Lab2.md

Lab 2:

Pre-Requisites

IMPORTANT: Make sure you are on the 'EU (Ireland)' AWS Region

The back end hosted as a Lambda function you built in Task 1

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Task 3: Create a DynamoDB for Storing facts

1. In a separate browser tab go to the Amazon Dynamo DB Dashboard
2. Click on 'Create table'
3. In the 'table name' field type ALX402FactDB
4. For 'Partition key' use 'FactId'
   1. Leave the type set to 'String'
5. Leave 'Use Default Settings' checked
6. Click the 'Create' button at the bottom of the page. (This can take a couple of minutes.)
7. On the right hand side click on the 'Indexes' tab
8. Click on the 'Create Index' button
9. Type locale into the 'Primary key' field
   1. Leave the type set to 'String'
   2. The index name should have auto populated to 'locale-index'
10. Don't change any of the other settings
11. Click the 'Create Index' button
    1. This process will take about 5 minutes
    2. The 'Status' will change to 'Active' once it's done
12. Click on the 'Overview' tab
13. Copy the 'Amazon Resource Name (ARN)' for the table, paste it to a text file as we will use it later
    1. It is located at the bottom of the page

Verify: Add an item to the table

14. Click on the 'Items' tab
15. Click the 'Create item' button
16. In the new form that appears, do the following:
    1. Type in 0001 for 'FactId'
    2. Type in en-US for 'locale'
    3. Click the '+' button and append a string.
    4. Type speech for the 'Field' and Manually added fact for the 'Value'
    5. Click the '+' button and append an additional string.
    6. Type text for the 'Field' and Text for manually added fact for the 'Value'
17. Click 'Save' button
18. You now have a properly formatted item stored in DynamoDB

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Task 4: Modify Lambda to read from the new DynamoDB table

1. In a new tab, navigate to the AWS Identity Access Management Service
2. Click on 'Roles' on the left hand side
3. Click on the name 'ALX402-Role'
4. Click 'Attach Policy' button
5. Type DynamoDBReadOnlyAccess in the search bar
6. Click on the checkbox next to 'AmazonDynamoDBReadOnlyAccess'
7. Click 'Attach Policy' button
8. Go back to the Lambda service and select the function called 'ALX402' (We created it in Task 1)
9. Replace the 'GetFact' function with the following code:
   1. The function should start on line

'GetFact': function () {
let requestLocale = this.event.request.locale; //get locale from request for our DB secondary index
let AWS = require('aws-sdk'); //instantiate the aws sdk
let docClient = new AWS.DynamoDB.DocumentClient(); // create a DynamoDB client
let params = { // Parameters object for a query that will return all facts for a locale
  TableName : "ALX402FactDB",
  IndexName: "locale-index",
  KeyConditionExpression: "locale = :v1",
  ExpressionAttributeValues: {
    ":v1": requestLocale
  }
};

let dynamoQuery = docClient.query(params).promise();//create the query and wrap in a promise
dynamoQuery.then(fulfilled.bind(this), rejected.bind(this));//execute query asynchronously

function fulfilled(value) {//function for handling a fulfilled promise
  console.log(value);
  const factArr = value.Items;//array form DynamoDB
  const factIndex = Math.floor(Math.random() * factArr.length); //random int bounded by length of array
  const randomFact = factArr[factIndex]; //get the item that matches the random number
  const speechOutput = randomFact.speech; //get the speech value form the item
  const textOutput = randomFact.text; //get the text value form the item
  this.emit(':tellWithCard', speechOutput, 'ALX 402', textOutput);//send a response to the alexa service
};
function rejected(reason) {//function for handling a rejected promise
  console.log(reason);
  this.emit(':tell', "An Error occurred, please check the console log");
};
},

Verify: Test the code in the lambda console

10. Make sure the 'StartSession' event you created is selected
11. Click on 'Save and Test' on the top right
12. Click the arrow next to 'Details' and review the object being sent back
13. Review the content of the console log

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Lab 3

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Extra Credit:

1. Remove all the hardcoded facts, but leave the other constants