Basic demo of golang grpc

Based on Pluralsight course Enhancing Application Communication with gRPC
Server and Client parts of application which communicate via grpc
Client side exposes graphql API
Represents employees, with ability to upload files and creating vacation requests

Prerequisites

Go
GRPC
Protocol buffers
MongoDB
For testing file upload use Altair graphql client

Install

clone this repository
cd grpc-go-demo
make cert - certificate for TLS, host should be localhost
make build - build binaries (you can find it in ./cmd/ folder)
make server - run domain-server
make client - run api-client
open http://localhost:8080/ for GraphQL playground or use Altair/Postman/Insomnia

Develop

make gql - regenerate graphql client
make gen - regenerate proto files

Client options

For testing file uploading Altair graphql client is recommended

query employees: get list of all employees

 query {
  employees {
    id
    firstName
    lastName
    badgeNumber
    countryCode
    vacationAccrualRate
    vacationAccrued
    documents
    vacations
  }
}

query employees: get list of all employees

query {
  employee(id: "775bc400-9b23-4b40-b336-d591f842f16b") {
    id
    badgeNumber
    firstName
    lastName
    countryCode
    vacationAccrualRate
    vacationAccrued
    documents
    vacations
  }
}

query attachment(ID): get attachment by ID with bytes in property data

query {
  attachment(id: "e9463e2c-9f8e-11ea-91cf-f01898689eb3") {
    id
    userID
    fileName
    data
    createdAt
  }
}

mutation addEmployee(employee): create employee

 mutation {
  addEmployee(
    employee: {
      badgeNumber: 6062
      firstName: "Druzhochek"
      countryCode: "UA"
      lastName: "Pirazhochek"
      vacationAccrualRate: 0.245
      vacationAccrued: 0
    }
  ) {
    id
    badgeNumber
    firstName
    lastName
    countryCode
    vacationAccrualRate
    vacationAccrued
    documents
    vacations
  }
}

mutation addEmployees(employees): create multiple employee

 mutation {
  addEmployees(
    employees: [
      {
        badgeNumber: 203
        firstName: "Druzhochek"
        lastName: "Pirazhochek"
        countryCode: "LS"
        vacationAccrualRate: 0.245
        vacationAccrued: 0
      }
      {
        badgeNumber: 204
        firstName: "Podruzhka"
        lastName: "Vatrushka"
        countryCode: "AS"
        vacationAccrualRate: 1.5
        vacationAccrued: 2
      }
    ]
  ) {
    savedEmployees {
      id
      badgeNumber
      firstName
      lastName
      vacationAccrualRate
      vacationAccrued
      documents
      vacations
    }
    errors
  }
}

mutation addAttachment(file, userID): create attachment for user

{
  "id": "775bc400-9b23-4b40-b336-d591f842f16b"
}

mutation($image: Upload!, $id: String!) {
addAttachment(userID: $id, file: $image) {
  id
  userID
  fileName
  data
  createdAt
  }
}

mutation updateEmployee(employee): update employee fields

  mutation {
  updateEmployee(
    userID: "775bc400-9b23-4b40-b336-d591f842f16b"
    employee: {
      firstName: "John"
      badgeNumber: 1010
      lastName: "Doe"
      countryCode: "US"
      vacationAccrualRate: 2.356
      vacationAccrued: 2
    }
  ) {
    id
    badgeNumber
    firstName
    lastName
    countryCode
    vacationAccrualRate
    vacationAccrued
    vacations
    documents
  }
}

mutation deleteEmployee(id): delete employee

   mutation {
  deleteEmployee(userID: "41578cef-3e2f-4b3d-8982-19fa0328f8b9") {
    id
    firstName
    lastName
    badgeNumber
  }
}

mutation addVacation(vacation): create vacation request for employee

  mutation {
  addVacation(
    vacation: {
      userID: "775bc400-9b23-4b40-b336-d591f842f16b"
      startDate: 1800187289
      durationHours: 48
    }
  ) {
    id
    userId
    startDate
    durationHours
    approved
    cancelled
  }
}

query vacations: get list of all vacations

query {
  vacations {
    id
    userId
    durationHours
    startDate
    approved
    cancelled
  }
}

TODO

✅ storage with Mongo
❌ storage with Postgres
❌ storage for files with S3
❌ add checks for add, update employee queries checks for badgeNum duplication
❌ add graceful shutdown
❌ logging, better error handling, add wrapping where needed
❌ dockerize
❌ deploy (to Heroku, for example)

Shelex / grpc-go-demo