go-cart-api

GOLang Project that provides a simple Endpoint API (/cart) that works as a checkout service.

It receives a JSON containing a list of products with ID and Quantity;
Returning a JSON that contains the checkout list with Its values;
It uses an Internal Database that is populated using a provided JSON file;
It also has a flag that checks If It's Black Friday day, so It will add a Gift to the final checkout list;
Last but not least, there's an integration with a gRPC provided that can apply a discount percentage in the product list. (The .proto file is inside the project in the discount package).

Sample uses

Given the following Database:

[{
  "id": 1,
  "title": "Ergonomic Wooden Pants",
  "description": "Deleniti beatae.",
  "amount": 15157,
  "is_gift": false
},
{
  "id": 2,
  "title": "Ergonomic Cotton Keyboard",
  "description": "Iste est.",
  "amount": 93811,
  "is_gift": true
}]

/cart: Using the request below:

 {
     "products": [
         {
             "id": 1,
             "quantity": 1
         }
     ]
 }

The Normal response:

{
 "total_amount": 15157,
 "total_amount_with_discount": 15157,
 "total_discount": 0,
 "products": [
     {
         "id": 1,
         "quantity": 1,
         "unit_amount": 15157, 
         "total_amount": 15157,
         "discount": 0, 
         "is_gift": false 
     }
 ]
}

The Black Friday response:

{
 "total_amount": 15157,
 "total_amount_with_discount": 15157,
 "total_discount": 0,
 "products": [
     {
         "id": 1,
         "quantity": 1,
         "unit_amount": 15157, 
         "total_amount": 15157,
         "discount": 0, 
         "is_gift": false 
     },
     {
         "id": 2,
         "quantity": 1,
         "unit_amount": 0, 
         "total_amount": 0,
         "discount": 0, 
         "is_gift": true 
     }
 ]
}

The with Discount(5%) response:

{
 "total_amount": 15157,
 "total_amount_with_discount": 14399,
 "total_discount": 758,
 "products": [
     {
         "id": 1,
         "quantity": 1,
         "unit_amount": 15157, 
         "total_amount": 15157,
         "discount": 758, 
         "is_gift": false 
     }
 ]
}

How to run

This can either be done through the docker-compose, docker image or by cloning the repo.

Pre-requisites

The API uses some environment variables, they are all provided in the .env file in the project repository. But in case you don't want to use the file, you can manually setup them or use their default values.

Default values:

1. APP_PATH=/github.com/ChristianPrzybulinski #Used in Docker-Compose

2. DATABASE_PATH=./database #Used to define the database path for the JSON file

3. LOG_LEVEL=info #Used to define the log level

4. BLACK_FRIDAY= #Used to define the black friday day, empty means no Black Friday

5. API_PORT=8080 #The Port that the API will listen to

6. API_HOST= #The Host the API will listen to

7. DISCOUNT_SERVICE_PORT=50051 #The Port to connect in the Discount gRPC Service

8. DISCOUNT_SERVICE_HOST= #The Host to connect in the Discount gRPC Service

9. DISCOUNT_SERVICE_TIMEOUT=1 #The timeout time in seconds for each Discount request

I highly recommend to use docker-compose and the .env file provided.

Through Docker-Compose:

I suggest to clone the repo, so you can have all files and project. But you only need the docker-compose.yml and the .env provided to start up the service. In case you setted the environment variables manually, you won't need the .env file.

Note: In case you're using the default values for the environment variables, you will need to edit the docker-compose.yml filling up the {APP_PATH} to any path you want, {API_PORT} to 8080 and {DISCOUNT_SERVICE_PORT} to 50051.

Starting the service:

docker-compose pull go-cart-api

docker-compose up go-cart-api

You can also start the Discount Service with the same docker-compose.yml provided.

docker-compose pull discount-service

docker-compose up discount-service

Through Docker:

docker run --env-file=.env christianprzybulinski/go-cart-api

docker run -p 50051:50051 hashorg/hash-mock-discount-service

You can skip the --env-file parameter in case you manually configured the environment variables or want to use their default values.

Through Repo:

Note: You won't have the Discount Service. Unless you start a Docker container with it. More importantly, you will need to have GO installed.

Clone the repo;
Inside the go-cart-api/src folder;
You can provide three arguments to run the application (overwriting env vars);

$1 = hostname:port, hostname, port
Example: localhost:8080

$2 = info, debug, warn, error
Example: debug

$3 = the database path
Example: /database

Run the application:

go run . $1 $2 $3
Example: go run . 8080 debug

Note: $GOPATH might need to be configured.

Sample request:

You can test the API Endpoint with any software that provides you a HTTP POST request to be made.

Note: The endpoint will be available at the $API_HOST:$API_PORT/api/v1/cart. In case you used the .env file or the default settings, It is going to be as the example below.

cURL

I recommend using the sample files provided inside the samples folder.

curl -X POST -d "@samples/1.json" "localhost:8080/api/v1/cart"

Final Note: The database JSON name must be products.json in case you want to use your own database file.

# README