Adding additional DynamoDB CRUD Lambda pytest

python-test-samples/README.md

@@ -14,6 +14,7 @@ This portion of the repository contains code samples for testing serverless appl
 |[API Gateway with Lambda and DynamoDB](./apigw-lambda-dynamodb)|This project contains unit and integration tests for a pattern using API Gateway, AWS Lambda and Amazon DynamoDB.|
 |[Schema and Contract Testing](./schema-and-contract-testing)|This project contains sample schema and contract tests for an event driven architecture.|
 |[Kinesis with Lambda and DynamoDB](./kinesis-lambda-dynamodb)|This project contains a example of testing an application with an Amazon Kinesis Data Stream.|
+|[DynamoDB CRUD with Lambda Local](./dynamodb-crud-lambda-local)|This project contains unit pytest running CRUD operations using lambda functions and DynamoDB on local Docker containers.|
 |[SQS with Lambda](./apigw-sqs-lambda-sqs)|This project demonstrates testing SQS as a source and destination in an integration test|
 |[Step Functions Local](./step-functions-local)| An example of testing Step Functions workflow locally using pytest and Testcontainers | 
 

python-test-samples/dynamodb-crud-lambda-local/README.md

@@ -0,0 +1,194 @@
+# Testing Workflow - PyTest que Replica SAM CLI Manual
+
+## 🚀 Setup y Ejecución (Workflow Limpio)
+
+### **Prerequisitos**
+- Docker running
+- AWS SAM CLI instalado
+- Python 3.10+
+
+### **1. Preparar el Entorno**
+
+```bash
+# Navegar al directorio del proyecto
+cd dynamodb-crud-lambda-local
+
+# Build SAM application
+cd tests
+sam build
+
+# Verificar build exitoso
+ls .aws-sam/build/  # Debería mostrar las 5 funciones Lambda
+```
+
+### **2. Iniciar DynamoDB Local (FUERA de PyTest)**
+
+```bash
+# Iniciar DynamoDB Local con network host
+docker run --rm -d --name dynamodb-local --network host amazon/dynamodb-local
+
+# Verificar que esté corriendo
+curl http://localhost:8000/  # Debería responder
+```
+
+### **3. Configurar Variables de Entorno**
+
+```bash
+# En el directorio tests/
+export AWS_ACCESS_KEY_ID='DUMMYIDEXAMPLE'
+export AWS_SECRET_ACCESS_KEY='DUMMYEXAMPLEKEY'
+export AWS_REGION='us-east-1'
+```
+
+### **4. Setup Python Environment**
+
+```bash
+# Crear y activar virtual environment
+python3 -m venv venv
+source venv/bin/activate
+
+# Instalar dependencias
+pip install --upgrade pip
+pip install -r requirements.txt
+```
+
+### **5. Ejecutar Tests**
+
+```bash
+# Ejecutar todos los tests
+python3 -m pytest -s unit/src/test_lambda_dynamodb_local.py
+
+# Ejecutar test específico
+python3 -m pytest -s unit/src/test_lambda_dynamodb_local.py::test_lambda_create_function
+
+# Ejecutar con verbose output
+python3 -m pytest -s -v unit/src/test_lambda_dynamodb_local.py
+```
+
+### **6. Cleanup**
+
+```bash
+# Limpiar Python environment
+deactivate
+rm -rf venv/
+
+# Limpiar variables
+unset AWS_ACCESS_KEY_ID
+unset AWS_SECRET_ACCESS_KEY
+unset AWS_REGION
+
+# Parar DynamoDB container
+docker stop dynamodb-local
+```
+
+## 📊 Output Esperado (Limpio)
+
+```
+=================== test session starts ===================
+platform linux -- Python 3.10.12, pytest-8.4.1
+collected 7 items
+
+unit/src/test_lambda_dynamodb_local.py 
+DynamoDB Local is running on port 8000
+DynamoDB Local health check passed
+No existing table 'CRUDLocalTable' found - clean start confirmed
+
+Invoking: sam local invoke CRUDLambdaInitFunction --docker-network host --event /tmp/events/temp_CRUDLambdaInitFunction_event.json
+Raw SAM output: {"statusCode": 200, "body": "CRUDLocalTable"}
+✓ Lambda Init function executed successfully
+
+Invoking: sam local invoke CRUDLambdaCreateFunction --docker-network host --event /tmp/events/temp_CRUDLambdaCreateFunction_event.json  
+Raw SAM output: {"statusCode": 200, "body": "{\"message\": \"Item added\", \"response\": {...}}"}
+✓ Lambda Create function response: {'statusCode': 200, 'message': 'Item added'}
+
