Every app needs authentication and authorization. Logto is an Auth0 alternative designed for modern apps and SaaS products.
In this article, we will go through the steps to quickly build the GitHub sign-in experience (user authentication) with Go and Logto.
Prerequisites
- A running Logto instance. Check out the introduction page to get started.
- Basic knowledge of Go.
- A usable GitHub account.
Create an application in Logto
In you browser, open a new tab and enter the link of Logto Admin Console.
Once the page is loaded, in the "Get Started" section click the View all link to open the application framework list page.
Choose your application type
In the opening modal, scroll to the "Traditional web" section or filter all the available " Traditional web" frameworks using the quick filter checkboxes on the left.
Click the "undefined" framework card to start creating your application.
Enter application name
Enter the application name, e.g., "Bookstore," and click "Create application."
🎉 Ta-da! You just created your first application in Logto. You'll see a congrats page which includes a detailed integration guide. Follow the guide to see what the experience will be in your application.
Integrate Logto SDK
- The following demonstration is built upon the Gin Web Framework. You may also integrate Logto into other frameworks by taking the same steps.
- The Go sample project is available on our Go SDK repo.
Installation
Execute in the project root directory:
go get github.com/logto-io/go
Add the github.com/logto-io/go/client package to your application code:
// main.go
package main
import (
"github.com/gin-gonic/gin"
// Add dependency
"github.com/logto-io/go/client"
)
func main() {
router := gin.Default()
router.GET("/", func(c *gin.Context) {
c.String(200, "Hello Logto!")
})
router.Run(":3000")
}
Create a session storage
In traditional web applications, the user authentication information will be stored in the user session.
Logto SDK provides a Storage interface, you can implement a Storage adapter based on your web framework so that the Logto SDK can store user authentication information in the session.
We do NOT recommend using cookie-based sessions, as user authentication information stored by Logto may exceed the cookie size limit. In this example, we use memory-based sessions. You can use Redis, MongoDB, and other technologies in production to store sessions as needed.
The Storage type in the Logto SDK is as follows:
package client
type Storage interface {
GetItem(key string) string
SetItem(key, value string)
}
We use github.com/gin-contrib/sessions middleware as an example to demonstrate this process.
Apply the middleware to the application, so that we can get the user session by the user request context in the route handler:
package main
import (
"github.com/gin-contrib/sessions"
"github.com/gin-contrib/sessions/memstore"
"github.com/gin-gonic/gin"
"github.com/logto-io/go/client"
)
func main() {
router := gin.Default()
// We use memory-based session in this example
store := memstore.NewStore([]byte("your session secret"))
router.Use(sessions.Sessions("logto-session", store))
router.GET("/", func(ctx *gin.Context) {
// Get user session
session := sessions.Default(ctx)
// ...
ctx.String(200, "Hello Logto!")
})
router.Run(":3000")
}
Create a session_storage.go file, define a SessionStorage and implement the Logto SDK's Storage interfaces:
package main
import (
"github.com/gin-contrib/sessions"
)
type SessionStorage struct {
session sessions.Session
}
func (storage *SessionStorage) GetItem(key string) string {
value := storage.session.Get(key)
if value == nil {
return ""
}
return value.(string)
}
func (storage *SessionStorage) SetItem(key, value string) {
storage.session.Set(key, value)
storage.session.Save()
}
Now, in the route handler, you can create a session storage for Logto:
session := sessions.Default(ctx)
sessionStorage := &SessionStorage{session: session}
Init LogtoClient
First, create a Logto config:
func main() {
// ...
logtoConfig := &client.LogtoConfig{
Endpoint: "<your-logto-endpoint>", // E.g. http://localhost:3001
AppId: "<your-application-id>",
AppSecret: "<your-application-secret>",
}
// ...
}
You can find and copy "App Secret" from application details page in Admin Console:
Then, you can create a LogtoClient for each user request with the Logto config above:
func main() {
// ...
router.GET("/", func(ctx *gin.Context) {
// Create LogtoClient
session := sessions.Default(ctx)
logtoClient := client.NewLogtoClient(
logtoConfig,
&SessionStorage{session: session},
)
// Use Logto to control the content of the home page
authState := "You are not logged in to this website. :("
if logtoClient.IsAuthenticated() {
authState = "You are logged in to this website! :)"
}
homePage := `<h1>Hello Logto</h1>` +
"<div>" + authState + "</div>"
ctx.Data(http.StatusOK, "text/html; charset=utf-8", []byte(homePage))
})
// ...
}
Implement sign-in route
After the redirect URI is configured, we add a sign-in route to handle the sign-in request and also add an sign-in link on the home page:
func main() {
// ...
// Add a link to perform a sign-in request on the home page
router.GET("/", func(ctx *gin.Context) {
// ...
homePage := `<h1>Hello Logto</h1>` +
"<div>" + authState + "</div>" +
// Add link
`<div><a href="/sign-in">Sign In</a></div>`
ctx.Data(http.StatusOK, "text/html; charset=utf-8", []byte(homePage))
})
// Add a route for handling sign-in requests
router.GET("/sign-in", func(ctx *gin.Context) {
session := sessions.Default(ctx)
logtoClient := client.NewLogtoClient(
logtoConfig,
&SessionStorage{session: session},
)
// The sign-in request is handled by Logto.
// The user will be redirected to the Redirect URI on signed in.
signInUri, err := logtoClient.SignIn("http://localhost:3000/callback")
if err != nil {
ctx.String(http.StatusInternalServerError, err.Error())
return
}
// Redirect the user to the Logto sign-in page.
ctx.Redirect(http.StatusTemporaryRedirect, signInUri)
})
// ...
}
Now, when your user visit http://localhost:3000/sign-in, the user will be redirected to the Logto sign-in page.
