AWS Lambda NodeJS - OAuth to Google API

Question

I'm using my own gmail user to read a public calendar. Got program working locally, and displayed the credentials/token with console.log (value altered to protect my token):

Got Token
OAuth2Client {
  transporter: DefaultTransporter {},
  _certificateCache: null,
  _certificateExpiry: null,
  _clientId: 'xxxxxxxxxxxxxx',
  _clientSecret: 'xxxxxxxxxxxxxxxxxxxxxxxxxxxxxx',
  _redirectUri: 'urn:ietf:wg:oauth:2.0:oob',
  _opts: {},
  credentials:
   { access_token: 'xxxxxxx',
     refresh_token: 'xxxxxxxxxxxxxxxxxx',
     token_type: 'Bearer',
     expiry_date: 1512151860704 } }

I also did what StackOverflow said: How to oAuth Google API from Lambda AWS? and it gave me the same access_token as displayed above.

So, if I understand, I need to take the access token and put it in my program or a file, and I'm not sure how to do that. My code came from the Google example here: https://developers.google.com/google-apps/calendar/quickstart/nodejs

Do I put this token somewhere in my client_secret.json file or what? I tried just passing it straight to the listEvents method as the value of TOKEN but got "400 Bad Request".

Update 1: I tried storing the file to disk and then reading it as follows:

exports.getCalendarJSONEventsNew = 
  function getCalendarJSONEvents(callback) {
    console.log("started getCalendarJSONEventsNew");
    fs.readFile('OAuth2Client.json', 'utf8',
      function processedFile(err, content) {
          if (err) {
            console.log('Error loading OAuth2Client.json: ' + err);
            return;
          }

          console.log("content=");
          console.log(content);
          var tokenFromFile = JSON.parse(content); 
          listEvents(tokenFromFile, function(jsonResult) {
                      console.log("Json Callback Events="); 
                      console.log(jsonResult); 
                      callback(jsonResult); 
          }); 
    }); 

}

Error: It doesn't seem to be exactly be JSON, so not how to deserialize it back into object:

OAuth2Client {
^

SyntaxError: Unexpected token O in JSON at position 0

Update 2: Then I had another idea, I saved the following as

credentials: {
    access_token: 'xxxxx',
    refresh_token: 'xxxxxx',
    token_type: 'Bearer',
    expiry_date: 1512151860704
}

as .credentials/calendar-nodejs-quickstart.json.

Then when I ran on the server, I got this response back:

Authorize this app by visiting this url: https://accounts.google.com/o/oauth2/auth?etc... 

Answer 1

Here's how I got it to work so far.

1) Created a file called calendar-nodejs-quickstart.json in the root directory. I kept getting errors when trying to read .credentials/calendar-nodejs-quickstart.json. I tried setting the environment variables, but ended up changing sample code as follows:

var TOKEN_DIR = '.credentials/';
var TOKEN_PATH = 'calendar-nodejs-quickstart.json';

2) Had to remove "credentials :" from the beginning of the file, and add the double quotes (and also changed single quotes to double quotes). This was to get past various JSON parsing errors. { "access_token": "xxxxx", "refresh_token": "xxxx", "token_type": "Bearer", "expiry_date": 1512151860704 }

3) I also added the 'utf8' below, and added some debug code to see what was going on:

  // Check if we have previously stored a token.
  console.log("TOKEN_PATH=" + TOKEN_PATH); 
  fs.readFile(TOKEN_PATH, 'utf8', function(err, token) {
    if (err) {
      console.log("err=" + err); 
      getNewToken(oauth2Client, callback);
    } else {
      console.log("Use stored tokens from " + TOKEN_PATH); 
      console.log(token); 
      oauth2Client.credentials = JSON.parse(token);
      callback(oauth2Client);
    }
  });

Seems critical to me to show the value of the "err" variable.