merchant

README

Merchant

It is a conceptual service to store information related to Merchants.

A Merchant is modeled here as follows:

• ID: string
• Username: string, unique, not null
• Password: string, not null, encrypted before storage
• Name: string, not null
• Active: bool
• MaxQPS: int, greater or equal to zero

There is an in memory implementation of a possible Storage service that can be used to persist Merchants in disk.

The service provides 4 endpoints over gRPC:

• GetMerchant to retrieve all the information for a Merchant given its ID.
• GetQPS to retrieve MaxQPS information for a Merchant given its ID.
• MerchantActive to retrieve Active information for a Merchant given its ID.
• MerchantExists to check if a Username and Password matches any Merchant, if so, its ID is returned.

Testing

Unit test

The initialization will create sample Merchants in the memory storage that can be used for testing. Their details can be found in /data/merchants.json.

Please run the tests as follows:

$ go test -v ./... -coverprofile=coverage.out

and verify the coverage (currently ~96%):

$ go tool cover -func=coverage.out

Manual testing

The service can be exposed through gRPC:

$ go run main.go --ip-version=4 --host=0.0.0.0 --port=50051

In a different terminal, please use the grpcurl tool to verify that the endpoints are working as expected.

GetMerchant

• Existing merchant:

$ grpcurl -plaintext -d '{"id": "e1211351-bb91-441f-9ea0-3b243189dec6"}' "0.0.0.0:50051" merchant.MerchantService/GetMerchant | jq .
{
  "id": "e1211351-bb91-441f-9ea0-3b243189dec6",
  "username": "merchant0",
  "password": "$2a$10$TfTXwd7PA.rUrioJrkPbEutsp8WxvJrFDPfOgtTRwolNN3O7m0zKS",
  "name": "Merchant 0 Ltd.",
  "active": true,
  "maxQps": 100
}

• Non existing merchant

$ grpcurl -plaintext -d '{"id": "00000000-0000-0000-0000-000000000000"}' "0.0.0.0:50051" merchant.MerchantService/GetMerchant | jq .
ERROR:
  Code: Unknown
  Message: id does not match any merchant

GetQPS

• Existing merchant:

$ grpcurl -plaintext -d '{"id": "e1211351-bb91-441f-9ea0-3b243189dec6"}' "0.0.0.0:50051" merchant.MerchantService/GetQPS | jq .
{
  "maxQps": 100
}

• Non existing merchant

$ grpcurl -plaintext -d '{"id": "00000000-0000-0000-0000-000000000000"}' "0.0.0.0:50051" merchant.MerchantService/GetQPS | jq .
ERROR:
  Code: Unknown
  Message: id does not match any merchant

MerchantActive

• Existing merchant:

$ grpcurl -plaintext -d '{"id": "e1211351-bb91-441f-9ea0-3b243189dec6"}' "0.0.0.0:50051" merchant.MerchantService/MerchantActive | jq .
{
  "active": true
}

• Non existing merchant

$ grpcurl -plaintext -d '{"id": "00000000-0000-0000-0000-000000000000"}' "0.0.0.0:50051" merchant.MerchantService/MerchantActive | jq .
ERROR:
  Code: Unknown
  Message: id does not match any merchant

FindMerchant

• Correct username and password:

$ grpcurl -plaintext -d '{"username": "merchant0", "password": "password0"}' "0.0.0.0:50051" merchant.MerchantService/FindMerchant | jq .
{
  "exists": true,
  "id": "63e9f8ed-eb67-4448-8448-6b58ec47248d"
}

• Correct username and wrong password:

$ grpcurl -plaintext -d '{"username": "merchant0", "password": "password0000"}' "0.0.0.0:50051" merchant.MerchantService/FindMerchant | jq .
{}

• Invalid username:

$ grpcurl -plaintext -d '{"username": "merchant10", "password": "password0000"}' "0.0.0.0:50051" merchant.MerchantService/FindMerchant | jq .
{}