periodic-ec2-status.js

console.log('Loading function');

var aws = require('aws-sdk');
var region = 'us-west-2';
var ec2 = new aws.EC2({region: region});

var topicArn = "arn:aws:sns:us-west-2:797456418907:cloudius_running_ec2_instances";

function push(payload, context) {
  var sns = new aws.SNS();
  var params = {
    Message: payload, 
    Subject: "EC2 running instancs",
    TopicArn: topicArn
  };
  sns.publish(params,
              function(err, data) {
                if (err) {
                  console.info("error:", err.stack);
                  context.fail(null, err);
                }
                else {
                  console.info('message published to SNS');
                  context.succeed("message published to SNS");
                }
              });
}

function extract_data(data, context) {
  count = data.Reservations.length;
  if (count === 0) {
      context.done(null, "No running instances");
  }
  else {
      var atts = {};
      atts.default = "You have running EC2 instances";
      data.Reservations.map(function(r) {
        r.Instances.map(function(i) {
        id = i.InstanceId;
        atts[id] = {};
        atts[id].PublicIpAddress = i.PublicIpAddress;
        atts[id].keyName = i.KeyName;
        atts[id].LaunchTime = i.LaunchTime;
        atts[id].InstanceType = i.InstanceType;
        console.log(atts[id]);
        });
       });
      push(JSON.stringify(atts,null,'\t'), context);
    }
}

exports.handler = function(event, context) {
  console.log("nLoading handler");
  var msg = JSON.parse(event.Records[0].Sns.Message);
  console.log("msg:", msg);
  if (msg.type != "chime") {
      context.succeed("not a chime event");
      return;
  }
  if (msg.minute != "00") {
      context.succeed("not the top of the hour");
      return;
  }
  ec2.describeInstances( 
    {Filters:
     [{Name: "instance-state-name", Values: ["running"]}]},
    function(err, data) {
      if (err) context.fail(null, err);
      else {
        console.log("successful response from EC2");
        extract_data(data, context);
      }
    }); 
};

// use the following IAM (or more limited)
{
    "Statement": [
        {
            "Action": [
                "logs:CreateLogGroup",
                "logs:CreateLogStream",
                "logs:PutLogEvents"
            ],
            "Effect": "Allow",
            "Resource": "arn:aws:logs:*:*:*"
        },
        {
            "Effect": "Allow",
            "Action": [
                "ec2:*",
                "sns:*"
            ],
            "Resource": "*"
        }
    ]
}