s3.getObject inside lambda doesn't return anything

Question

I have the following code, inside a lambda function, which is an Amazon echo skill:

"AMAZON.HelpIntent": function (intent, session, response) {
  var speechOutput ="Start";

  // Try S3
  var s3 = new AWS.S3({httpOptions: { timeout: 2000 }});
  var params = {
    Bucket: 'bucket',
    Key: 'file',
  };

  s3.getObject(params, function (err, data) {
    if (err) {
      // console.log(err, err.stack);
      speechOutput += "inside error";
      speechOutput += "Did not get it!" + err + ":===:" + err.stack;
    }
    else {
      speechOutput += "inside success";
      // console.log(data);
      speechOutput += "Got it! :" + data.Body.toString('ascii');
    }
  });

  speechOutput += " End. ";

  var repromptText = "Help reprompt.";
  response.ask(speechOutput, repromptText);
},

seems pretty straight forward... however, when the skill is executed, the response is this:

    {
          "version": "1.0",
          "response": {
            "outputSpeech": {
              "type": "PlainText",
              "text": "Start End. "
            },
            "shouldEndSession": false,
            "reprompt": {
              "outputSpeech": {
                "type": "PlainText",
                "text": "Help reprompt."
              }
            }
          },
          "sessionAttributes": {}
   }

In other words, s3.getObject doesn't throw any errors, and doesn't run.

The lamda function has 'lambda_basic_execution' role, which in IAM is defined to have full access to the S3:

{
  "Version": "2012-10-17",
  "Statement": [
    {
      "Effect": "Allow",
      "Action": "s3:*",
      "Resource": "*"
    }
  ]
}

Inside S3, there is a bucket (named 'bucket') and file (named 'file'). File is accessible from CLI, and the web. Permissions on the bucket and file are set to be "everyone".

Please help.

Answer 1

You aren't waiting for the S3 call to complete. The last 3 lines in your code are executing before the s3.getObject() callback has been called. Try changing your code by moving those last 3 lines into the callback, like this:

"AMAZON.HelpIntent": function (intent, session, response) {
  var speechOutput ="Start";

  // Try S3
  var s3 = new AWS.S3({httpOptions: { timeout: 2000 }});
  var params = {
    Bucket: 'bucket',
    Key: 'file',
  };

  s3.getObject(params, function (err, data) {
    if (err) {
      // console.log(err, err.stack);
      speechOutput += "inside error";
      speechOutput += "Did not get it!" + err + ":===:" + err.stack;
    }
    else {
      speechOutput += "inside success";
      // console.log(data);
      speechOutput += "Got it! :" + data.Body.toString('ascii');
    }


    speechOutput += " End. ";

    var repromptText = "Help reprompt.";
    response.ask(speechOutput, repromptText);
  });
},