// For rds_creation/index.js
const rds = require('aws-sdk/clients/rds'),
      sns = require('aws-sdk/clients/sns');

const awsClient = new rds();
const snsClient = new sns();

exports.handler = async (event, context) => {
  const record = JSON.parse(event.Records[0].Sns.Message);

  if (record["Event Source"] != "db-instance")          { return; }
  if (record["Event Message"] != "DB instance created") { return; }

  console.log("Requesting instance information for " + record["Source ID"]);
  var data = await awsClient.describeDBInstances(
    {DBInstanceIdentifier: record["Source ID"]}
  ).promise();

  if (data.DBInstances.length == 0) { return; }

  var instance = data.DBInstances[0];
  var credentials = {
    user:     instance.MasterUsername,
    database: instance.DBName,
    host:     instance.Endpoint.Address,
    port:     instance.Endpoint.Port
  };

  await snsClient.publish({
    Message: JSON.stringify(credentials),
    Subject: "Database Created",
    TopicArn: process.env.SNS_TOPIC_ARN
  }).promise();
};