fix(#1591): Fixes schema connection for RunPython migration steps

[igor-petrik-invitae]

Fixes #1591

Description of the Change

Adds use of schema_editor connection for RunPython migrations, as recommended by Django.

Checklist

• PR only contains one change (considered splitting up PR)
• unit-test added
• documentation updated (N/A?)
• CHANGELOG.md updated (only for user relevant changes) (N/A?)
• author name in AUTHORS
• tests/app/idp updated to demonstrate new features (N/A?)
• tests/app/rp updated to demonstrate new features (N/A?)

[Copilot]

Pull request overview

This PR addresses Django’s guidance for RunPython migrations by ensuring data migrations use the schema_editor connection (rather than implicitly using the default DB connection), which helps prevent multi-DB connection/locking issues like the hang reported in #1591.

Changes:

• Update RunPython migration functions to query/save using schema_editor.connection.alias.
• Add a new tox environment to run migrations against a non-default database configuration.
• Add contributor to AUTHORS.

Reviewed changes

Copilot reviewed 5 out of 5 changed files in this pull request and generated 2 comments.

Show a summary per file

File	Description
tox.ini	Adds migrate_non_default tox env to exercise migrations on a non-default DB alias.
tests/non_default_db_settings.py	Introduces settings intended to validate migration behavior when using --database=secondary.
oauth2_provider/migrations/0012_add_token_checksum.py	Uses schema_editor DB alias for iteration and saves in RunPython.
oauth2_provider/migrations/0006_alter_application_client_secret.py	Uses schema_editor DB alias for queryset and saves in RunPython.
AUTHORS	Adds a new author entry.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.

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[dopry]

@igor-petrik-invitae Thanks for the PR! I was giving it a review. When I check out the first commit, the migration is failing on 0006_.... Are we sure this is truly replicating the issue for migration 0012_... and not exposing a a different, but valid bug, in migrations handling of multiple databases?

[igor-petrik-invitae]

I want to point out that this is not multiple databases; the point of the test is to test different where the connection used for migrations is a different connection to the same database.

You are right, that 0006 does not fail on my Postgres database, where 0012 does. I was not sure how to write a test in this repository that would use a postgres database, but if you take the same config as here and substitute a postgres database instead of a sqlite database, that should reproduce the original deadlock issue.

[dopry]

If you're at all interested in setting up the tests with postgres we need to cover local and CI environmnts.
For local I tend use docker compose. Here is a subset of one of my projects.. It's single instance not multiple instance...
docker-compose.yml

# re-usable yaml anchors
x-task: &task
  # docker stack deploy restart policy for tasks
  deploy:
    restart_policy:
      condition: on-failure
    replicas: 1
  # docker compose stand-alone restart policy for tasks
  restart: on-failure

x-task-ensure-database: &task-ensure-database
  <<: *task
  image: postgres:15
  entrypoint: |
    sh -c "
    echo $PGPASSWORD;
    psql -v ON_ERROR_STOP=0 --host postgres --username \"$${POSTGRES_USER}\" <<EOSQL
      CREATE ROLE $${DB_NAME} LOGIN PASSWORD '$${DB_PASS}';
      CREATE DATABASE $${DB_NAME};
      GRANT ALL ON DATABASE $${DB_NAME} TO $${DB_NAME};
    EOSQL"
  # you must set the following environment variables where you use this anchor.
  # environment:
    # - POSTGRES_USER
    # - PGPASSWORD=${POSTGRES_PASS:-jangl}
    # - DB_NAME=service
    # - DB_PASS=password

volumes:
  postgres-data:

services:
  # a postgres container for providing database access.
  postgres:
    image: postgres:15
    environment:
      - POSTGRES_USER=postgres
      - POSTGRES_PASSWORD=password
    ports:
      - "5432:5432"
    volumes:
      - postgres-data:/var/lib/postgresql/data

ensure-db-alpha:
    <<: *task-ensure-database
    environment:
      - PGPASSWORD=password
      - POSTGRES_USER=postgres
      - DB_NAME=alpha
      - DB_PASS=password
    depends_on:
      - postgres

in CI you can add postgres to the workflow with the services key. I set it up on another project I work on a while back wagtail-grapple. I would love to have testing on postgres.. there are quite a few issues that never surface when testing soley with sqlite.

[dopry]

@igor-petrik-invitae I've added postgres primary/replica testing to our test environments. that should provide a better baseline for testing this feature. Do you have time to update this PR?

[Copilot]

Pull request overview

Copilot reviewed 7 out of 7 changed files in this pull request and generated 3 comments.

[Copilot]

Pull request overview

Copilot reviewed 5 out of 5 changed files in this pull request and generated no new comments.