create oauth2 server by gin & go-oauth2

token.go

package controllers

import (
	"fmt"
	"log"
	"os"

	"github.com/project/db"
	model "github.com/project/models"

	"github.com/gin-gonic/gin"
	mysql "gopkg.in/go-oauth2/mysql.v3"
	"gopkg.in/oauth2.v3/manage"
	"gopkg.in/oauth2.v3/models"
	"gopkg.in/oauth2.v3/server"
	"gopkg.in/oauth2.v3/store"

	// mysql
	_ "github.com/go-sql-driver/mysql"
)

// CreateToken get tokens
func CreateToken(c *gin.Context) {
	manager := manage.NewDefaultManager()
	// use mysql token store
	tStore := mysql.NewDefaultStore(
		mysql.NewConfig(os.Getenv("DATABASE_URL")),
	)
	defer tStore.Close()
	manager.MapTokenStorage(tStore)
	clientStore := store.NewClientStore()
	clientID := os.Getenv("CLIENT_ID")
	clientSecret := os.Getenv("CLIENT_SECRET")
	clientStore.Set(clientID, &models.Client{
		ID:     clientID,
		Secret: clientSecret,
		Domain: "http://localhost",
	})
	manager.MapClientStorage(clientStore)

	// Initialize the oauth2 service
	srv := server.NewDefaultServer(manager)
	srv.SetClientInfoHandler(server.ClientFormHandler)
	srv.SetPasswordAuthorizationHandler(func(username string, password string) (userID string, err error) {
		admin := model.Admin{}
		db := db.DBInstance(c)
		if err := db.Where("username = ?", username).First(&admin).Error; err != nil {
			err = fmt.Errorf("user not found")
		}
		if admin.ValidatePassword(password) {
			log.Println(username)
			userID = username
			return
		}
		err = fmt.Errorf("密码不正确")
		return
	})
	//ginserver.InitServer(manager)
	//srv.SetAllowedGrantType(oauth2.PasswordCredentials)
	srv.HandleTokenRequest(c.Writer, c.Request)
}