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SLURM Emulator Usage in Tests

How the Emulator is Used

🎯 Integration Method: PyPI Package

The SLURM emulator is available as a pip package:

```python

Clean package imports

try: import emulator EMULATOR_AVAILABLE = True except ImportError: EMULATOR_AVAILABLE = False

Import emulator components directly

from emulator.core.database import SlurmDatabase from emulator.scenarios.sequence_scenario import SequenceScenario from emulator.periodic_limits.calculator import PeriodicLimitsCalculator

```text

📦 Package Features:

  • ✅ Clean imports: No sys.path manipulation needed

  • ✅ Test dependency: Optional dependency in SLURM plugin

  • ✅ CI/CD friendly: Standard uv installation

Three Ways to Use the Emulator

1. Running API Server (Current Production Method) ✅

```bash

Start emulator API server

uvicorn emulator.api.emulator_server:app --host 0.0.0.0 --port 8080

```text

Used by: - Site agent backend in emulator mode

  • Integration tests that need HTTP API

  • Real-time scenario execution

API Endpoints: - GET /api/status - Emulator state

  • POST /api/apply-periodic-settings - Apply settings

  • POST /api/time/advance - Time manipulation

  • POST /api/usage/inject - Usage injection

2. Direct Python Import (New Testing Method) ✅

```python

Import emulator components directly

from emulator.scenarios.sequence_scenario import SequenceScenario from emulator.periodic_limits.calculator import PeriodicLimitsCalculator

Use emulator's calculation engine

calculator = PeriodicLimitsCalculator(database, time_engine) settings = calculator.calculate_periodic_settings(account)

```text

Used by: - Unit tests that need exact emulator calculations

  • Scenario validation tests

  • Performance benchmarking

Benefits: - No network overhead

  • Direct access to calculation engines

  • Can inspect internal state

3. CLI Command Interface (Available but Limited) ⚠️

```bash

Interactive CLI

python -m emulator.cli.main

Or programmatic CLI

echo "account create test-account 'Test' 1000" | python -m emulator.cli.main

```text

Used by: - Manual testing and exploration

  • Some integration tests via subprocess

Limitations: - More complex to automate

  • Harder to extract results programmatically

Test Integration Architecture

Current Test Structure ✅

```text

Plugin Tests (waldur-site-agent/plugins/slurm/tests/): │ ├── Mock Tests (Fast, No Dependencies) ✅ │ ├── Custom mock calculations │ ├── Synthetic STOMP messages │ └── Unit testing │ ├── API Integration Tests (Running Emulator) ✅ │ ├── HTTP API calls to localhost:8080 │ ├── Site agent backend ↔ emulator communication │ └── Settings verification │ └── Scenario Framework Tests (Direct Import) ✅ NEW! ├── Real emulator calculation engines ├── Built-in scenario execution └── SequenceScenario, QoSManager, PeriodicLimitsCalculator

```text

Installation Options for Different Use Cases

```bash

Install from PyPI

uv add slurm-emulator

```text

```python

Clean imports - works everywhere

try: import emulator EMULATOR_AVAILABLE = True except ImportError: EMULATOR_AVAILABLE = False

```text

Pros: - ✅ Simple pip installation

  • ✅ Clean imports (from emulator.core import ...)

  • ✅ Available system-wide

  • ✅ Proper Python package

  • ✅ Version controlled through PyPI

  • ✅ CI/CD friendly

  • ✅ No path dependencies

  • ✅ Portable across environments

Cons: - None

Option 2: Development/Test Dependency in pyproject.toml ✅ For Plugin Development

```toml

In SLURM plugin pyproject.toml

[project.optional-dependencies] test = [ "slurm-emulator", ]

```text

Installation:

```bash

Install with test dependencies

uv sync --extra test

```text

Pros: - ✅ Proper dependency management

  • ✅ Version control

  • ✅ Optional dependency (tests skip if not available)

  • ✅ Clean workspace setup

Cons: - None

Recommendation for Production

For Testing: PyPI Package ✅

```python

@pytest.mark.skipif(not EMULATOR_AVAILABLE, reason="SLURM emulator package not installed") class TestWithEmulator: @pytest.fixture(scope="class") def emulator_setup(self): # No setup needed - just import directly

1
2
    from emulator.core.database import SlurmDatabase
    # ... rest of setup

```text

Why it works well: - ✅ Optional dependency: Tests skip gracefully if emulator not installed

  • ✅ CI/CD friendly: Simple uv add slurm-emulator in CI pipeline

  • ✅ Development friendly: Standard package, easy to manage versions

  • ✅ No conflicts: Proper package management through uv

  • ✅ Clean imports: No sys.path manipulation needed

  • ✅ Portable: Works the same everywhere

For CI/CD ✅

```yaml

GitLab CI

test-with-emulator: script: - uv add slurm-emulator - uv run pytest tests/test_periodic_limits/test_emulator_scenarios_working.py

```text

For Production Deployment: API Server ✅

```bash

Run emulator as service for testing

uvicorn emulator.api.emulator_server:app --port 8080

Site agent uses HTTP API

backend_settings: periodic_limits: emulator_mode: true emulator_base_url: "http://localhost:8080"

```text

Summary

✅ Features:

  • ✅ Comprehensive testing with real emulator scenarios

  • ✅ Standard package management via uv

  • ✅ Optional emulator integration (tests skip if not installed)

  • ✅ Clean imports (no sys.path manipulation)

  • ✅ CI/CD friendly

  • ✅ Portable across environments

Test Execution Summary

```bash

Install emulator package for testing

uv add slurm-emulator

or install with test dependencies

uv sync --extra test

Run all tests (mocks + emulator scenarios)

cd plugins/slurm uv run pytest tests/test_periodic_limits/ -v

Run only emulator scenario tests

uv run pytest tests/test_periodic_limits/test_emulator_scenarios_working.py -v

Run with emulator API server

Terminal 1: Start emulator

uvicorn emulator.api.emulator_server:app --port 8080

Terminal 2: Run tests

cd plugins/slurm uv run pytest tests/test_periodic_limits/test_real_emulator_scenarios.py -v

```text

Complete emulator integration using the PyPI package ✅