Lambda Layers FTW!

Code examples presented at Serverless on stage #16, slides available also here

DISCLAIMER: Automated build/deploy scripts require additional tweaking to be used in a real project (e.g. error checking)

Node.js Demo

Lambda functions (exposed via HTTP) consuming bike-sharing API. Data provider API methods are coded in custom libraries bundled in a shared Lambda Layer.

Contents:

├── bin                     
│   ├── build.sh            # <- build script
│   └── deploy.sh           # <- build script
├── build
│   ├── code-bikemi.zip     # <- lambda function deploy package
│   ├── code-mobike.zip     # <- lambda function deploy package
│   └── layer.zip           # <- layer deploy package
├── src                     
│   ├── bikemi.js           # <- BikeMI data provider (in layer.zip)
│   ├── lambda_bikemi.js    # <- lambda consuming BikeMI API
│   ├── lambda_mobike.js    # <- lambda consuming Mobike API
│   ├── mobike.js           # <- Mobike service API wrapper (in layer.zip)
│   ├── sample-usage.js     # <- sample script
│   └── simple_bikemi.js    # <- lambda example for BikeMI API   
└── template.yml            # <- SAM template

Sample invocaction:

## BikeMI station near Milan Duomo (45.460951,9.188376)
$ curl 'https://slu579if63.execute-api.eu-west-3.amazonaws.com/Prod/bikemi?lat=45.460951&lng=9.188376' | jq .
[
  {
    "bikemi": [
      {
        "lng": 9.1868287,
        "lat": 45.462766,
        "name": "Santa Maria Beltrade",
        "bikes": {
          "standard": 8,
          "electric": 2,
          "babySeat": 0
        },
        "emptySlots": 13,
        "distance": 0.23514495567610313
      },
      {
        "lng": 9.1902244,
        "lat": 45.460017,
        "name": "Velasca",
        "bikes": {
          "standard": 18,
          "electric": 2,
          "babySeat": 0
        },
        "emptySlots": 4,
        "distance": 0.17767506585759438
      },
...

Requirements

• Node.js 8
• aws cli and SAM cli for automated deployment

Up and running

0. Download repo:

git clone git@github.com:flerro/lambda-layers-FTW.git

1. Build and deploy on AWS:

cd lambda-layers-FTW/node-demo
bin/build.sh
bin/deploy.sh

Testing in AWS Console

Sample test events:

• Near Duomo:

  {
      "queryStringParameters": {
          "lat": 45.460951, 
          "lng": 9.188376
      }
  }

• Near Mikamai:

  {
      "queryStringParameters": {
          "lat": 45.4906, 
          "lng": 9.21538
      }
  }

Python Demo

A word cloud generator referencing some python modules from a Lambda Layer. Input text is generated scraping talk titles from Serverless Days 2018 agenda, Ouput image is saved in a S3 bucket.

├── bin                     
│   ├── build.sh       # <- build script
│   ├── deploy.sh      # <- deploy script
│   └── init_venv.sh   # <- virtualenv generation
├── build
│   ├── code.zip       # <- lambda function deploy package
│   └── layer.zip      # <- layer deploy package
├── src                
│   └── wc.py          # <- 
├── venv                
│   └── ...            # <- virtual environment used by build script
└── template.yml       # <- SAM template

Output image:

Requirements

• Python 3.6
• External modules in requirements.txt
• aws cli and SAM cli for automated deployment

Up and running

0. Download repo

git clone git@github.com:flerro/lambda-layers-FTW.git

1. Install requirements in a virtual environment

cd lambda-layers-FTW/python-demo
virtualenv venv
source venv/bin
pip install -r requirements.txt

2. Build and deploy on AWS:

cd python-demo
bin/build.sh
bin/deploy.sh