Shopify Backend Developer Intern Challenge: An inventory tracking service for a logistic company.

The following section requires the docker compose and docker engine. Both are included with docker destop install for Windows and MacOS. It is available to download here. On Linux, they are installed seperately. First the engine here, then docker compose here.

1. Run the following command and the API and a database container will start up.

docker-compose up 

When you see the following message the database is ready.

postgres     | 2022-01-15 23:03:23.547 UTC [1] LOG:  database system is ready to accept connections

When you see the following message the API is ready to accept requests.

webserver_1  |  * Serving Flask app 'api' (lazy loading)
webserver_1  |  * Environment: docker
webserver_1  |  * Debug mode: on
webserver_1  |  * Running on all addresses.
webserver_1  |    WARNING: This is a development server. Do not use it in a production deployment.
webserver_1  |  * Running on http://192.168.48.2:8080/ (Press CTRL+C to quit)
webserver_1  |  * Restarting with stat
webserver_1  |  * Debugger is active!
webserver_1  |  * Debugger PIN: 716-097-762

Note: The ports that need to be free are the following: 5432, 8080 and 5050 for the database, flask api and swagger ui respectively.

You can either use the provided swagger-ui one your browser. Or if you prefer to do calls directly to the API continue to the curl section.

Visit swagger-ui on your browser.

1. You'll be greeted with the following page. Here you have an overview of all the endpoints.
2. Let's click on POST /product endpoint. You'll have more detail on the endpoint and you'll be able to call this endpoint with custom payload.
3. Click on Try it out on the top right. You can now change these fields in the payload and execute the call.
4. The response will be displayed with more information.
5. That's the gist of how to use the swagger-ui. Have a play around!

NB: for the following section you may use postman, curl or your favourite HTTP client to make the API calls.

1. First let's try to get a product with id 1:

curl --request GET -i -o - 'http://localhost:8080/inventory/product/1'

We get a 404 status code which is normal because the database is empty.

HTTP/1.0 404 NOT FOUND
Content-Type: application/json
Content-Length: 65
Access-Control-Allow-Origin: *
Server: Werkzeug/2.0.2 Python/3.7.2
Date: Sun, 16 Jan 2022 00:02:54 GMT

{
  "message": "No product found with id: 1", 
  "payload": {}
}

2. Let's create a product:

curl --request POST -i -o - 'http://localhost:8080/inventory/product' \
--header 'Content-Type: application/json' \
--data-raw '{"name": "Lay'\''s Original", "price": 0.99, "weight": 0.001, "description": "Nice crips bag of salty air!"}'

You'll receive the following back. The payload is describes the row that was added to the database. Notice, that the quantity field that is set to 0. This is one of 2 optional attributes, the other being description.

HTTP/1.0 201 CREATED
Content-Type: application/json
Content-Length: 211
Access-Control-Allow-Origin: *
Server: Werkzeug/2.0.2 Python/3.7.2
Date: Sun, 16 Jan 2022 00:39:43 GMT

{
  "message": "CREATE-OK", 
  "payload": {
    "description": "Nice crips bag of salty air!", 
    "id": 1, 
    "name": "Lay's Original", 
    "price": "0.99", 
    "quantity": 0, 
    "weight": "0.001"
  }
}

3. Great! Now we can to to fetch this object from the database.

curl --request GET -i -o - 'http://localhost:8080/inventory/product/1'

We get a 200 status code and the requested resource back under payload!

HTTP/1.0 200 OK
Content-Type: application/json
Content-Length: 204
Access-Control-Allow-Origin: *
Server: Werkzeug/2.0.2 Python/3.7.2
Date: Sun, 16 Jan 2022 00:34:39 GMT

{
  "message": "OK", 
  "payload": {
    "description": "Nice crips bag of salty air!", 
    "id": 1, 
    "name": "Lay's Original", 
    "price": "0.99", 
    "quantity": 0, 
    "weight": "0.001"
  }
}

4. Let's modify the quantity to 55 and the price to 1.99

curl --request PATCH -i -o - 'http://localhost:8080/inventory/product/1' \
--header 'Content-Type: application/json' \
--data-raw '{
    "price": 1.99, 
    "quantity": 1000
  }'

The payload reflects the changes.

HTTP/1.0 200 OK
Content-Type: application/json
Content-Length: 214
Access-Control-Allow-Origin: *
Server: Werkzeug/2.0.2 Python/3.7.2
Date: Sun, 16 Jan 2022 01:04:49 GMT

{
  "message": "UPDATE-OK", 
  "payload": {
    "description": "Nice crips bag of salty air!", 
    "id": 1, 
    "name": "Lay's Original", 
    "price": "1.99", 
    "quantity": 1000, 
    "weight": "0.001"
  }
}

5. Let's add some more product and export a csv!

curl --request POST 'http://localhost:8080/inventory/product' \
--header 'Content-Type: application/json' \
--data-raw '{"description": "Nice crips bag of smokey air!", "name": "Lay'\''s BBQ", "price": 1.99, "quantity": 200, "weight": 0.001}'
curl --request POST 'http://localhost:8080/inventory/product' \
--header 'Content-Type: application/json' \
--data-raw '{"description": "Nice crips bag of tomatoee air!", "name": "Lay'\''s Ketchup", "price": 1.99, "quantity": 100, "weight": 0.001}'
curl --request POST 'http://localhost:8080/inventory/product' \
--header 'Content-Type: application/json' \
--data-raw '{"description": "Nice crips bag of spicy air!", "name": "Lay'\''s Jalapeno", "price": 1.99, "quantity": 100, "weight": 0.001}'

6. Export the csv with the following curl; or just visit the url on a browser!

curl --request GET 'http://localhost:8080/inventory/product/export' 

id,name,price,weight,quantity,description
1,Lay's Original,1.99,0.001,1000,Nice crips bag of salty air!
2,Lay's BBQ,1.99,0.001,200,Nice crips bag of smokey air!
3,Lay's Ketchup,1.99,0.001,100,Nice crips bag of tomatoee air!
4,Lay's Jalapeno,1.99,0.001,100,Nice crips bag of spicy air!