres Created 0.1s ✔ Container pgbackweb Created 0.0s Attaching to pgbackweb, postgres postgres | Error: in 18+, these Docker images are configured to store database data in a postgres | format which is compatible with "pg_ctlcluster" (specifically, using postgres | major-version-specific directory names). This better reflects how postgres | PostgreSQL itself works, and how upgrades are to be performed. postgres | postgres | See also https://github.com/docker-library/postgres/pull/1259 postgres | postgres | Counter to that, there appears to be PostgreSQL data in: postgres | /var/lib/postgresql/data (unused mount/volume) postgres | postgres | This is usually the result of upgrading the Docker image without postgres | upgrading the underlying database using "pg_upgrade" (which requires both postgres | versions). postgres | postgres | The suggested container configuration for 18+ is to place a single mount postgres | at /var/lib/postgresql which will then place PostgreSQL data in a postgres | subdirectory, allowing usage of "pg_upgrade --link" without mount point postgres | boundary issues. postgres | postgres | See https://github.com/docker-library/postgres/issues/37 for a (long) postgres | discussion around this process, and suggestions for how to do so. postgres exited with code 1 dependency failed to start: container postgres exited (1) ``` In your example compose file with postgres v18, the volume bind mount path in the container is wrong. With postgres v18, it changed from `/var/lib/postgresql/data` to `/var/lib/postgresql`. After changing it, the database starts successfully. ``` $ docker compose up [...] pgbackweb-db | 2025-11-14 20:54:42.081 UTC [1] LOG: database system is ready to accept connections ```