Implement the callback route
When the user signs in successfully on the Logto sign-in page, Logto will redirect the user to the Redirect URI.
Since the redirect URI is http://localhost:3000/callback, we add the /callback route to handle the callback after signing in.
func main() {
// ...
// Add a route for handling sign-in callback requests
router.GET("/callback", func(ctx *gin.Context) {
session := sessions.Default(ctx)
logtoClient := client.NewLogtoClient(
logtoConfig,
&SessionStorage{session: session},
)
// The sign-in callback request is handled by Logto
err := logtoClient.HandleSignInCallback(ctx.Request)
if err != nil {
ctx.String(http.StatusInternalServerError, err.Error())
return
}
// Jump to the page specified by the developer.
// This example takes the user back to the home page.
ctx.Redirect(http.StatusTemporaryRedirect, "/")
})
// ...
}
Implement sign-out route
Similar to the sign-in flow, when the user signs out, Logto will redirect the user to the post sign-out redirect URI.
Now, let's add the sign-out route to handle the sign-out request and also add a sign-out link on the home page:
func main() {
// ...
// Add a link to perform a sign-out request on the home page
router.GET("/", func(ctx *gin.Context) {
// ...
homePage := `<h1>Hello Logto</h1>` +
"<div>" + authState + "</div>" +
`<div><a href="/sign-in">Sign In</a></div>` +
// Add link
`<div><a href="/sign-out">Sign Out</a></div>`
ctx.Data(http.StatusOK, "text/html; charset=utf-8", []byte(homePage))
})
// Add a route for handling signing out requests
router.GET("/sign-out", func(ctx *gin.Context) {
session := sessions.Default(ctx)
logtoClient := client.NewLogtoClient(
logtoConfig,
&SessionStorage{session: session},
)
// The sign-out request is handled by Logto.
// The user will be redirected to the Post Sign-out Redirect URI on signed out.
signOutUri, signOutErr := logtoClient.SignOut("http://localhost:3000")
if signOutErr != nil {
ctx.String(http.StatusOK, signOutErr.Error())
return
}
ctx.Redirect(http.StatusTemporaryRedirect, signOutUri)
})
// ...
}
After the user makes a signing-out request, Logto will clear all user authentication information in the session.
Open your Go app to test if the integration works. When you click the "Sign In" button, the page should be redirected to a Logto sign-in page, and you should be able to create a new account by entering username and password and complete the sign-in process.
Add GitHub connector
To add a social connector, go to the "Connector" tab in the Admin Console, then click on "Social connectors". From there, click "Add social connector".
In the openning modal, select "GitHub" and click "Next".
On the next page, you will see a two-column layout with the README content on the left and configuration on the right.
Feel free to follow the README file in place or read the following section to complete the configuration process. If you follow the in-place guide, you can skip the next section.
Set up GitHub OAuth app
Sign in with GitHub account
Go to the GitHub website and sign in with your GitHub account. You may register a new account if you don't have one.
Create and configure OAuth app
Follow the creating an OAuth App guide, and register a new application.
Name your new OAuth application in Application name and fill up Homepage URL of the app.
You can leave Application description field blank and customize Authorization callback URL as ${your_logto_origin}/callback/${connector_id}. The connector_id can be found on the top bar of the Logto Admin Console connector details page.
Note: If you encounter the error message "The redirect_uri MUST match the registered callback URL for this application." when logging in, try aligning the Authorization Callback URL of your GitHub OAuth App and your Logto App's redirect URL (of course, including the protocol) to resolve the issue.
We suggest not to check the box before Enable Device Flow, or users who sign in with GitHub on mobile devices must confirm the initial sign-in action in the GitHub app. Many GitHub users do not install the GitHub mobile app on their phones, which could block the sign-in flow. Please ignore our suggestion if you are expecting end-users to confirm their sign-in flow. See details of device flow.
Managing OAuth apps
Go to the OAuth Apps page and you can add, edit or delete existing OAuth apps.
You can also find Client ID and generate Client secrets in OAuth app detail pages.
Compose the connector JSON
Let's go back to Logto. Fill out the clientId and clientSecret field with Client ID and Client Secret you've got from OAuth app detail pages mentioned in the previous section.
Here is an example of GitHub connector config JSON.
{
"clientID": "<your-client-id>",
"clientSecret": "<your-client-secret>"
}
Config types
| Name | Type |
|---|---|
| clientId | string |
| clientSecret | string |
Save your configuration
Double check you have filled out necessary values in the Logto connector configuration area. Click "Save and Done" (or "Save changes") and the GitHub connector should be available now.
Enable GitHub connector in Sign-in Experience
Switch to the "Sign-in experience" tab, then click the "Sign-up and sign-in" tab.
If it's the first time you enter the tab, you will see a quick introduction about Sign-in Experience and its basic configuration.
Select "None" for the "Sign-up identifier" to provide minimum sign-up effort for GitHub sign-in, which may increase your conversion rate.
In the "Social sign-in" section, add "Add Social Connector" and choose "GitHub". Then you should be able to see a button with text "Continue with GitHub" in the preview section.
Finally, click "Save changes" on the bottom right corner.
Testing and Validation
Return to your Go app. You should now be able to sign in with GitHub. Enjoy!
Further readings
Protect your API For native and single page apps, you'll need to call one or more API endpoints to retrieve and update data.
Learn more about identifying who's who and keeping your API secure.
User management We know you care about user management and activities, as we also do.
Learn more about how to know your users and see the figures like DAU and MAU graphically.
Localization From one regional business to a global corporate, the willingness to offer the best user experience won't change.
You can change current language phrases or add a new language without friction.
Customer IAM series Our serial blog posts about Customer (or Consumer) Identity and Access Management, from 101 to advanced topics and beyond.