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Building-Serverless-Python-Apps-Using-AWS-Chalice

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Building-Serverless-Python-Apps-Using-AWS-Chalice #

By the end of this tutorial, you’ll be able to:

  • Discuss the benefits of a serverless architecture
  • Explore Chalice, a Python serverless framework
  • Build a full blown serverless app for a real world use case
  • Deploy to Amazon Web Services (AWS) Lambda
  • Compare Pure and Lambda functions Free Bonus: 5 Thoughts On Python Mastery, a free course for Python developers that shows you the roadmap and the mindset you’ll need to take your Python skills to the next level.

Getting Started With AWS Chalice #

Chalice, a Python Serverless Microframework developed by AWS, enables you to quickly spin up and deploy a working serverless app that scales up and down on its own as required using AWS Lambda. Updating policy for IAM role: hello-world-dev Creating lambda function: hello-world-dev Creating Rest API Resources deployed:

**Note**: The generated ARN and API URL in the above snippet will vary from user to user.
First, let’s include all the import statements:

from os import environ as env

3rd party imports #

from chalice import Chalice, Response from twilio.rest import Client from twilio.base.exceptions import TwilioRestException

Twilio Config #

ACCOUNT_SID = env.get(‘ACCOUNT_SID’) AUTH_TOKEN = env.get(‘AUTH_TOKEN’) FROM_NUMBER = env.get(‘FROM_NUMBER’) TO_NUMBER = env.get(‘TO_NUMBER’)

Next, you’ll encapsulate the Twilio API and use it to send SMS:

app = Chalice(app_name=‘sms-shooter’)

Create a Twilio client using account_sid and auth token #

tw_client = Client(ACCOUNT_SID, AUTH_TOKEN) @app.route(’/service/sms/send’, methods=[‘POST’]) def send_sms(): request_body = app.current_request.json_body if request_body: try: msg = tw_client.messages.create( from_=FROM_NUMBER, body=request_body[‘msg’], to=TO_NUMBER) if msg.sid: return Response(status_code=201, headers={‘Content-Type’: ‘application/json’}, body={‘status’: ‘success’, ‘data’: msg.sid, ‘message’: ‘SMS successfully sent’}) else: return Response(status_code=200, headers={‘Content-Type’: ‘application/json’}, body={‘status’: ‘failure’, ‘message’: ‘Please try again!!!’}) Updating policy for IAM role: sms-shooter-dev Creating lambda function: sms-shooter-dev Creating Rest API Resources deployed:

**Note**: The above command succeeds, and you have your API URL in the output as expected.
Updating policy for IAM role: sms-shooter-dev
Updating lambda function: sms-shooter-dev
Updating rest API
Resources deployed:
- Lambda ARN: arn:aws:lambda:ap-south-1:679337104153:function:sms-shooter-dev
- Rest API URL: https://fqcdyzvytc.execute-api.ap-south-1.amazonaws.com/api/

Do a sanity check by making a curl request to the generated API endpoint:

$ curl -H "Content-Type: application/json" -X POST -d '{"msg": "hey mate!!!"}'
Now to make this work, we need to make changes to `app.py` as well:

Core imports #

from chalice import Chalice, Response from twilio.base.exceptions import TwilioRestException

App level imports #

from chalicelib import sms app = Chalice(app_name=‘sms-shooter’) @app.route(’/’) def index(): return {‘hello’: ‘world’} @app.route(’/service/sms/send’, methods=[‘POST’]) def send_sms(): request_body = app.current_request.json_body if request_body: try: resp = sms.send(request_body) if resp: return Response(status_code=201, headers={‘Content-Type’: ‘application/json’}, body={‘status’: ‘success’, ‘data’: resp.sid, ‘message’: ‘SMS successfully sent’}) else: return Response(status_code=200, headers={‘Content-Type’: ‘application/json’}, body={‘status’: ‘failure’, ‘message’: ‘Please try again!!!’})

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