orderpacker

README

OrderPacker Service

What is OrderPacker?

OrderPacker is a Golang based application that calculates the number of packs needed to ship to a customer.

How does OrderPacker work?

Frontend

The OrderPacker service also provides a user-friendly frontend, from which the aforementioned API can be conveniently accessed and tested. You can reach the frontend from your browser at:

http://localhost:8080

The frontend itself is quite minimalistic - it contains an input field for submitting the number of items to be packed, and upon submission, it presents neatly formatted API responses. The responses are conveniently displayed, showing each pack and the corresponding quantity.

API

The application exposes its functionality through an HTTP API and accepts a JSON payload with the following structure:

{
  "items": 501
}

The items field is a positive integer that represents the number of items that need to be packed.

The application responds with a JSON payload with the following structure:

{
  "packs": [
    {
      "pack": 250,
      "quantity": 2
    },
    {
      "pack": 1,
      "quantity": 1
    }
  ]
}

It primarily runs on localhost port 8080 and acts upon POST requests to the api/v1/pack endpoint.

Below is a Curl command snippet demonstrating how to call this endpoint

curl --location --request POST 'localhost:8080/api/v1/pack' \
--header 'Content-Type: application/json' \
--data '{
    "items": 501
}'

Configuration

Application follows the 12-factor app methodology and can be configured using environment variables.

Following environment variables are supported:

Name	Description	Default value
PORT	The port on which the application will listen for incoming requests.	8080
HOST	The host on which the application will listen for incoming requests.	0.0.0.0
LOG_LEVEL	The log level of the application.	info
LOG_FORMAT	The log format of the application.	text
PACK_BOXES	The pack boxes for packing orders. Values should be separated by ,	250,500,1000,2000,5000

Development

Prerequisites

• Go 1.23 or higher
• Docker 27.0 or higher
• Docker Compose 2.31 or higher

Running the application

For development purposes, the application can be run locally using the following command:

make build && make run

To build and run the application in a Docker container, use the following command:

make docker-build && make docker-run

Running tests

To run the tests, use the following command:

make test

To run tests without logs, use the following command:

TEST_DISCARD_LOG=true make test

Linting

To run the linter, use the following command:

make vet

Code formatting

To format the code, use the following command:

make format-code

Vendoring

To vendor the dependencies, use the following command:

make vendor