docker-compose-light: Examples DB init fails

[bschreder]

Bug description

Execute docker compose -f docker-compose-light.yml up --build

First issue:
During the "Init Step 4/4 [Starting] -- Loading examples"

superset-init-light-1 | 2026-03-07 19:39:39,685:WARNING:superset.commands.database.utils:Error processing catalog 'examples'
superset-init-light-1 | return dialect.connect(*cargs, **cparams)
superset-init-light-1 | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
superset-init-light-1 | File "/app/.venv/lib/python3.11/site-packages/sqlalchemy/engine/default.py", line 598, in connect
superset-init-light-1 | return self.dbapi.connect(*cargs, **cparams)
superset-init-light-1 | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
superset-init-light-1 | File "/app/.venv/lib/python3.11/site-packages/psycopg2/init.py", line 122, in connect
superset-init-light-1 | conn = _connect(dsn, connection_factory=connection_factory, **kwasync)
superset-init-light-1 | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
superset-init-light-1 | psycopg2.OperationalError: could not translate host name "db" to address: Name or service not known

fails to load the example database. the issue is the compose file labels the db service as db-light and the environment variable for EXAMPLES_HOST and EXAMPLES_DB isn't set.

The second issue: the examples user isn't created in the meta database.
When trying to login as examples user, the login fails

The fix is to provide the database on the psql command that creates the example user.

Screenshots/recordings

No response

Superset version

master / latest-dev

Python version

3.11

Node version

18 or greater

Browser

Chrome

Additional context

No response

Checklist

• I have searched Superset docs and Slack and didn't find a solution to my problem.
• I have searched the GitHub issue tracker and didn't find a similar bug report.
• I have checked Superset's logs for errors and if I found a relevant Python stacktrace, I included it here as text in the "additional context" section.

[dosubot]

Hi @bschreder! I'm Dosu and I’m helping the superset team.

Thanks for reporting this! Your analysis of the issues is correct. Looking at the history:

1. EXAMPLES_HOST issue: The docker-compose-light.yml names the database service db-light, but the EXAMPLES_HOST environment variable defaults to db. This causes the hostname resolution error you're seeing. The fix is to set EXAMPLES_HOST=db-light.

2. Examples user creation: The examples-init.sh script creates the user, and as you noted, the psql command needs the proper database context.

Interestingly, PR #37645 previously identified these exact issues with docker-compose-light.yml, but that PR was closed without being merged. The original design in PR #34324 intended to use DuckDB for examples instead of PostgreSQL, which would have avoided the user creation issue entirely.

If you have a fix ready, a PR addressing both the EXAMPLES_HOST configuration and the examples user creation would be welcome!

To reply, just mention @dosu.

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[bschreder]

Closing this issue — the project already resolved this in #34324. See related PR #38492.

[bschreder]

Closing this issue — resolved by #34324. See related PR #38492.