+Invoking: sam local invoke CRUDLambdaReadFunction --docker-network host --event /tmp/events/temp_CRUDLambdaReadFunction_event.json
+Raw SAM output: {"statusCode": 200, "body": "{\"name\": \"Batman\", \"Id\": \"123\"}"}
+✓ Lambda Read function response: {'statusCode': 200, 'Item': {'Id': '123', 'name': 'Batman'}}
+
+Invoking: sam local invoke CRUDLambdaUpdateFunction --docker-network host --event /tmp/events/temp_CRUDLambdaUpdateFunction_event.json
+Raw SAM output: {"statusCode": 200, "body": "{\"message\": \"Item updated successfully\", \"response\": {...}}"}
+✓ Lambda Update function response: {'statusCode': 200, 'message': 'Item updated successfully'}
+
+Invoking: sam local invoke CRUDLambdaDeleteFunction --docker-network host --event /tmp/events/temp_CRUDLambdaDeleteFunction_event.json
+Raw SAM output: {"statusCode": 200, "body": "{\"message\": \"Item deleted\", \"response\": {...}}"}
+✓ Lambda Delete function response: {'statusCode': 200, 'message': 'Item deleted'}
+
+✓ Full CRUD workflow completed successfully through Lambda functions
+✓ Performance test completed: avg_lambda_time=1850ms, crud_operations=4
+
+=================== 7 passed in 42.15s ===================
+```
+
+## 🛠️ Troubleshooting
+
+### **Si DynamoDB no está disponible:**
+```
+SKIPPED [1] DynamoDB Local is not running on port 8000. Please start with 'docker run --rm -d --name dynamodb-local --network host amazon/dynamodb-local'
+```
+**Solución:** Ejecutar el comando Docker mostrado.
+
+### **Si SAM build no está actualizado:**
+```
+Lambda import error: No module named 'app'. Please ensure 'sam build' has been run successfully.
+```
+**Solución:** 
+```bash
+cd tests
+sam build
+```
+
+### **Si hay conflictos de puertos:**
+```bash
+# Verificar qué está usando el puerto 8000
+sudo netstat -tlnp | grep :8000
+
+# Matar procesos si es necesario
+docker stop dynamodb-local
+```
+
+### **Si hay problemas de networking:**
+- Verificar que Docker esté corriendo: `docker version`
+- Verificar que `--network host` esté disponible (Linux/macOS)
+- En Windows, puede necesitar configuración especial
+
+## 🔄 Re-ejecución de Tests
+
+Los tests ahora son **completamente idempotentes**:
+
+```bash
+# Puedes ejecutar múltiples veces sin problemas
+python3 -m pytest -s unit/src/test_lambda_dynamodb_local.py
+python3 -m pytest -s unit/src/test_lambda_dynamodb_local.py  # ✅ Funciona
+python3 -m pytest -s unit/src/test_lambda_dynamodb_local.py  # ✅ Funciona
+```
+
+## 📝 Diferencias vs. Versión Anterior
+
+| Aspecto | Versión Anterior | Nueva Versión |
+|---------|------------------|---------------|
+| **DynamoDB Management** | PyTest maneja container | Container externo |
+| **Networking** | Sin `--docker-network host` | Con `--docker-network host` |
+| **Clean State** | No cleanup automático | Cleanup automático al inicio |
+| **Error Handling** | Muestra todos los errores | Filtra warnings harmless |
+| **Idempotency** | No idempotente | Completamente idempotente |
+| **Output** | Confuso con errores | Limpio y claro |
+
+## 🎯 Validación Manual
+
+Para verificar que PyTest replica exactamente el comportamiento manual:
+
+```bash
+# Test manual (debería funcionar igual que PyTest)
+docker run --rm -d --name dynamodb-local --network host amazon/dynamodb-local
+
+sam local invoke CRUDLambdaInitFunction --docker-network host --event ../events/lambda-init-event.json
+sam local invoke CRUDLambdaCreateFunction --docker-network host --event ../events/lambda-create-event.json
+sam local invoke CRUDLambdaReadFunction --docker-network host --event ../events/lambda-read-event.json
+sam local invoke CRUDLambdaUpdateFunction --docker-network host --event ../events/lambda-update-event.json
+sam local invoke CRUDLambdaDeleteFunction --docker-network host --event ../events/lambda-delete-event.json
+
+# Cleanup
+docker stop dynamodb-local
+```
+
+Ambos (manual y PyTest) deberían dar **exactamente los mismos resultados**.

