Fix critical appointment service Lambda issues

lambda-petclinic/sample-apps/function2/lambda_function.py

@@ -8,7 +8,17 @@
 table = dynamodb.Table(table_name)
 
 def lambda_handler(event, context):
-    query_params = event.get('queryStringParameters', {})
+    # Add null check for event to prevent errors
+    if event is None:
+        return {
+            'statusCode': 400,
+            'body': json.dumps({'error': 'Invalid request: event is null'}),
+            'headers': {
+                'Content-Type': 'application/json'
+            }
+        }
+
+    query_params = event.get('queryStringParameters') or {}
     current_span = trace.get_current_span()
     # Add an attribute to the current span
     owner_id = random.randint(1, 9)  # Generate a random value between 1 and 9
@@ -18,26 +28,64 @@ def lambda_handler(event, context):
     pet_id = query_params.get('petid')
 
     try:
-        response = table.scan()
+        # Optimize DynamoDB access - use Query instead of Scan for better performance
+        # For demo purposes, we'll use a more efficient approach
+        # If we had a GSI on owners/pet_id, we could query specifically
+        # For now, we'll limit the scan and add pagination
+
+        limit = int(query_params.get('limit', 50))  # Default limit of 50 items
+        last_evaluated_key = query_params.get('lastKey')
+
+        scan_kwargs = {
+            'Limit': limit,
+            'Select': 'ALL_ATTRIBUTES'
+        }
+
+        # Add pagination support
+        if last_evaluated_key:
+            try:
+                scan_kwargs['ExclusiveStartKey'] = json.loads(last_evaluated_key)
+            except (json.JSONDecodeError, TypeError):
+                # Invalid lastKey, ignore and continue without pagination
+                pass
+
+        # Use scan with limit instead of full table scan for better performance
+        response = table.scan(**scan_kwargs)
         items = response.get('Items', [])
 
-        print("Record IDs in DynamoDB Table:")
+        print(f"Retrieved {len(items)} records from DynamoDB Table")
         for item in items:
-            print(item['recordId'])
+            if 'recordId' in item:
+                print(item['recordId'])
 
         record_ids = [record['recordId'] for record in items if 'recordId' in record]
+
+        # Prepare response with pagination info
+        response_body = {
+            'recordIds': record_ids,
+            'count': len(record_ids)
+        }
+
+        # Add pagination info if there are more items
+        if 'LastEvaluatedKey' in response:
+            response_body['lastKey'] = json.dumps(response['LastEvaluatedKey'])
+            response_body['hasMore'] = True
+        else:
+            response_body['hasMore'] = False
 
         return {
             'statusCode': 200,
-            'body': json.dumps({
-                'recordIds': record_ids
-            }),
+            'body': json.dumps(response_body),
             'headers': {
                 'Content-Type': 'application/json'
             }
         }
     except Exception as e:
+        print(f"Error listing records: {str(e)}")
         return {
             'statusCode': 500,
-            'body': json.dumps({'error': str(e)})
-        }
+            'body': json.dumps({'error': 'Internal server error'}),
+            'headers': {
+                'Content-Type': 'application/json'
+            }
+        }

lambda-petclinic/sample-apps/function3/lambda_function.py

@@ -9,19 +9,38 @@
 table = dynamodb.Table(table_name)
 
 def lambda_handler(event, context):
+    # Add null check for event to prevent NullPointerException
+    if event is None:
+        return {
+            'statusCode': 400,
+            'body': json.dumps({'message': 'Invalid request: event is null'}),
+            'headers': {
+                'Content-Type': 'application/json'
+            }
+        }
 
-    query_params = event.get('queryStringParameters', {})
+    # Add null check for queryStringParameters to prevent line 27 error
+    query_params = event.get('queryStringParameters') or {}
+
     current_span = trace.get_current_span()
     # Add an attribute to the current span
     owner_id = random.randint(1, 9)  # Generate a random value between 1 and 9
     current_span.set_attribute("owner.id", owner_id)
 
+    # Add null checks for required parameters
     record_id = query_params.get('recordId')
     owners = query_params.get('owners')
     pet_id = query_params.get('petid')
 
+    # Validate required parameters with proper error handling
     if owners is None or pet_id is None:
-        raise Exception('Missing owner or pet_id')
+        return {
+            'statusCode': 400,
+            'body': json.dumps({'message': 'Missing required parameters: owners and petid are required'}),
+            'headers': {
+                'Content-Type': 'application/json'
+            }
+        }
 
     if record_id is None:
         return {