Instance	Description
gorm.DB	Compatible with original gorm
Logger	Implementation of gorm wrapped by uber-go/zap logger
AutoCreation	Automatically create DB if missing in PostgreSQL

Installation

go get github.com/rookie-ninja/rk-db/postgres

Quick Start

In the bellow example, we will run PostgreSQL locally and implement API of Create/List/Get/Update/Delete for User model with Gin.

GET /v1/user, List users
GET /v1/user/:id, Get user
PUT /v1/user, Create user
POST /v1/user/:id, Update user
DELETE /v1/user/:id, Delete user

Please refer example at example.

0.Import rk-boot/gin as web framework to use

go get github.com/rookie-ninja/rk-boot/gin

1.Create boot.yaml

boot.yaml

Create web server with Gin framework at port 8080
Create PostgreSQL entry which connects PostgreSQL at localhost:5432

---
gin:
  - name: user-service
    port: 8080
    enabled: true
postgres:
  - name: user-db                     # Required
    enabled: true                     # Required
    locale: "*::*::*::*"              # Required
    addr: "localhost:5432"            # Optional, default: localhost:5432
    user: postgres                    # Optional, default: postgres
    pass: pass                        # Optional, default: pass
    database:
      - name: user                    # Required
        autoCreate: true              # Optional, default: false
#        dryRun: false                # Optional, default: false
#        preferSimpleProtocol: false  # Optional, default: false
#        params: []                   # Optional, default: ["sslmode=disable","TimeZone=Asia/Shanghai"]
#    logger:
#      zapLogger: zap                 # Optional, default: default logger with STDOUT

2.Create main.go

In the main() function, we implement two things.

Add User{} as auto migrate option which will create table in DB automatically if missing.
Register APIs into Gin router.

// Copyright (c) 2021 rookie-ninja
//
// Use of this source code is governed by an Apache-style
// license that can be found in the LICENSE file.
package main

import (
	"context"
	"github.com/gin-gonic/gin"
	"github.com/rookie-ninja/rk-boot"
	"github.com/rookie-ninja/rk-boot/gin"
	"github.com/rookie-ninja/rk-db/postgres"
	"gorm.io/gorm"
	"net/http"
	"strconv"
	"time"
)

var userDb *gorm.DB

func main() {
	boot := rkboot.NewBoot()

	boot.Bootstrap(context.TODO())

	// Auto migrate database and init global userDb variable
	pgEntry := rkpostgres.GetPostgresEntry("user-db")
	userDb = pgEntry.GetDB("user")
	if !userDb.DryRun {
		userDb.AutoMigrate(&User{})
	}

	// Register APIs
	ginEntry := rkbootgin.GetGinEntry("user-service")
	ginEntry.Router.GET("/v1/user", ListUsers)
	ginEntry.Router.GET("/v1/user/:id", GetUser)
	ginEntry.Router.PUT("/v1/user", CreateUser)
	ginEntry.Router.POST("/v1/user/:id", UpdateUser)
	ginEntry.Router.DELETE("/v1/user/:id", DeleteUser)

	boot.WaitForShutdownSig(context.TODO())
}

// *************************************
// *************** Model ***************
// *************************************

type Base struct {
	CreatedAt time.Time      `yaml:"-" json:"-"`
	UpdatedAt time.Time      `yaml:"-" json:"-"`
	DeletedAt gorm.DeletedAt `yaml:"-" json:"-" gorm:"index"`
}

type User struct {
	Base
	Id   int    `yaml:"id" json:"id" gorm:"primaryKey"`
	Name string `yaml:"name" json:"name"`
}

func ListUsers(ctx *gin.Context) {
	userList := make([]*User, 0)
	res := userDb.Find(&userList)

	if res.Error != nil {
		ctx.JSON(http.StatusInternalServerError, res.Error)
		return
	}
	ctx.JSON(http.StatusOK, userList)
}

func GetUser(ctx *gin.Context) {
	uid := ctx.Param("id")
	user := &User{}
	res := userDb.Where("id = ?", uid).Find(user)

	if res.Error != nil {
		ctx.JSON(http.StatusInternalServerError, res.Error)
		return
	}
	ctx.JSON(http.StatusOK, user)
}

func CreateUser(ctx *gin.Context) {
	user := &User{
		Name: ctx.Query("name"),
	}

	res := userDb.Create(user)

	if res.Error != nil {
		ctx.JSON(http.StatusInternalServerError, res.Error)
		return
	}
	ctx.JSON(http.StatusOK, user)
}

func UpdateUser(ctx *gin.Context) {
	uid := ctx.Param("id")
	user := &User{
		Name: ctx.Query("name"),
	}

	res := userDb.Where("id = ?", uid).Updates(user)

	if res.Error != nil {
		ctx.JSON(http.StatusInternalServerError, res.Error)
		return
	}

	if res.RowsAffected < 1 {
		ctx.JSON(http.StatusNotFound, "user not found")
		return
	}