python-test-samples/dynamodb-crud-lambda-local/events/lambda-create-event.json

@@ -0,0 +1,3 @@
+{
+  "body": "{\"Id\": \"123\", \"name\": \"Batman\"}"
+}

python-test-samples/dynamodb-crud-lambda-local/events/lambda-delete-event.json

@@ -0,0 +1,3 @@
+{
+  "Id": "123"
+}

python-test-samples/dynamodb-crud-lambda-local/events/lambda-init-event.json

@@ -0,0 +1,5 @@
+{
+  "key1": "value1",
+  "key2": "value2",
+  "key3": "value3"
+}

python-test-samples/dynamodb-crud-lambda-local/events/lambda-read-event.json

@@ -0,0 +1,3 @@
+{
+  "Id": "123"
+}

python-test-samples/dynamodb-crud-lambda-local/events/lambda-update-event.json

@@ -0,0 +1,3 @@
+{
+  "body": "{\"Id\": \"123\", \"name\": \"Robin\"}"
+}

python-test-samples/dynamodb-crud-lambda-local/lambda_crud_src/lambda_crud_create_src/app.py

@@ -0,0 +1,23 @@
+import os
+import json
+import boto3
+
+def lambda_handler(event, context):
+    # Checking if running locally
+    if os.environ.get('AWS_SAM_LOCAL'):
+        # Use local DynamoDB endpoint
+        dynamodb = boto3.resource('dynamodb', endpoint_url='http://172.17.0.1:8000')
+    else:
+        # Use the default DynamoDB endpoint (AWS)
+        dynamodb = boto3.resource('dynamodb')
+
+    # Adding an item to DynamoDB
+    item = json.loads(event['body'])
+
+    table = dynamodb.Table(os.environ['DYNAMODB_TABLE'])
+    response = table.put_item(Item=item)
+
+    return {
+        'statusCode': 200,
+        'body': json.dumps({'message': 'Item added', 'response': response})
+    }

python-test-samples/dynamodb-crud-lambda-local/lambda_crud_src/lambda_crud_create_src/requirements.txt

@@ -0,0 +1,2 @@
+boto3==1.35.84
+botocore==1.35.84

python-test-samples/dynamodb-crud-lambda-local/lambda_crud_src/lambda_crud_delete_src/app.py

