go-echo-postgresql-rest-api

a restful api service built with golang + echo framework + elephantSQL (postgresql cloud db)

How to run

Clone the repository

git clone https://github.com/go-tutorials/go-echo-sql-tutorial.git

To run the application

go run main.go

Database

How to create a cloud postgreSQL database with ElephantSQL

• create database document: https://www.elephantsql.com/docs/ (Note: use file data.sql (data -> data.sql) to get the sql query to create new database)
• get URI link for the app to connect: choose the instance database you want to use after created in ElephantSQL, click "Details" option in the left column. Then copy the URL in the "Details" section
• use URI in code: configs -> config.yml. Then paste the URI above to the sql.data_source_name

Echo Framework

get Echo Framework

go get github.com/labstack/echo/v4
go get github.com/labstack/echo/v4/middleware

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": {
        "sql": {
            "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

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 HealthHandler, HealthChecker, SqlHealthChecker
• 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": {
        "sql": {
            "status": "UP"
        }
    }
}

To create health checker, and health handler

    db, err := sql.Open(conf.Driver, conf.DataSourceName)
    if err != nil {
        return nil, err
    }

    sqlChecker := s.NewSqlHealthChecker(db)
    healthHandler := health.NewHealthHandler(sqlChecker)

To handler routing

    e := echo.New()	
    e.GET("/health", app.HealthHandler.Check)

core-go/core/config

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

package main

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

type Root struct {
    DB DatabaseConfig `mapstructure:"db"`
}

type DatabaseConfig struct {
    Driver         string `mapstructure:"driver"`
    DataSourceName string `mapstructure:"data_source_name"`
}

func main() {
    var conf Root
    err := config.Load(&conf, "configs/config")
    if err != nil {
        panic(err)
    }
}

core-go/log & core-go/middleware

import (
	"context"
	"fmt"

	"github.com/core-go/config"
	"github.com/labstack/echo/v4"
	"github.com/labstack/echo/v4/middleware"

	"go-service/internal/app"
)

func main() {
	var conf app.Root

	e := echo.New()

	e.Use(middleware.BodyDump(func(c echo.Context, reqBody, resBody []byte) {
		fmt.Printf("Request Body: %v\n", string(reqBody))
		fmt.Printf("Response Body: %v\n", string(resBody))
		fmt.Printf("----------------------------------------\n")
	}))
	e.Use(middleware.LoggerWithConfig(middleware.LoggerConfig{
		Format: "host=${host}, method=${method}, uri=${uri}, status=${status}, error=${error}, message=${message}\n",
	}))
	e.Use(middleware.Recover())
}

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

middleware:
  skips: /health