hangouts chat: allow to consume auth data from env var instead of file

[julbrs]

Instead of setting GOOGLE_APPLICATION_CREDENTIALS with the path of the json google auth file, this PR allow to use GOOGLE_APPLICATION_CREDENTIALS_DATA that contains the actual json data. This idea come from here.

It will allow to use botkit as a hangout chat bot on Heroku like systems.

You need to start botkit like that:

$ GOOGLE_APPLICATION_CREDENTIALS_DATA='{
  "type": "service_account",
  "project_id": "your-project-id",
  "private_key_id": "your-private-key-id",
  "private_key": "your-private-key",
  "client_email": "your-client-email",
  "client_id": "your-client-id",
  "auth_uri": "https://accounts.google.com/o/oauth2/auth",
  "token_uri": "https://accounts.google.com/o/oauth2/token",
  "auth_provider_x509_cert_url": "https://www.googleapis.com/oauth2/v1/certs",
  "client_x509_cert_url": "your-cert-url"
}' npm start

See issue #1533

[julbrs]

I have also create a pull request on the dedicated starter project: howdyai/botkit-starter-googlehangouts#1

[ouadie-lahdioui]

Thank you so much for your contribution and for sharing your use case 👍

However, google auth library already offers a smart mechanism to load credentials from environment variables without using .fromJSON() directly on our code to get a JWT, it did that for us inside auth.getClient method.

.getClient() method can create the correct credential type for us, depending upon the environment our code is running under. For example : a JWT auth client will be created when our code is running on ourr local developer machine, and a compute client will be created when the same code is running on Google Cloud Platform.

I propose something like that if you don't mind:

    google_hangouts_botkit.middleware.spawn.use(function(worker, next) {

        let params = {
            scopes: 'https://www.googleapis.com/auth/chat.bot',
            ...configuration.google_auth_params
        };

        google
            .auth
            .getClient(params)
            .then(client => {
                ...
            })
            .catch(err => {
                ...
            });
    });

var controller = Botkit.googlehangoutsbot({
    endpoint: 'Axjn86rTGRQwisaYFyT0XZyiOCh7rZUPGx1A',
    token: "YOUR_TOKEN",
    debug: true,
    google_auth_params: {
        credentials: process.env['CREDS']
    }
});

WDYT ?

[julbrs]

Hello,

will test that ASAP !

[julbrs]

Great it work well ! I have also updated the PR of howdyai/botkit-starter-googlehangouts#1

[ouadie-lahdioui]

LGTM

Thank you @bobman38