google

Google Login

Login with Google allows users to login to any web app with their Google account.

Web

Package gologin provides Go handlers for the Google OAuth2 Authorization flow and for obtaining the Google Userinfoplus struct.

Getting Started

go get github.com/dghubble/gologin/google
cd $GOPATH/src/github.com/dghubble/gologin/examples/google
go get .

Example App

main.go shows an example web app which uses gologin to issue a client-side cookie session. For simplicity, no data is persisted.

Visit Google Developer Console under Project, APIs, Credentials to get your OAuth2 client credentials. Add http://localhost:8080/google/callback as a valid OAuth2 Redirect URL.

Compile and run main.go from examples/google. Pass the client id and secret as arguments to the executable

go run main.go -client-id=xx -client-secret=yy
2015/09/25 23:09:13 Starting Server listening on localhost:8080

or set the GOOGLE_CLIENT_ID and GOOGLE_CLIENT_SECRET environment variables.

Here's what the flow looks like.

Authorization Flow

1. The "Login with Google" link to the login handler directs the user to the Google OAuth2 Auth URL to obtain a permission grant.
2. The redirection URI (callback handler) receives the OAuth2 callback, verifies the state parameter, and obtains a Token.
3. The success http.Handler is called with a Context which contains the Google Token and verified Google Userinfoplus struct.
4. In this example, that User is read and used to issue a signed cookie session.