MongoDB Container Testing

Why MongoDB?

✅ Perfect for document-based data, flexible schema, and modern web applications. Great for chaos testing in CI/CD pipelines.

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✅ Test Cases Implemented

✅ Test Case 1 — Check MongoDB Version

Verifies the container is running and accessible.

client = mongo.get_connection_client()
db = client.admin
result = db.command("serverStatus")
assert "version" in result

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✅ Test Case 2 — Insert and Query Document

Tests basic document insertion and retrieval.

db = client.test_db
collection = db.users
result = collection.insert_one({"name": "Alice", "age": 30})
assert result.inserted_id is not None

doc = collection.find_one({"name": "Alice"})
assert doc["age"] == 30

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✅ Test Case 3 — Insert Multiple Documents

Inserts multiple documents and confirms count.

collection = db.users
docs = [{"name": "Bob"}, {"name": "Charlie"}]
result = collection.insert_many(docs)
assert len(result.inserted_ids) == 2

count = collection.count_documents({})
assert count == 3

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✅ Test Case 4 — Update Document

Tests document update functionality.

collection = db.users
collection.update_one({"name": "Alice"}, {"$set": {"age": 31}})
doc = collection.find_one({"name": "Alice"})
assert doc["age"] == 31

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✅ Test Case 5 — Delete Documents

Removes documents and verifies deletion.

collection = db.users
collection.delete_many({})
count = collection.count_documents({})
assert count == 0

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✅ How to Run the Tests

Run:

pytest -v testcontainers/test_mongodb_container.py

✅ Expected:

5 passed in X.XXs

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✅ Useful Commands

• Check running containers:

bash docker ps

• View MongoDB logs:

bash docker logs <container_id>

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🧪 Chaos Testing Scenarios

✅ Scenario 1: Connection Failures

def test_mongodb_connection_failure():
    """Test that our app handles MongoDB connection failures gracefully"""
    with MongoDbContainer("mongo:6.0") as mongo:
        # Simulate connection failure
        mongo.get_docker_client().stop(mongo.get_container_id())

        # Verify our app handles the failure
        with pytest.raises(Exception):
            mongo.get_connection_client()

✅ Scenario 2: Large Document Handling

def test_mongodb_large_document():
    """Test that our app handles large documents in MongoDB"""
    with MongoDbContainer("mongo:6.0") as mongo:
        client = mongo.get_connection_client()
        db = client.test_db
        collection = db.large_docs

        # Create large document
        large_doc = {"data": "x" * 10000, "id": 1}

        # Insert and verify
        result = collection.insert_one(large_doc)
        assert result.inserted_id is not None

        # Retrieve and verify
        doc = collection.find_one({"id": 1})
        assert len(doc["data"]) == 10000

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📊 Monitoring & Reporting

✅ Generate HTML Report

pytest testcontainers/test_mongodb_container.py --html=reports/mongodb-test-report.html --self-contained-html

✅ View Container Logs

# Get container ID
docker ps | grep mongo

# View logs
docker logs <container_id>

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