	// get user
	userDb.Where("id = ?", uid).Find(user)

	ctx.JSON(http.StatusOK, user)
}

func DeleteUser(ctx *gin.Context) {
	uid, _ := strconv.Atoi(ctx.Param("id"))
	res := userDb.Delete(&User{
		Id: uid,
	})

	if res.Error != nil {
		ctx.JSON(http.StatusInternalServerError, res.Error)
		return
	}

	if res.RowsAffected < 1 {
		ctx.JSON(http.StatusNotFound, "user not found")
		return
	}

	ctx.String(http.StatusOK, "success")
}

3.Start server

$ go run main.go

2022-01-05T22:06:07.755+0800    INFO    boot/gin_entry.go:913   Bootstrap ginEntry      {"eventId": "5ed1c920-5036-4ba2-9f65-f88856ad2d6d", "entryName": "user-service"}
------------------------------------------------------------------------
endTime=2022-01-05T22:06:07.755617+08:00
startTime=2022-01-05T22:06:07.755521+08:00
elapsedNano=96442
timezone=CST
ids={"eventId":"5ed1c920-5036-4ba2-9f65-f88856ad2d6d"}
app={"appName":"rk","appVersion":"","entryName":"user-service","entryType":"GinEntry"}
env={"arch":"amd64","az":"*","domain":"*","hostname":"lark.local","localIP":"10.8.0.2","os":"darwin","realm":"*","region":"*"}
payloads={"ginPort":8080}
error={}
counters={}
pairs={}
timing={}
remoteAddr=localhost
operation=Bootstrap
resCode=OK
eventStatus=Ended
EOE
2022-01-06T19:10:15.730+0800    INFO    Bootstrap postgres entry        {"entryName": "user-db", "postgresUser": "postgres", "postgresAddr": "localhost:5432"}

4.Validation

4.1 Create user

Create a user with name of rk-dev.

$ curl -X PUT "localhost:8080/v1/user?name=rk-dev"
{"id":2,"name":"rk-dev"}

4.1 Update user

Update user name to rk-dev-updated.

$ curl -X POST "localhost:8080/v1/user/2?name=rk-dev-updated"
{"id":2,"name":"rk-dev-updated"}

4.1 List users

List users.

$ curl -X GET localhost:8080/v1/user
[{"id":2,"name":"rk-dev-updated"}]

4.1 Get user

Get user with id=2.

$ curl -X GET localhost:8080/v1/user/2
{"id":2,"name":"rk-dev-updated"}

4.1 Delete user

$ curl -X DELETE localhost:8080/v1/user/2
success

YAML Options

User can start multiple gorm instances at the same time. Please make sure use different names.

name	Required	description	type	default value
postgres.name	Required	The name of entry	string	PostgreSQL
postgres.enabled	Required	Enable entry or not	bool	false
postgres.locale	Required	See locale description bellow	string	""
postgres.description	Optional	Description of echo entry.	string	""
postgres.user	Optional	PostgreSQL username	string	postgres
postgres.pass	Optional	PostgreSQL password	string	pass
postgres.addr	Optional	PostgreSQL remote address	string	localhost:5432
postgres.database.name	Required	Name of database	string	""
postgres.database.autoCreate	Optional	Create DB if missing	bool	false
postgres.database.dryRun	Optional	Run gorm.DB with dry run mode	bool	false
postgres.database.preferSimpleProtocol	Optional	Disable prepared statement cache	bool	false
postgres.database.params	Optional	Connection params	[]string	["sslmode=disable","TimeZone=Asia/Shanghai"]
postgres.logger.zapLogger	Optional	Reference of zap logger entry name	string	""

Usage of locale

RK use <realm>::<region>::<az>::<domain> to distinguish different environment.
Variable of <locale> could be composed as form of <realm>::<region>::<az>::<domain>
- realm: It could be a company, department and so on, like RK-Corp.
         Environment variable: REALM
         Eg: RK-Corp
         Wildcard: supported

- region: Please see AWS web site: https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/using-regions-availability-zones.html
          Environment variable: REGION
          Eg: us-east
          Wildcard: supported

- az: Availability zone, please see AWS web site for details: https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/using-regions-availability-zones.html
      Environment variable: AZ
      Eg: us-east-1
      Wildcard: supported

- domain: Stands for different environment, like dev, test, prod and so on, users can define it by themselves.
          Environment variable: DOMAIN
          Eg: prod
          Wildcard: supported

How it works?
First, we will split locale with "::" and extract realm, region, az and domain.
Second, get environment variable named as REALM, REGION, AZ and DOMAIN.
Finally, compare every element in locale variable and environment variable.
If variables in locale represented as wildcard(*), we will ignore comparison step.

Example:
# let's assuming we are going to define DB address which is different based on environment.
# Then, user can distinguish DB address based on locale.
# We recommend to include locale with wildcard.
---
DB:
  - name: redis-default
    locale: "*::*::*::*"
    addr: "192.0.0.1:6379"
  - name: redis-in-test
    locale: "*::*::*::test"
    addr: "192.0.0.1:6379"
  - name: redis-in-prod
    locale: "*::*::*::prod"
    addr: "176.0.0.1:6379"