SAM Python Lambda Layers Template

An empty SAM template project integrated with the python project structure allowing seemless local development and remote deployment.

HOW TO USE THIS TEMPLATE

DO NOT FORK Use the template

What is included on this template?

 .
 ├── events                           # Files for simulated events
 │  └── response.json
 ├── hello_world                      # Each Lambda function handler in it's own directory
 │  ├── app.py                        # The function handler itself
 │  └── requirements.txt              # Dependancies of the function hander
 ├── layers
 │  ├── bin                           # Deployed as a separate Layer
 │  │  └── requirements.txt           # All shared libaries go here 
 │  └── project_layer
 │     └── python
 │        └── project_modules         # Built as a pyproject for local development
 │           ├── module.py
 │           └── requirements.txt     # Dependencies of the project_modules
 ├── tests
 │  ├── unit                          # Functional Unit tests
 │  │  └── test_handler.py
 │  └── requirements.txt
 ├── pyproject.toml                   # Install layers as pyproject for local development
 ├── README.md
 ├── requirements.txt                 # Local development dependencies and imports all project dependancies
 └── template.yaml                    # Define your SAM resources

Installation

Create new SAM project by cloning template into a new local project repository.

git clone https://github.com/m6freeman/sam-python-lambda-layer-template my_sam_project
cd my_sam_project; rm -rf .git; git init

---

project_name

project_description

Usage

Establish project virtual environment

python -m venv .venv
. ./.venv/bin/activate
pip install -r requirements.txt

Manage layers pyproject

# pyproject.toml

[tool.setuptools.packages.find]
where = ["layers/project_layer/python/"]
include = ["project_modules"]

[project]
name = "project_modules"

Install layers as a pyproject for local development

pip install -e .

Manage SAM Resources

# template.yaml

HelloWorldFunction:
  Type: AWS::Serverless::Function
  Properties:
    Handler: app.lambda_handler
    CodeUri: hello_world
    Description: Hello World function
    Architectures:
      - x86_64
    Tracing: Active
    Layers:
      - !Ref ProjectLayer
      - !Ref ProjectLibraryLayer

Manage local project dependancies

# requirements.txt

-r layers/project_layer/python/project_modules/requirements.txt
-r layers/bin/requirements.txt
-r hello_world/requirements.txt
aws-sam-cli

Manage deployed project dependancies

# layers/bin/requirements.txt

aws-lambda-powertools
boto3
result
...

Build and Deploy

sam build
sam deploy --guided