lambda.rb

What can you do with it?

• Write ruby 2.2 (or other Travelling Ruby version) code that runs on AWS Lambda
• Write ruby code that handles Alexa Skills requests

E.g.

• hello-world

require File.join(File.dirname(__FILE__), 'application.rb')

class HelloWorld < Application
  @@application_class = HelloWorld

  def handler(event)
    @event = JSON.parse(event)
    "Got this event - #{@event.to_json}".to_json
  end
end

• hello-world-alexa

require File.join(File.dirname(__FILE__), 'application.rb')
require File.join(File.dirname(__FILE__), 'alexa', 'alexa_application.rb')

class HelloWorldAlexa < AlexaApplication
  @@application_class = HelloWorldAlexa 
  @@application_id = 'amzn1.echo-sdk-ams.app.[xxx]'

  def on_launch(response)
    response.speak_text('Hello from ruby')
  end

  def on_SomeIntent(response)
    response.speak_text("I got this in myslot #{@request.intent.slots.myslot.value}")
  end

  def on_SomeOtherIntent(response)
    response.play_mp3('http://myhost.com/ding_dong.mp3')
  end

  def on_SomeOtherMoreComplicatedIntent(response)
    response.speak_text("Very nice!")
      .with_card(AlexaResponse.card_options('My App Card Title', 'May App Card Contents'))
      .with_reprompt(AlexaResponse.speech_options('What do you want to do next?'))
  end
end

How to use

1. Setup everything AWS

• Sign up for Amazon AWS
• Get access to Amazon S3
• Get access to Amazon Lambda
• Create an IAM account with access to S3 and Lambda
• Install the aws cli tools
• Set up an AWS profile in ~/.aws/credentials for the account created above

2. Create your project

• $ git clone git@github.com:rcunning/lambda.rb.git
• $ cd lambda.rb
• $ rake create[../new-function]

3. Add your credentials and AWS settings

• Edit ../new-function/lambda.rb.yaml
• Make sure to replace your aws_profile name, aws_bucket, aws_subdir

4. Create your AWS Lambda function in the AWS console

• Make sure to name it to match new-function
• Make sure to choose Node 4.3, at least 512 MB memory, at least 10 seconds timeout
• If creating an Alexa Skill, use the Alexa JS sample when creating it

5. Edit your code

• $ vi ../new-function/app/new-function.rb
• Start with something like the e.g. section above
• For Alexa be sure to create your Alexa app and get its id

6. Test your code

• $ rake test[ping]
• or for Alexa
• $ rake test[alexa/launch]

7. Deploy your code

• $ rake deploy

lambda.rb keeps the last used directory as its working target. See the other options

• $ rake -T

Notes

• started with https://github.com/lorennorman/ruby-on-lambda
• execution time is about 200 ms slower per request than JS or python on AWS Lambda