LCSLITX / gRPC-challenge

A technical challenge that consists of creating an API using GoLang and gRPC.

gRPC-challenge

The Technical Challenge consists of creating an API with Golang using gRPC with stream pipes that exposes an Upvote service endpoints. The API will provide the user an interface to upvote or downvote a known list of the main Cryptocurrencies (Bitcoin, ethereum, litecoin, etc..).

Technical requirements:

• Keep the code in Github

API:

• The API must guarantee the typing of user inputs. If an input is expected as a string, it can only be received as a string.
• The structs used with your mongo model should support Marshal/Unmarshal with bson, json and struct
• The API should contain unit test of methods it uses

Extra:

• Deliver the whole solution running in some free cloud service

Brief information

Object	Technology
Server	Go
Client	Go
API	gRPC
Database	MongoDB
Containers	Docker
Cloud Host	-

Instructions to execute

Requirements

• You should have GO (Golang) installed to run both server and client.

• You could use Docker to execute the server or database (or both) inside a container.

• Additionally, you may use Make to execute commands easily with Makefile.

Clone this repository

# ssh
[e-mail]:LCSLITX/gRPC-challenge.git

Important: LiveCryptoVotes method is available only if running on cloud database.

After that, there are a few ways to execute the project;

Building a Go binary (easiest and faster):

1. Change to its directory and simply execute the command make buildRunServer to build and run it.
2. It'll be available to test it with Insonmnia, Postman or BloomRPC. The application is already connected with a cloud database.
3. For a simpler test, you could execute make buildRunClient, to execute Client. Or you could import Insomnia.json file in your Insomnia or manually add .proto files in any request software with gRPC compatibility and add the address 'localhost:50051'.

Within a container:

1. Change to its directory and execute the command make runDockerServer to build and run it inside a container.
2. It'll be available to test it with Insonmnia, Postman or BloomRPC. The application is already connected with a cloud database.
3. For a simpler test, you could execute make buildRunClient, to execute Client. Or you could import Insomnia.json file in your Insomnia or manually add .proto files in any request software with gRPC compatibility and add the address 'localhost:50051'.

With a set of containers, together with mongo and mongo-express:

1. Change to its directory and execute the command docker-compose up to build inside a container.
2. It'll be available to test it with Insonmnia, Postman or BloomRPC. The application is already connected with a cloud database.
3. For a simpler test, you could execute make buildRunClient, to execute Client. Or you could import Insomnia.json file in your Insomnia or manually add .proto files in any request software with gRPC compatibility and add the address 'localhost:50051'.

Ports

The gRPC server is configured to be available at localhost:50051.

The Mongo server is configured to be available at localhost:27017.

The Mongo-Express is configured to be accessible through the browser at URL localhost:8081.

Requests

Important: To run with local database, you should comment the CLOUD_CONNECTION in .env file or simply add a new variable as this TEST="". And after that, execute docker-compose up command. With that, the server will start connected to a local containered MongoDB database running on port 27017.

You could use command docker container ls to check Up containers.

To create requests and use the application, it is recommended to use Insomnia.

You could also run make buildRunClient, to execute the Client files.

There is an exportation .JSON file in the root of this repository. It could be used to import request collection. It is already configured with .proto file and request URL.

Tests

There are unit tests for almost every method created, with exception for liveCryptoVotes method. To run tests you could use the command make tests in root directory, or go test command, inside gRPC-challenge/src/server/ directory, where the server files are located.

Requirements explanation

As previously stated, the challenge consisted of creating an API with GoLang and gRPC. The main requirements were:

• The API must guarantee the typing of user inputs. If an input is expected as a string, it can only be received as a string.

  It was decided to use a Go package called Validator to assure the inputs type.

• The structs used with your mongo model should support Marshal/Unmarshal with bson, json and struct.

  The structs do support Marshall/Unmarshall with bson and json.

• The API should contain unit test of methods it uses

  Almost all endpoints implemented contain unit tests. Total test coverage is 58% and could be ckecked with make tests command.

In addition to these essential requirements:

• The API must have a read, insert, delete and update interfaces.

  The API implements the CRUD interfaces.

• The API must have a method that stream a live update of the current sum of the votes from a given Cryptocurrency.

  The API implements LiveCryptoVotes, which is responsible to stream every vote related to a specific coin. It is not available if running database on Docker because mongo.Watch(), or $changestream stage is only supported on replica sets. Available if running database on cloud.