The scheduler serves its own REST API from the same loop that runs executors, and the config backup spends ~21 minutes inside tarfile and zlib. Called inline that starves the loop for the whole window: the service was unreachable 03:05-03:25 every night, and again at 07:39 today when the job was triggered by hand to prove the T-69 report path. asyncio.to_thread is the fix -- zlib releases the GIL while compressing, so the loop is scheduled normally. The outage was invisible for as long as it existed. The hourly health check fires at :35 and the outage runs 03:05-03:25, so no sample ever landed inside it. A fixed-phase hourly probe cannot see a 20-minute event; that is aliasing, not bad luck, and it would have stayed hidden indefinitely. health_report.report_async joins it: psycopg2 is a blocking driver, so reporting from the loop held it for the connect and insert -- up to connect_timeout seconds precisely when the database is unreachable, which is when a report matters most. Both backup executors use it now. Caveat worth knowing: the engine wraps executors in asyncio.wait_for and a thread cannot be cancelled, so on timeout the task is recorded failed while the tar runs to completion. Still strictly better than blocking everything, and the configured 3600s is well clear of the observed 1263s. Seven tests in this file had been red since the initial commit -- they came over with the portainer-core extraction, patched the Path class wholesale, asserted "backed up" against a function returning "Backup completed: ...", and one wrapped its call in except Exception: pass with its only assertion commented out. There is no CI test gate here, so nothing reported it. Replaced with tests that build real archives in tmp_path and assert on their contents. The new loop test is the one that matters and it is mutation-checked: with to_thread reverted it counts 0 heartbeat ticks, with it ~40. Their structural demands (_create_tar_filter, a sync _cleanup_old_backups) were adopted because threading wanted that shape anyway. Their exclude semantics were not. The tests assert fnmatch behaviour and the deployed config is written against substring matching -- it excludes logs as ".log", and paths as unanchored fragments like "ollama/models/*" against members named "docker-data/ollama/...". Under fnmatch neither matches, and the nightly archive would silently gain many GB of model blobs instead of shrinking. That is now pinned by tests naming the consequence, so the "improvement" fails loudly. Co-Authored-By: Claude <noreply@anthropic.com>
Scheduler Tests
Comprehensive test suite for The Scheduler using pytest.
Test Structure
tests/
├── conftest.py # Shared fixtures and configuration
├── test_api.py # API endpoint tests
├── test_example_executor.py # Example executor tests
├── test_doc_sync_executor.py # Documentation sync executor tests
└── README.md # This file
Running Tests
Run all tests
docker exec scheduler pytest
Run with coverage report
docker exec scheduler pytest --cov=src --cov-report=term-missing
Run specific test file
docker exec scheduler pytest tests/test_api.py
Run specific test class
docker exec scheduler pytest tests/test_api.py::TestHealthEndpoint
Run specific test
docker exec scheduler pytest tests/test_api.py::TestHealthEndpoint::test_health_endpoint_returns_healthy
Run tests by marker
# Run only unit tests
docker exec scheduler pytest -m unit
# Run only API tests
docker exec scheduler pytest -m api
# Run only executor tests
docker exec scheduler pytest -m executor
# Run only fast tests (exclude slow)
docker exec scheduler pytest -m "not slow"
Run with verbose output
docker exec scheduler pytest -v
Run with detailed failure output
docker exec scheduler pytest -vv --tb=long
Stop on first failure
docker exec scheduler pytest -x
Test Markers
Tests are organized with pytest markers:
@pytest.mark.unit- Fast unit tests with no external dependencies@pytest.mark.integration- Integration tests (may use database)@pytest.mark.api- API endpoint tests@pytest.mark.executor- Task executor tests@pytest.mark.slow- Tests that take a while to run
Coverage Reports
After running tests with coverage:
- Terminal: Shows missing lines in terminal output
- HTML: Open
htmlcov/index.htmlin browser for detailed report - JSON: Machine-readable coverage data in
coverage.json
View HTML coverage report:
# From host machine
open /home/jpmschweitzer/docker-data/scheduler/htmlcov/index.html
Writing New Tests
Test File Naming
- Test files must start with
test_ - Place in
tests/directory - Use descriptive names:
test_<module_name>.py
Test Function Naming
- Test functions must start with
test_ - Use descriptive names:
test_<what_is_being_tested>
Using Fixtures
Fixtures are defined in conftest.py:
def test_something(test_settings, auth_headers):
# Use fixtures as function parameters
assert test_settings.app_name == "Test Scheduler"
Adding Markers
@pytest.mark.unit
@pytest.mark.api
def test_health_endpoint(client):
response = client.get("/health")
assert response.status_code == 200
Async Tests
@pytest.mark.asyncio
async def test_async_function():
result = await some_async_function()
assert result is not None
Mocking
from unittest.mock import patch, MagicMock
def test_with_mock():
with patch('module.function') as mock_func:
mock_func.return_value = "mocked"
result = call_function_that_uses_it()
assert result == "mocked"
Continuous Integration
These tests are designed to run in CI pipelines:
# Example GitHub Actions
- name: Run tests
run: |
docker exec scheduler pytest --cov=src --cov-report=xml
docker exec scheduler pytest --cov=src --cov-report=html
Test Database
Tests use mocked database connections by default. For integration tests that require a real database:
- Set up a test database
- Use
POSTGRES_DB=test_schedulerenvironment variable - Run migrations before tests
- Clean up after tests
Troubleshooting
Tests fail with "ModuleNotFoundError"
# Install test dependencies
docker exec scheduler /venv/bin/pip install -r requirements.txt
Tests fail with database errors
- Tests use mocked connections by default
- Check that mocks are properly set up in conftest.py
- For integration tests, ensure test database exists
Coverage not working
# Reinstall pytest-cov
docker exec scheduler /venv/bin/pip install --upgrade pytest-cov
Best Practices
- Fast by default: Unit tests should be fast (<1s each)
- Isolated: Tests should not depend on each other
- Descriptive: Test names should clearly describe what they test
- Single assertion: Test one thing per test when possible
- Use fixtures: Reuse common setup via fixtures
- Mock external deps: Don't hit real databases/APIs in unit tests
- Mark appropriately: Use markers to categorize tests
Current Coverage
Run this to see current coverage:
docker exec scheduler pytest --cov=src --cov-report=term
Target: 80%+ code coverage for critical paths