Advice on setting up Nominatim with other, non-admin user -- www-data keeps coming up

[hadjiprocopis]

I am trying to setup Nominatim locally (and thank you very much for this free and open source software) but with a (reasonable) twist: I would like to have a new Pg user which is not admin to own this DB.

Following the guide here for the common Pg admin postgres, as a start, has failed: https://nominatim.org/release-docs/latest/admin/Advanced-Installations/

NOMINATIM_DATABASE_DSN='pgsql:dbname=nominatim;user=postgres' nominatim import --prepare-database

Using project directory: /var/www/nominatim-server
2025-12-11 14:08:40: Creating database
2025-12-11 14:08:40: Web user 'www-data' does not exist. Create it with:
      createuser www-data
2025-12-11 14:08:40: FATAL: Missing read-only user.

So it still uses the dreaded www-data user and that user is a Pg-related one, because createuser is a Pg command.

I have also tried it with my own simple Pg user (e.g. osm) with the same results( osm because ideally I would like one user (osm) to own all OSM dbs, tiles etc.)

Additionally, it would be very convenient for me to use ENV variables PGSERVICE and PGSERVICEFILE so as not to pass the DSN with a password (eventually because of my automated script, it should contain the password) around.
Is there such support already? I have not found it, but that's not important.

The good news is that if I create a Pg user www-data, then the command nominatim import --prepare-database succeeds. In the worst case perhaps I can start with this user and when all is setup I can transfer ownership to my own user?

10min Edit: well the command which works is actually: sudo -u postgres nominatim import --prepare-database (so as to run it as Pg admin). However, as I said asking for postgres password will break my automated pipeline. In this case for psql commands I usually I do PGSERVICEFILE="credentialsfile" PGSERVICE='postgres' psql. OK but the command PGSERVICEFILE="credentialsfile" PGSERVICE='postgres' NOMINATIM_DATABASE_DSN="pgsql:dbname=nominatim;user=www-data" nominatim import ... fails, most likely confused.

Anyway, creating Nominatim db with other users I think is important but since I can setup the server even without this feature, it is ok for me, so don't waste much time on it.

[mtmail]

For the .env file the default value for NOMINATIM_DATABASE_WEBUSER is www-data https://nominatim.org/release-docs/latest/customize/Settings/ I think you can set it to osm. It's separate accounts because usually people want a super user (permission to create and delete databases) and a read-only user.

The NOMINATIM_DATABASE_DSN syntax allows many settings https://www.postgresql.org/docs/current/libpq-connect.html#LIBPQ-CONNSTRING-URIS I think you'd need to set service=nominatim and then in your pg_service.conf file have a section with that name. I'm not familiar where the default file location of that file is and how the PGSERVICEFILE environment variable can overwrite that location.

[hadjiprocopis]

Thank you for sharing this, I thought it was for the webserver only.

Secondly, I have now got it working. The documentation is correct but I have misread the first command's db user. So now I use:

# in the documentation "user=dbadmin" is "user=postgres" not
# the user I want to own the Nominatim DB
NOMINATIM_DATABASE_DSN="pgsql:dbname=nominatim;user=postgres" nominatim import --prepare-database
# then grant as postgres, here is how I use the PGSERVICEFILE
# note Pg user "_osm" is the user I want to own Nominatim DB (and all OSM-related DBs)
PGSERVICEFILE=./credentials-postgres.pg PGSERVICE=postgres psql -d nominatim -c 'CREATE USER "_osm"' -c 'GRANT CREATE ON SCHEMA public TO "_osm"'
# and now continue the DB import
NOMINATIM_DATABASE_DSN="pgsql:dbname=nominatim;user=_osm" nominatim import --continue import-from-file --osm-file monaco.latest.pbf

[lonvia]

Great that you got it working. Just wanted to add: as Nominatim is based on libpq, it will also respect any PG_* environment variables that you set. In fact, internally it only uses environment variables to configure database parameter for subprocesses. If you only want to work with environment variables, then set NOMINATIM_DATABASE_DSN="pgsql:".

[hadjiprocopis]

Got it, thank you @lonvia , @mtmail ++