Basics of ThingFabric and AWS Lambda

etl.js

var aws = require('aws-sdk');
var http = require('http');
var s3 = new aws.S3({apiVersion: '2006-03-01'});

exports.handler = function(event, context) {
   var bucket = event.Records[0].s3.bucket.name;
   var key = event.Records[0].s3.object.key;
   s3.getObject({Bucket:bucket, Key:key},
      function(err,data) {
        if (err) {
           console.log('error getting object ' + key + ' from bucket ' + bucket + 
               '. Make sure they exist and your bucket is in the same region as this function.');
           context.done('error','error getting file'+err);
        }
        else {
           console.log('CONTENT TYPE:',data.ContentType);
           var inbound_payload = JSON.parse(data.Body);
           if(inbound_payload.temperature) {
              inbound_payload.temp = {
                  value: (inbound_payload.temperature - 32) * 5 / 9,
                  units: 'Celsius'
              };

             var content = JSON.stringify(inbound_payload);
             var options = {
                 host: 'q.thingfabric.com',
                 path: '/3/publish?domain=foo&client=bar',
                 method: 'POST',
                 headers: {
                     'Content-Type': 'application/json',
                     'Content-Length': content.length,
                     'Authorization': 'Bearer token'
                 }
             };
             
             var req = http.request(options, null);
             req.write(content);
             req.end();
           }

           context.done(null,'');
        }
      }
   );
};

event.json

{
  "Records": [
    {
      "eventVersion": "2.0",
      "eventSource": "aws:s3",
      "awsRegion": "us-east-1",
      "eventTime": "1970-01-01T00:00:00.000Z",
      "eventName": "ObjectCreated:Put",
      "userIdentity": {
        "principalId": "AIDAJDPLRKLG7UEXAMPLE"
      },
      "requestParameters": {
        "sourceIPAddress": "127.0.0.1"
      },
      "responseElements": {
        "x-amz-request-id": "C3D13FE58DE4C810",
        "x-amz-id-2": "FMyUVURIY8/IgAtTv8xRjskZQpcIZ9KG4V5Wp6S7S/JRWeUWerMUE5JgHvANOjpD"
      },
      "s3": {
        "s3SchemaVersion": "1.0",
        "configurationId": "testConfigRule",
        "bucket": {
          "name": "sourcebucket",
          "ownerIdentity": {
            "principalId": "A3NL1KOZZKExample"
          },
          "arn": "arn:aws:s3:::mybucket"
        },
        "object": {
          "key": "sourcebucket/HappyFace.jpg",
          "size": 1024,
          "eTag": "d41d8cd98f00b204e9800998ecf8427e"
        }
      }
    }
  ]
}

readS3.js

var aws = require('aws-sdk');
var s3 = new aws.S3({apiVersion: '2006-03-01'});

exports.handler = function(event, context) {
   var bucket = event.Records[0].s3.bucket.name;
   var key = event.Records[0].s3.object.key;
   s3.getObject({Bucket:bucket, Key:key},
      function(err,data) {
        if (err) {
           console.log('error getting object ' + key + ' from bucket ' + bucket + 
               '. Make sure they exist and your bucket is in the same region as this function.');
           context.done('error','error getting file'+err);
        }
        else {
           var inbound_payload = JSON.parse(data.Body);
           console.log(inbound_payload);
           context.done(null,'');
        }
      }
   );
};

Please change the error handling code to ensure a useful error message is returned.

From:
if (err) {
console.log('error getting object ' + key + ' from bucket ' + bucket +
'. Make sure they exist and your bucket is in the same region as this function.');
}

To:
if (err) console.log(err, err.stack);

Amazingly this exact error message has spread across 50 GitHub Gists. #copypasta