Lambda Function Store ⚡

This repository uses a GitHub Actions workflow to automate the deployment of AWS Lambda functions.

Features 💥

• Deploys all Lambda functions in functions/<app-name>/<function-name>/-style directories
• Deploys all Lambda layers in layers/<layer-name>/-style directories
• Automatically zips and uploads code to S3
• Creates or updates Lambda functions using configuration from config.json
• Attaches layers to Lambda functions using configuration from config.json
• Publishes a new version after each successful deployment
• Updates the appropriate alias based on the branch name
• Skips unchanged functions by comparing commit diffs

Directory Structure 📁

Each Lambda function and layer should live in its own subdirectory and include a config.json file:

functions/
  <app-name>/
    <function-name>/
      index.js
      config.json
layers/
  <layer-name>/
    index.js
    config.json

Example config.json:

{
  "function_name": "MyFunction",
  "runtime": "nodejs18.x",
  "handler": "index.handler",
  "role": "MyLambdaExecutionRole",
  "layers": [
    {
      "eu-central-1": ["MyLayer:1", "MyLayer:2"],
      "us-east-1": ["MyLayer:3", "MyLayer:4"]
    }
  ]
}

Alias Strategy 👾

The workflow chooses a Lambda alias based on the Git branch:

Branch Pattern	Alias
main	prod
release/*	staging
test/*	test
feature/* or other	dev

Deployment Artifacts 📦

Lambda packages are named with a timestamp and Git commit SHA:

Functions: <app>-<function>-<timestamp>-<sha>.zip

Layers: <layer-name>-<timestamp>-<sha>.zip

These are uploaded to S3 under:

Functions: s3://<bucket>/<app>/<function>/

Layers: s3://<bucket>/<layer>

Reguired variables 🔧

• FUNCTIONS_S3_BUCKET (variable): S3 bucket for Lambda functions
• LAYERS_S3_BUCKET (variable): S3 bucket for Lambda layers
• HASHES_S3_BUCKET (variable): S3 bucket for version/hash tracking
• ACCOUNT_NUMBER (secret): Your AWS account number (keep it secret!)

Authentication & Authorization 🔐

Authentication is handled via GitHub OIDC, and access control is managed through AWS IAM roles.

Lambda Requirements 🛠️

• Ensure each Lambda function and layer has a valid config.json
• IAM role must allow Lambda execution and access to CloudWatch Logs