Introduction to Serverless Computing for Pythonistas

Piotr Grzesik

What I do ?

What I will be talking about ?

What is serverless computing?
What are the pros and cons of serverless computing?
What are the available platforms and frameworks?
How to create my first serverless Python app?
What is and how to use Serverless framework?

Serverless model

Small, stateless functions that do one thing (FaaS)
Cloud provider is responsible for managing infrastructure
Execution triggered by events
- HTTP Request
- Message from Queue
- Timer
- File upload
Per invocation billing
Integration with other services like DBs, Auth0 (BaaS)

Pros of serverless

No servers to provision and maintain manually
"Infinite" scalability
High availability
Quicker time to market, increased velocity
Smaller total cost of ownership
More focused on delivering business logic

Cons/challenges of serverless

Vendor lock-in
Ephemeral nature of runtime
Cold starts
Increased complexity with growing number of separate functions
Execution duration, limited CPU and RAM
More challenging testing, debugging and monitoring

Example uses for serverless

Multimedia processing (e.g. in response to image upload)
Reacting to database changes (e.g. auditing changes)
IoT sensors message processing (e.g. processing incoming temperature readings)
Stream processing (e.g. processing a stream of messages)
Scheduled or batch jobs (e.g. performing backups)
REST or GraphQL APIs (e.g. web applications)

Serverless is not a silver bullet

Providers/platforms

AWS Lambda
Azure Functions
Google Cloud Functions
Knative
OpenFaaS
IBM OpenWhisk
CloudFlare Workers
Auth0 Webtask
and many more...

AWS Lambda

Serverless computing platform, introduced in 2014 by Amazon Web Services
Out of the box support for Java, .NET Core, Go, Ruby, Python, Node.js. Virtually supports every runtime via custom runtimes introduced in 2018
Easy integration with S3, Kinesis, CloudWatch, API Gateway
Execution time limit - 15 minutes
Up to 3,008 MB of memory per invocation
Support for layers
Lambda@Edge - running code on Edge Locations

Creating our first serverless function!

Available frameworks

Serverless Framework
AWS SAM
Zappa
Chalice

Serverless framework

Written in Node.js
Provider agnostic, supports AWS, Azure, Google Cloud and many more
Supports multiple programming languages
Rich plugin ecosystem
Supports application lifecycle management
Configuration via single yaml file

Serverless framework - useful commands

Installation

Project initialization

Deployment

Function invocation

npm install -g serverless

serverless create --template aws-python3 --path hello-lambda

serverless deploy function -f hello

serverless invoke -f hello

Cleanup

serverless remove

Example serverless.yml

service: example

provider:
  name: aws
  runtime: python3.6
  region: us-east-1
  iamRoleStatements:
    - Effect: "Allow"
      Action:
        - "logs:CreateLogGroup"
        - "logs:CreateLogStream"
        - "logs:PutLogEvents"
      Resource:
        - "arn:aws:logs:*:*:*"
  environment:
    STAGE: ${self:custom.stage}

functions:
  example:
    handler: handler.example
    events:
      - schedule: rate(1 day)

plugins:
  - serverless-python-requirements

custom:
  pythonRequirements:
    dockerizePip: 'non-linux'
  stage: ${opt:stage, self:provider.stage}

Building app with Serverless Framework

Integrates with GitHub
When new PR is created, it checks if PR description contains a Trello card attached
Sends status to GitHub
Sends status information to subscribers (SNS integration)
Saves statuses to DynamoDB
Users can retrieve previous checks

Application diagram

Key points

No servers to manage
Per invocation billing
Scalability and availability
Quicker time to market
Serverless Framework is great

Thanks!

@p_grzesik

pj.grzesik@gmail.com

piotrgrzesik.pl

Introduction to Serverless Computing for Pythonistas

By progressive

Introduction to Serverless Computing for Pythonistas

Introduction to Serverless Computing for Pythonistas

What I do ?

What I will be talking about ?

Serverless model

Pros of serverless

Cons/challenges of serverless

Example uses for serverless

Serverless is not a silver bullet

Providers/platforms

AWS Lambda

Creating our first serverless function!

Available frameworks

Serverless framework

Serverless framework - useful commands

Example serverless.yml

Building app with Serverless Framework

Application diagram

Key points

Recommended readings

Thanks!

Introduction to Serverless Computing for Pythonistas

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