This web app simulates an inventory management system to manage item records

• Language: Python
• API Framework: FastApi
• Deployment method: AWS Lambda/ AWS API Gateway
• Database: AWS DynamoDB

1. POST {baseUrl}/items. Inserts a new item

   Request body

   {
       "name": "Notebook",
       "category": "Stationary",
       "price": 5.5
   }
   

   Response

   {
       "id": 43640066224263851205823615220508082409
   }
   

2. GET {baseUrl}/items?dt_from=...&dt_to=.... To query for items with last_updated_dt within the datetime range

   Query parameters

   "dt_from": "2022-01-01 10:00:00"
   "dt_to": "2022-01-25 10:00:00"
   

   Response

   {
       "items": [
           {
               "id": 135,
               "name": "Notebook",
               "category": "Stationary",
               "price": 5.5
           },
           {
               "id": 136,
               "name": "Key Chain",
               "category": "Gift",
               "price": 3
           },
           {
               "id": 137,
               "name": "Baggage Cover",
               "category": "Gift",
               "price": 15
           }
       ],
       "total_price": 23.5
   }
   

3. GET {baseUrl}/items/statistics?category=.... Performs aggregation on the data. By passing in a category, the total price and number of items will be returned. If category: “all” is passed, it should return the data for all categories.

   Query parameters

   "category": "all"
   OR
   "category": "Gift"
   

   Response (if "category": "all")

   {
       "items": [
           {
               "category": "Stationary",
               "total_price": 5.5,
               "count": 1
           },
           {
               "category": "Gift",
               "total_price": 18,
               "count": 2
           }
       ]
   }
   

The base url used to test the APIs for each method is shown below.

1. Deploy with docker-compose. Base url is http://localhost:8001

   docker-compose up --build

2. Deploy with AWS SAM. This emulates a deployment with AWS Lambda/AWS API Gateway. Base url is http://localhost:3000

   Build database

   docker-compose up --build dynamodb

   Build docker image to be used by AWS Lambda

   docker build -t my-fastapi-app:latest -f Dockerfile.lambda .

   Start app that uses AWS Lambda/AWS API Gateway and connect it to docker network to access Dynamodb database

   sam local start-api --template aws/template.yaml --docker-network local-network

There are unit tests and integrations tests located in app/tests folder. To run the tests:

docker-compose -f docker-compose-test.yml up --build
docker exec -it fastapi-apigateway-lambda-dynamodb_app-test_1 /bin/bash
pytest