Gocialite

Gocialite is a Socialite inspired package to manage social oAuth authentication without problems. The idea was born when I discovered that Goth is not so flexible: I was using Revel and it was impossible to connect them properly.

Installation

To install it, just run go get gopkg.in/danilopolani/gocialite.v0 and include it in your app: import "gopkg.in/danilopolani/gocialite.v0".

Available drivers

Amazon
Asana
Bitbucket
Facebook
Foursquare
Github
Google
LinkedIn
Slack

Create new driver

Please see Contributing page to learn how to create new driver and test it.

Set scopes

Note: Gocialite set some default scopes for the user profile, for example for Facebook it specify email and for Google profile, email.
When you use the following method, you don't have to rewrite them.

Use the Scopes([]string) method of your Gocial instance. Example:

gocial.Scopes([]string{"public_repo"})

Set driver

Use the Driver(string) method of your Gocial instance. Example:

gocial.Driver("facebook")

The driver name will be the provider name in lowercase.

How to use it

Note: All Gocialite methods are chainable.

Declare a "global" variable outside your main func:

import (
	...
)

var gocial = gocialite.NewDispatcher()

func main() {

Then create a route to use as redirect bridge, for example /auth/github. With this route, the user will be redirected to the provider oAuth login. In this case we use Gin Tonic as router. You have to specify the provider with the Driver() method. Then, with Scopes(), you can set a list of scopes as slice of strings. It's optional.
Finally, with Redirect() you can obtain the redirect URL. In this method you have to pass three parameters:

Client ID
Client Secret
Redirect URL

func main() {
	router := gin.Default()

	router.GET("/auth/github", redirectHandler)

	router.Run("127.0.0.1:9090")
}

// Redirect to correct oAuth URL
func redirectHandler(c *gin.Context) {
	authURL, err := gocial.New().
		Driver("github"). // Set provider
		Scopes([]string{"public_repo"}). // Set optional scope(s)
		Redirect( // 
			"xxxxxxxxxxxxxx", // Client ID
			"xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx", // Client Secret
			"http://localhost:9090/auth/github/callback", // Redirect URL
		)

	// Check for errors (usually driver not valid)
	if err != nil {
		c.Writer.Write([]byte("Error: " + err.Error()))
		return
	}

	// Redirect with authURL
	c.Redirect(http.StatusFound, authURL) // Redirect with 302 HTTP code
}

Now create a callback handler route, where we'll receive the content from the provider.
In order to validate the oAuth and retrieve the data, you have to invoke the Handle() method with two query parameters: state and code. In your URL, they will look like this: http://localhost:9090/auth/github/callback?state=xxxxxxxx&code=xxxxxxxx.
The Handle() method returns the user info, the token and error if there's one or nil.
If there are no errors, in the user variable you will find the logged in user information and in the token one, the token info (it's a oauth2.Token struct). The data of the user - which is a gocialite.User struct - are the following:

ID
FirstName
LastName
FullName
Email
Avatar (URL)
Raw (the full JSON returned by the provider)

Note that they can be empty.

func main() {
	router := gin.Default()

	router.GET("/auth/github", redirectHandler)
	router.GET("/auth/github/callback", callbackHandler)

	router.Run("127.0.0.1:9090")
}

// Redirect to correct oAuth URL
// Handle callback of provider
func callbackHandler(c *gin.Context) {
	// Retrieve query params for code and state
	code := c.Query("code")
	state := c.Query("state")

	// Handle callback and check for errors
	user, token, err := gocial.Handle(state, code)
	if err != nil {
		c.Writer.Write([]byte("Error: " + err.Error()))
		return
	}

	// Print in terminal user information
	fmt.Printf("%#v", token)
	fmt.Printf("%#v", user)

	// If no errors, show provider name
	c.Writer.Write([]byte("Hi, " + user.FullName))
}

Please take a look to multi provider example for a full working code with Gin Tonic and variable provider handler.

ninhdhx/gocialite