Backend challenge for Klever

Table of Contents

• Introduction
• Getting Started
• API Endpoints
• Testing

Introduction

Restful API created with Go and the Gin framework that implements some functions of a bitcoin wallet.

Getting Started

Prerequisites:

• Make sure you have Go, version 1.21.4 or higher, installed on your device;
• Create a valid .env file following the .env.example template that is in the root of the project;
• Ensure that no application is listening on port :8080.

Preparing the environment

Before running locally, run the command below to ensure that all dependencies will be installed:

go mod download

Running locally

Running the API without build:

At the root of the project, run the command:

go run ./main.go

Using Makefile commands

The project includes a Makefile to help you manage common tasks more easily. Here's a list of the available commands and a brief description of what they do:

• make run: Run the application in gin debug mode.
• make build: Build the application and create an executable file named gowallet.
• make release: Run the application in gin release mode.
• make test: Run tests for all packages in the project.
• make test-verbose: Run tests for all packages in the project in verbose mode.
• make test-coverage: Runs tests for all packages and shows coverage.
• make clean: Remove the gowallet executable.

To use these commands, simply type make followed by the desired command in your terminal. For example:

make run

Docker and Docker compose

This project includes a Dockerfile and docker-compose.yml file for easy containerization and deployment.

Running application with Docker:

At the root of the project:

• docker build -t your-image-name .: Build a Docker image for the project. Replace your-image-name with a name for your image.
• docker run -d -p 8080:8080 --name your-container-name your-image-name:latest: Run a container based on the built image in detached mode. Replace your-container-name with a name for container and replace your-image-name with the name you used when building the image.
• docker stop your-container-name: Stop the container running the application.
• docker start your-container-name: Restarts the previously initialized container.

Using Docker compose:

If you want to use Docker Compose, follow these commands in the root of the project:

• docker compose up -d: Build and run the services defined in the docker-compose.yml file in detached mode.

To stop and remove containers, networks, and volumes defined in the docker-compose.yml file, run:

docker-compose down

API Endpoints

The base url will be: http://localhost:8080/api/v1

Health [GET]: /health

Try with curl: curl -svX GET 'http://localhost:8080/api/v1/health'

Response:

External API response time is calculated by making three simultaneous calls to the external api using goroutines.

HTTP code: 200 OK

{
  "status": "healthy",
  "timestamp": "2023-12-07T11:58:38-03:00",
  "uptime": "0D 0H 15M 9S",
  "externalApi": {
    "status": "Ok",
    "responseTime": "1169ms"
  }
}

Details [GET]: /details/19SH3YrkrpWXKtCoMXWfoVpmUF1ZHAi24n

Try with curl: curl -svX GET 'http://localhost:8080/api/v1/details/19SH3YrkrpWXKtCoMXWfoVpmUF1ZHAi24n'

Possible responses:

HTTP code: 200 OK

{
  "address": "19SH3YrkrpWXKtCoMXWfoVpmUF1ZHAi24n",
  "balance": "12845845",
  "totalTx": 642,
  "balanceCalc": {
    "confirmed": "12845845",
    "unconfirmed": "0"
  },
  "total": {
    "sent": "176043318",
    "received": "188889163"
  }
}

HTTP code: 404 Not Found

{
    "message": "Adress <invalid_address> not found"
}

HTTP code: 500 Internal Server Error

{
    "message": "Internal server error"
}

HTTP code: 500 Bad Gateway

{
    "message": "Failed to request external resource"
}

Balance [GET]: /balance/19SH3YrkrpWXKtCoMXWfoVpmUF1ZHAi24n

Try with curl: curl -svX GET 'http://localhost:8080/api/v1/balance/19SH3YrkrpWXKtCoMXWfoVpmUF1ZHAi24n'

Possible responses:

HTTP code: 200 OK

{
  "confirmed": "12845845",
  "unconfirmed": "0"
}

HTTP code: 404 Not Found

{
    "message": "Adress <invalid_address> not found"
}

HTTP code: 500 Internal Server Error

{
    "message": "Internal server error"
}

HTTP code: 500 Bad Gateway

{
    "message": "Failed to request external resource"
}

Send [POST]: /send

Request body:

{
  "address": "<string> - Bitcoin address",
  "amount": "<string> - The amount to send (in Satoshis). Note that this should be a string representation of a number"
}

Try with curl: curl -svX POST "http://localhost:8080/api/v1/send" -H 'Content-Type: application/json' -d '{"address": "19SH3YrkrpWXKtCoMXWfoVpmUF1ZHAi24n", "amount": "1208053"}'

Possible responses:

HTTP code: 200 OK

{
  "utxos": [
    {
      "txid": "3672b48dcb1494a30ad94b2cd092cc380d6bb475b86ca547655a65c0c27941e5",
      "amount": "1146600"
    },
    {
      "txid": "4148e2e46000c3a988ae2b7687a40b2bab7f29fb822ecc22912566d7b74330a4",
      "amount": "1100593"
    }
  ]
}

HTTP Code 400 Bad Request

{
    "message": "Error message will depend on the specific issue with the request body"
}

HTTP code: 404 Not Found

{
    "message": "Adress <invalid_address> not found"
}

HTTP code: 500 Internal Server Error

{
    "message": "Internal server error"
}

HTTP code: 500 Bad Gateway

{
    "message": "Failed to request external resource"
}

Transaction [GET]: /tx/3654d26660dcc05d4cfb25a1641a1e61f06dfeb38ee2279bdb049d018f1830ab

Try with curl curl -svX GET 'http://localhost:8080/api/v1/tx/3654d26660dcc05d4cfb25a1641a1e61f06dfeb38ee2279bdb049d018f1830ab'

Possible responses:

HTTP code: 200 OK

{
  "addresses": [
    {
      "address": "bc1qyzxdu4px4jy8gwhcj82zpv7qzhvc0fvumgnh0r",
      "value": "484817655"
    },
    {
      "address": "36iYTpBFVZPbcyUs8pj3BtutZXzN6HPNA6",
      "value": "623579"
    },
    {
      "address": "bc1qyzxdu4px4jy8gwhcj82zpv7qzhvc0fvumgnh0r",
      "value": "422126277"
    }
    ...
  ],
  "block": 675674,
  "txID": "3654d26660dcc05d4cfb25a1641a1e61f06dfeb38ee2279bdb049d018f1830ab"
}

HTTP code: 404 Not Found

{
    "message": "Adress <invalid_transaction_id> not found"
}

HTTP code: 500 Internal Server Error

{
    "message": "Internal server error"
}

HTTP code: 500 Bad Gateway

{
    "message": "Failed to request external resource"
}

Testing

The tests were created with built-in Go packages and the testify toolkit.

To run the tests you can use the makefile commands mentioned above or, at the root of the project, run:

go test ./...

For a more verbose result:

go test -v ./...

To see test coverage:

go test -v ./... -coverprofile=cover.out