gin gonic oauth2 integration

oauth2_integration.go

package main

import (
	"bytes"
	"encoding/json"
	"github.com/gin-gonic/gin"
	"golang.org/x/oauth2"
	"golang.org/x/oauth2/bitbucket"
	"golang.org/x/oauth2/github"
	"golang.org/x/oauth2/google"
	"golang.org/x/oauth2/linkedin"
	"io/ioutil"
	"log"
)

var (
	GoogleAuth *oauth2.Config = &oauth2.Config{
		ClientID:     "",
		ClientSecret: "",
		RedirectURL:  "http://localhost:8080/account/google/callback",
		Scopes: []string{
			"https://www.googleapis.com/auth/userinfo.email",
		},
		Endpoint: google.Endpoint,
	}
	GithubAuth *oauth2.Config = &oauth2.Config{
		ClientID:     "",
		ClientSecret: "",
		RedirectURL:  "http://localhost:8080/account/github/callback",
		Scopes: []string{
			"user:email",
		},
		Endpoint: github.Endpoint,
	}
	BitbucketAuth *oauth2.Config = &oauth2.Config{
		ClientID:     "",
		ClientSecret: "",
		RedirectURL:  "http://localhost:8080/account/bitbucket/callback",
		Scopes: []string{
			"email",
		},
		Endpoint: bitbucket.Endpoint,
	}
	LinkedinAuth *oauth2.Config = &oauth2.Config{
		ClientID:     "",
		ClientSecret: "",
		RedirectURL:  "http://localhost:8080/account/linkedin/callback",
		Scopes: []string{
			"r_basicprofile",
			"r_emailaddress",
		},
		Endpoint: linkedin.Endpoint,
	}
)

// google

func gInit(c *gin.Context) {
	url := GoogleAuth.AuthCodeURL("state", oauth2.AccessTypeOffline)
	c.Redirect(302, url)
}

func gCallback(c *gin.Context) {
	code := c.Query("code")
	tok, err := GoogleAuth.Exchange(oauth2.NoContext, code)
	if err != nil {
		log.Fatal(err)
	}
	client := GoogleAuth.Client(oauth2.NoContext, tok)
	resp, err := client.Get("https://www.googleapis.com/plus/v1/people/me")
	if err != nil {
		log.Fatal(err)
	}
	defer resp.Body.Close()
	body, _ := ioutil.ReadAll(resp.Body)
	log.Println("body", string(body))

	var prettyJSON bytes.Buffer
	err = json.Indent(&prettyJSON, body, "", "\t")
	if err != nil {
		log.Println("JSON parse error: ", err)
		return
	}

	c.String(200, string(prettyJSON.Bytes()))
}

// github

func ghInit(c *gin.Context) {
	url := GithubAuth.AuthCodeURL("state", oauth2.AccessTypeOffline)
	c.Redirect(302, url)
}

func ghCallback(c *gin.Context) {
	code := c.Query("code")
	tok, err := GithubAuth.Exchange(oauth2.NoContext, code)
	if err != nil {
		log.Fatal(err)
	}
	client := GithubAuth.Client(oauth2.NoContext, tok)
	resp, err := client.Get("https://api.github.com/user")
	if err != nil {
		log.Fatal(err)
	}
	defer resp.Body.Close()
	body, _ := ioutil.ReadAll(resp.Body)
	log.Println("body", string(body))

	var prettyJSON bytes.Buffer
	err = json.Indent(&prettyJSON, body, "", "\t")
	if err != nil {
		log.Println("JSON parse error: ", err)
		return
	}

	c.String(200, string(prettyJSON.Bytes()))
}

// bitbucket

func bbInit(c *gin.Context) {
	url := BitbucketAuth.AuthCodeURL("state", oauth2.AccessTypeOffline)
	c.Redirect(302, url)
}

func bbCallback(c *gin.Context) {
	code := c.Query("code")
	tok, err := BitbucketAuth.Exchange(oauth2.NoContext, code)
	if err != nil {
		log.Fatal(err)
	}
	client := BitbucketAuth.Client(oauth2.NoContext, tok)
	resp, err := client.Get("https://api.bitbucket.org/2.0/user")
	if err != nil {
		log.Fatal(err)
	}
	defer resp.Body.Close()
	body, _ := ioutil.ReadAll(resp.Body)
	log.Println("body", string(body))

	var prettyJSON bytes.Buffer
	err = json.Indent(&prettyJSON, body, "", "\t")
	if err != nil {
		log.Println("JSON parse error: ", err)
		return
	}

	c.String(200, string(prettyJSON.Bytes()))
}

// linkedin

func lInit(c *gin.Context) {
	url := LinkedinAuth.AuthCodeURL("state", oauth2.AccessTypeOffline)
	c.Redirect(302, url)
}

func lCallback(c *gin.Context) {
	code := c.Query("code")
	tok, err := LinkedinAuth.Exchange(oauth2.NoContext, code)
	if err != nil {
		log.Fatal(err)
	}
	client := LinkedinAuth.Client(oauth2.NoContext, tok)
	resp, err := client.Get("https://api.linkedin.com/v1/people/~:(id,first-name,last-name,email-address)?format=json")
	if err != nil {
		log.Fatal(err)
	}
	defer resp.Body.Close()
	body, _ := ioutil.ReadAll(resp.Body)
	log.Println("body", string(body))

	var prettyJSON bytes.Buffer
	err = json.Indent(&prettyJSON, body, "", "\t")
	if err != nil {
		log.Println("JSON parse error: ", err)
		return
	}

	c.String(200, string(prettyJSON.Bytes()))
}

func home(c *gin.Context) {
	page := `<!DOCTYPE html>
<html>
    <head>
        <meta charset="utf-8">
    </head>
    <body>
        <a href="/link/google">Google+</a>
        <br>
        <a href="/link/github">Github</a>
        <br>
        <a href="/link/bitbucket">Bitbucket</a>
        <br>
        <a href="/link/linkedin">Linkedin</a>
    </body>
</html>
    `
	c.String(200, page)
}

func main() {
	router := gin.New()
	router.Use(gin.Recovery())

	router.GET("/")

	router.GET("/link/google", gInit)
	router.GET("/account/google/callback", gCallback)

	router.GET("/link/github", ghInit)
	router.GET("/account/github/callback", ghCallback)

	router.GET("/link/bitbucket", bbInit)
	router.GET("/account/bitbucket/callback", bbCallback)

	router.GET("/link/linkedin", lInit)
	router.GET("/account/linkedin/callback", lCallback)

	router.Run(":8080")
}