问如何从云函数连接Google Cloud SQL？

EN

// Code Sample, of what's working on Localhost.
var functions = require('firebase-functions');

var pg = require('pg');
var pgConfig = {
  user: functions.config().pg.user,
  database: functions.config().pg.database,
  password: functions.config().pg.password,
  host: functions.config().pg.host
}

exports.helloSql = functions.https.onRequest((request, response) => {
  console.log('connecting...');
  try {
    client.connect(function(err) {
      if (err) throw err;

      console.log('connection success');
      console.log('querying...');

      client.query('SELECT * FROM guestbook;', function(err, result){
        if (err) throw err;

        console.log('querying success.');
        console.log('Results: ', result);
        console.log('Ending...');

        client.end(function(err){
          if (err) throw err;
          console.log('End success.');
          response.send(result);
        });
      });

    });
  } catch(er) {
    console.error(er.stack)
    response.status(500).send(er);
  }
});