oauthCallback.go

// Example of handling Oauth Callback using Golang.
// this function is serving at this endpoint 
// http://localhost:3005/oauth2/callback

func OAuthCallback(w http.ResponseWriter, r *http.Request) {

 // this is getting the code value
 // from our callback url http://localhost:3005/oauth2/callback?code=<some-code-here>
 code := r.URL.Query().Get("code")
 
// We are exchanging the code for an access_token.
// the Exchange function is simply creating a post request to https://github.com/login/oauth/access_token
// with this follwoing payload:
 
// - code: the code that we got earlier.
// - client_id
// - client_secret

// if we use curl it will look like this:
// curl -X POST https://github.com/login/oauth/access_token \
//   -H "Content-Type: application/json" \
//   -H "Accept: application/json" \
//   -d '{
//   "client_id": "the_app_client_id",
//   "client_secret": "the_app_client_secret",
//   "code": "the_code_you_received",
//   }'
 access_token, err := oauth2.Config.Exchange(r.Context(), code)
 
 if err != nil {
 Logger.Error("failed oauth exchange", "error", err)
 w.WriteHeader(http.StatusInternalServerError)
 return
  }
}

// by www.crashloop.sh