go-firestore-sample

How to run

Clone the repository

git clone https://github.com/go-tutorials/go-firestore-sample
cd go-firestore-sample

To run the application

go run main.go

Architecture

Simple Layer Architecture

Layer Architecture with full features

core-go/search

API Design

Common HTTP methods

• GET: retrieve a representation of the resource
• POST: create a new resource
• PUT: update the resource
• PATCH: perform a partial update of a resource
• DELETE: delete a resource

API design for health check

To check if the service is available.

Request: GET /health

Response:

{
    "status": "UP",
    "details": {
        "firestore": {
            "status": "UP"
        }
    }
}

API design for users

Resource: users

Get all users

Request: GET /users

Response:

[
    {
        "id": "spiderman",
        "username": "peter.parker",
        "email": "peter.parker@gmail.com",
        "phone": "0987654321",
        "dateOfBirth": "1962-08-25T16:59:59.999Z"
    },
    {
        "id": "wolverine",
        "username": "james.howlett",
        "email": "james.howlett@gmail.com",
        "phone": "0987654321",
        "dateOfBirth": "1974-11-16T16:59:59.999Z"
    }
]

Get one user by id

Request: GET /users/:id

GET /users/wolverine

Response:

{
    "id": "wolverine",
    "username": "james.howlett",
    "email": "james.howlett@gmail.com",
    "phone": "0987654321",
    "dateOfBirth": "1974-11-16T16:59:59.999Z"
}

Create a new user

Request: POST /users

{
    "id": "wolverine",
    "username": "james.howlett",
    "email": "james.howlett@gmail.com",
    "phone": "0987654321",
    "dateOfBirth": "1974-11-16T16:59:59.999Z"
}

Response: 1: success, 0: duplicate key, -1: error

1

Update one user by id

Request: PUT /users/:id

PUT /users/wolverine

{
    "username": "james.howlett",
    "email": "james.howlett@gmail.com",
    "phone": "0987654321",
    "dateOfBirth": "1974-11-16T16:59:59.999Z"
}

Response: 1: success, 0: not found, -1: error

1

Patch one user by id

Perform a partial update of user. For example, if you want to update 2 fields: email and phone, you can send the request body of below.

Request: PATCH /users/:id

PATCH /users/wolverine

{
    "email": "james.howlett@gmail.com",
    "phone": "0987654321"
}

Response: 1: success, 0: not found, -1: error

1

Problems for patch

If we pass a struct as a parameter, we cannot control what fields we need to update. So, we must pass a map as a parameter.

type UserService interface {
	Update(ctx context.Context, user *User) (int64, error)
	Patch(ctx context.Context, user map[string]interface{}) (int64, error)
}

We must solve 2 problems:

1. At http handler layer, we must convert the user struct to map, with json format, and make sure the nested data types are passed correctly.
2. At service layer or repository layer, from json format, we must convert the json format to database format (in this case, we must convert to bson of Mongo)

Solutions for patch

1. At http handler layer, we use core-go/core, to convert the user struct to map, to make sure we just update the fields we need to update

import server "github.com/core-go/core"

func (h *UserHandler) Patch(w http.ResponseWriter, r *http.Request) {
    var user User
    userType := reflect.TypeOf(user)
    _, jsonMap := sv.BuildMapField(userType)
    body, _ := sv.BuildMapAndStruct(r, &user)
    json, er1 := sv.BodyToJson(r, user, body, ids, jsonMap, nil)

    result, er2 := h.service.Patch(r.Context(), json)
    if er2 != nil {
        http.Error(w, er2.Error(), http.StatusInternalServerError)
        return
    }
    respond(w, result)
}

Delete a new user by id

Request: DELETE /users/:id

DELETE /users/wolverine

Response: 1: success, 0: not found, -1: error

1

Common libraries

• core-go/health: include Health Handler, Firestore Health Checker
• core-go/config: to load the config file, and merge with other environments (SIT, UAT, ENV)
• core-go/log: log and log middleware

core-go/health

To check if the service is available, refer to core-go/health

Request: GET /health

Response:

{
    "status": "UP",
    "details": {
        "firestore": {
            "status": "UP"
        }
    }
}

To create health checker, and health handler

	opts := option.WithCredentialsJSON([]byte(root.Credentials))
	app, er1 := firebase.NewApp(ctx, nil, opts)
	if er1 != nil {
		return nil, er1
	}

	client, er2 := app.Firestore(ctx)
	if er2 != nil {
		return nil, er2
	}

	userService := services.NewUserService(client)
	userHandler := handlers.NewUserHandler(userService)

	firestoreChecker := firestore.NewHealthChecker(ctx, []byte(root.Credentials))
	healthHandler := health.NewHealthHandler(firestoreChecker)

To handler routing

	r := mux.NewRouter()
	r.HandleFunc("/health", healthHandler.Check).Methods("GET")

core-go/config

To load the config from "config.yml", in "configs" folder

package app

import (
	"github.com/core-go/log"
	mid "github.com/core-go/log/middleware"
)

type Root struct {
	Server      ServerConfig  `mapstructure:"server"`
	Log         log.Config    `mapstructure:"log"`
	MiddleWare  mid.LogConfig `mapstructure:"middleware"`
	Credentials string        `mapstructure:"credentials"`
}

type ServerConfig struct {
	Name string `mapstructure:"name"`
	Port int64  `mapstructure:"port"`
}

core-go/log & core-go/log/middleware

import (
	"github.com/core-go/config"
	"github.com/core-go/log"
	mid "github.com/core-go/log/middleware"
	"github.com/gorilla/mux"
)

func main() {
	var conf app.Root
	config.Load(&conf, "configs/config")

	r := mux.NewRouter()

	log.Initialize(conf.Log)
	r.Use(mid.BuildContext)
	logger := mid.NewStructuredLogger()
	r.Use(mid.Logger(conf.MiddleWare, log.InfoFields, logger))
	r.Use(mid.Recover(log.ErrorMsg))
}

To configure to ignore the health check, use "skips":

middleware:
  skips: /health