@@ -0,0 +1,24 @@
+import os
+import json
+import boto3
+
+def lambda_handler(event, context):
+    # Checking if running locally
+    if os.environ.get('AWS_SAM_LOCAL'):
+        # Use local DynamoDB endpoint
+        dynamodb = boto3.resource('dynamodb', endpoint_url='http://172.17.0.1:8000')
+    else:
+        # Use the default DynamoDB endpoint (AWS)
+        dynamodb = boto3.resource('dynamodb')
+
+    # Deleting item on DynamoDB
+    #event = json.loads(event['body'])
+    item_id = event['Id']
+
+    table = dynamodb.Table(os.environ['DYNAMODB_TABLE'])
+    response = table.delete_item(Key={'Id': item_id})
+
+    return {
+        'statusCode': 200,
+        'body': json.dumps({'message': 'Item deleted', 'response': response})
+    }

python-test-samples/dynamodb-crud-lambda-local/lambda_crud_src/lambda_crud_delete_src/requirements.txt

@@ -0,0 +1,2 @@
+boto3==1.35.84
+botocore==1.35.84

python-test-samples/dynamodb-crud-lambda-local/lambda_crud_src/lambda_crud_init_src/app.py

@@ -0,0 +1,48 @@
+import os
+import boto3
+
+def lambda_handler(event, context):
+    # Check if running locally
+    if os.environ.get('AWS_SAM_LOCAL'):
+        # Use local DynamoDB endpoint
+        dynamodb = boto3.resource('dynamodb', endpoint_url='http://172.17.0.1:8000')
+    else:
+        # Use the default DynamoDB endpoint (AWS)
+        dynamodb = boto3.resource('dynamodb')
+
+    # Access your DynamoDB table
+    table_name = dynamodb.Table(os.environ['DYNAMODB_TABLE'])
+
+    # Define the table creation parameters
+    table_creation_params = {
+        'TableName': 'CRUDLocalTable',
+        'KeySchema': [
+            {
+                'AttributeName': 'Id',
+                'KeyType': 'HASH'  # Partition key
+            }
+        ],
+        'AttributeDefinitions': [
+            {
+                'AttributeName': 'Id',
+                'AttributeType': 'S'  # String type
+            }
+        ],
+        'ProvisionedThroughput': {
+            'ReadCapacityUnits': 5,
+            'WriteCapacityUnits': 5
+        }
+    }
+
+    # Create the DynamoDB table
+    table = dynamodb.create_table(**table_creation_params)
+
+    # Wait until the table exists before continuing
+    table.wait_until_exists()
+
+    print("Table created successfully:", table.table_name)
+
+    return {
+        'statusCode': 200,
+        'body': table.table_name
+    }

python-test-samples/dynamodb-crud-lambda-local/lambda_crud_src/lambda_crud_init_src/requirements.txt

@@ -0,0 +1,2 @@
+boto3==1.35.84
+botocore==1.35.84

python-test-samples/dynamodb-crud-lambda-local/lambda_crud_src/lambda_crud_read_src/app.py

@@ -0,0 +1,33 @@
+import os
+import json
+import boto3
+
+def lambda_handler(event, context):
+    # Check if running locally
+    if os.environ.get('AWS_SAM_LOCAL'):
+        # Use local DynamoDB endpoint
+        dynamodb = boto3.resource('dynamodb', endpoint_url='http://172.17.0.1:8000')
+    else:
+        # Use the default DynamoDB endpoint (AWS)
+        dynamodb = boto3.resource('dynamodb')
+
+    # Access your DynamoDB table
+    table = dynamodb.Table(os.environ['DYNAMODB_TABLE'])
+
+    item_id = event['Id']
+    response = table.get_item(Key={'Id': item_id})
+
+    item = response.get('Item', {})
+
+    if item:
+        # Item found, return it
+        return {
+            'statusCode': 200,
+            'body': json.dumps(item)
+        }
+    else:
+        # Item not found, return a 404 status
+        return {
+            'statusCode': 404,
+            'body': json.dumps({'error': 'Item not found', 'message': f'No item with Id {item_id} found'})
+        }

python-test-samples/dynamodb-crud-lambda-local/lambda_crud_src/lambda_crud_read_src/requirements.txt

@@ -0,0 +1,2 @@
+boto3==1.35.84
+botocore==1.35.84