README

@aerisweather/deploy-lambda-function

Helper for deploying code to AWS Lambda.

What does it do

Packages your code into a zip file (excludes devDependencies, to keep it small)
Uploads your code to a lambda function
Loads env vars from S3, and applies them to your new lambda function version
Sets the IAM role of your new lambda function version
Points an alias at your new lambda function version

Install

Install via npm:

npm install --save-dev @aerisweather/deploy-lambda-function

Usage

First, you'll need to setup a param.json config files for each deployment environment. For example:

// params.staging.json
{
  // List of directories to include in `zip` file
  "srcDirs": ["dist/lib", "node_modules"],
  // Name of your lambda function on AWS
  "lambdaFunction": "my-lambda-function",
  // Location of environment variables on S3
  "envFile": "s3://my-bucket/env/staging.env",
  // The alias you want to point at your lambda function
  "lambdaAlias": "staging",
  // The IAM role you want to give your lambda function
  "lambdaRole": "arn:aws:iam::ACCOUNT_ID:role/my-lambda-function-staging",
  // The region associated with your lambda function (optional, defaults to us-east-1)
  "lambdaRegion": "us-east-1"
}

To deploy to that environment, run:

node_modules/.bin/deploy-lambda-function -c ./params.staging.json

Programmatic Usage

You can also use this library programmatically, via a node script:

const deployLambdaFunction = require('@aerisweather/deploy-lambda-function').default;

deployLambdaFunction({
  srcDirs: ['dist/lib', 'node_modules'],
  lambdaFunction: 'my-lambda-function',
  envFile: 's3://my-bucket/env/staging.env',
  lambdaAlias: 'staging',
  lambdaRole: 'arn:aws:iam::ACCOUNT_ID:role/my-lambda-function-staging',
  lambdaRegion: 'us-east-1'
})

Example: BitBucket Pipelines

You can setup BitBucket pipelines to deploy to lambda, using deploy-lambda-function.

For this to work, you'll need to:

Create params.json files for prod, staging, and dev
Add the bitbucket-pipelines.yml file below to your repo

# bitbucket-pipelines.yml

# Run on LambCI's lambda-simulation container,
# to give an environment that's close to the real deal
image: lambci/build-nodejs4.3

clone:
  depth: 1

pipelines:
  # Default build scripts...
  default:
    - step:
        script:
          # Configure npm with your NPM_TOKEN
          # (only required if installing from a private npm registry)
          - touch .npmrc && echo "//registry.npmjs.org/:_authToken=${NPM_TOKEN}" >> .npmrc
          # Build and test your code
          - npm install -g npm
          - npm install
          - npm run build
          - npm run test

  # master/staging/development get deployed to lambda
  branches:
    master:
      - step:
          script:
            # Configure npm with your NPM_TOKEN
            # (only required if installing from a private npm registry)
            - touch .npmrc && echo "//registry.npmjs.org/:_authToken=${NPM_TOKEN}" >> .npmrc
            # Build your code
            - npm install && npm build && npm test
            # Deploy to lambda, using prod config
            - ./node_modules/.bin/deploy-lambda-function -c ./deploy/params.prod.json
    staging:
      - step:
          script:
            # Configure npm with your NPM_TOKEN
            # (only required if installing from a private npm registry)
            - touch .npmrc && echo "//registry.npmjs.org/:_authToken=${NPM_TOKEN}" >> .npmrc
            # Build your code
            - npm install && npm build && npm test
            # Deploy to lambda, using staging config
            - ./node_modules/.bin/deploy-lambda-function -c ./deploy/params.staging.json
    development:
      - step:
          script:
            # Configure npm with your NPM_TOKEN
            # (only required if installing from a private npm registry)
            - touch .npmrc && echo "//registry.npmjs.org/:_authToken=${NPM_TOKEN}" >> .npmrc
            # Build your code
            - npm install && npm build && npm test
            # Deploy to lambda, using dev config
            - ./node_modules/.bin/deploy-lambda-function -c ./deploy/params.dev.json

Create an IAM user for Pipelines, with an IAM policy like so

{
    "Version": "2012-10-17",
    "Statement": [
        {
            "Effect": "Allow",
            "Action": [
                "lambda:PublishVersion",
                "lambda:UpdateAlias",
                "lambda:UpdateFunctionCode",
                "lambda:UpdateFunctionConfiguration"
            ],
            "Resource": [
                "arn:aws:lambda:ACCOUNT_REGION:ACCOUNT_ID:function:NAME_OF_YOUR_LAMBDA_FUNCTION"
            ]
        }
    ]
}

Assign the IAM role to an IAM user
Provide IAM user credentials to Pipelines, via env vars
Provide npm credentials to Pipelines, by copying the token from your local ~/.npmrc to the NPM_TOKEN env var in Pipelines
- (only required if installing from a private npm registry)

Usage no npm install needed!