git clone https://github.com/Skarlso/google-oauth-go-sample
cd google-oauth-go-sample
go mod download

In order for the Google Authentication to work, you'll need developer credentials which this application gathers from a file in the root directory called creds.json. The structure of this file should be like this:

{
 "installed": {
 "client_id": "hash.apps.googleusercontent.com",
 "project_id": "random",
 "auth_uri": "https://accounts.google.com/o/oauth2/auth",
 "token_uri": "https://oauth2.googleapis.com/token",
 "auth_provider_x509_cert_url": "https://www.googleapis.com/oauth2/v1/certs",
 "client_secret": "secret",
 "redirect_uris": [
 "http://localhost"
 ]
 }
}

To get these credentials:

1. Go to the Google Cloud Console
2. Create a new project or select an existing one
3. Enable the Google+ API
4. Go to "Credentials" → "Create Credentials" → "OAuth 2.0 Client ID"
5. Choose "Web application" as the application type
6. Add http://127.0.0.1:9090/auth to "Authorized redirect URIs"
7. Download the credentials as creds.json and place it in the project root

Note:: The application uses a FIXED session key for development. In production, set a secure 32-byte session key via environment variable or configuration.

# Build the application
go build .
# Run the server
./google-oauth-go-sample

Then navigate to http://127.0.0.1:9090 in your browser.

The protected area is /battle/field.

welcome error logged-in battle logout