add Twilio functionality

Author: Andrew Stroup

README.md

@@ -92,6 +92,7 @@ Clone this repo and update `lambda_function.py`.
 # lambda_function.py
 account_sid = "account_sid" # Twilio account SID
 auth_token = "auth_token" # Twilio auth token
+phone_number = "phone_number" # Twilio phone number
 dynamodb = boto3.resource('dynamodb', '_region') # AWS region set in Pre-Requisites
 table_users = dynamodb.Table('table_name') # name of DyanmoDB created in Pre-Requisites
 ```

lambda_function.py

@@ -23,6 +23,7 @@
 account_sid = "account_sid"
 auth_token = "auth_token"
 client = TwilioRestClient(account_sid, auth_token)
+phone_number = "phone_number" # +10000000000
 
 # create an S3 & Dynamo session
 s3 = boto3.resource('s3')
@@ -40,6 +41,10 @@ def sample_filter(im):
     filter_image = ImageOps.colorize(ImageOps.grayscale(im), black, white)
     return filter_image
 
+def send_message(event, response):
+    client.messages.create(to=event['fromNumber'], from_=phone_number,
+                                     body=response)
+
 def lambda_handler(event, context):
 
     message = event['body']
@@ -53,11 +58,15 @@ def lambda_handler(event, context):
     # a new user
     if response_dynamo['Count'] == 0:
         if len(message) == 0:
-            return "Please send us an SMS with your name first!"
+            response = "Please send us an SMS with your name first!"
+            send_message(event, response)
+            return response
         else:
             name = message.split(" ")
             table_users.put_item(Item={'fromNumber': from_number, 'name': name[0]})
-            return "We've added {0} to the system! Now send us a selfie! ".format(name[0])
+            response = "We've added {0} to the system! Now send us a selfie! ".format(name[0])
+            send_message(event, response)
+            return response
     else:
         name = response_dynamo['Items'][0]['name']
 
@@ -86,6 +95,8 @@ def lambda_handler(event, context):
 
         s3.Bucket(bucket).put_object(Key=key, Body=im_data, ACL='public-read', ContentType='image/png', Metadata=m_data)
     else:
-        twilio_resp = 'No image found'
-    
+
+        twilio_resp = "No image found, try sending a selfie!"
+
+    send_message(event, twilio_resp)
     return twilio_resp