SAH Plugin

A Serverless plugin to create AWS Lambda aliases without imposing a way-of-working with them.

This plugin is based in serverless-simple-alias, we only add support to other events apart from api gateway and specific functionalities to integrate with SAH

Motivation

This plugin assists with two use cases:

1. Creating an "active" alias, and using that alias in API Gateway Event Sources and Event Rules.

Installation

npm install --save-dev sah-plugin

Add the plugin to serverless.yml:

plugins:
  - sah-plugin

Note: Node 10.x or higher runtime required.

Usage

Inside your Serverless config, include this plugin and define a custom.sah object and specify the activeAliasName

plugins:
  - sah-plugin
  ...

custom:
  sah:
    activeAliasName: 'ACTIVE'  # Default: 'ACTIVE'
    useActiveAliasInEvents: true   # Default: false. Whether to change API Gateway to target the active alias or not
    makeLambdasActive: true  # Default: false. Whether to apply the active alias to the lambdas that are being deployed now. Could vary per environment.
    sahUrl: 'http://{app_url}/api/projects/{project_id}/deployments' # Default: null. It is not mandatory but you can use it if you wish to synchronize your displays with your SAH application.
    sahToken: '1|fZH1G7lyRZZKcK4AD8PaaQlXlTeeM7bc2XdjOsqBeecfb75f' # Default: null. It is not mandatory but you can use it if you wish to synchronize your displays with your SAH application.

In practice, different environments have different deployment requirements. For example, in production it may be preferable to not deploy the new versions of the Lambdas with the active tag.

How it works

This plugin changes the following generated AWS CloudFormation templates:

• Adds an AWS::Lambda::Alias resource for each alias, per function, and links each resource to the corresponding AWS::Function::Version resource.
• Changes the existing AWS::ApiGatewayV2::Integration resources (that have Property.IntegrationType of AWS_PROXY) to include the active-alias name in the Property.IntegrationUri
• Changes the existing AWS::Lambda::EventSourceMapping resources to include the active-alias name in the Property.FunctionName
• Changes the existing AWS::Events::Rule resources to include the active-alias name in the Property.Targets
• Changes the existing AWS::Lambda::Permission resources to point the Properties.FunctionName to the AWS::Lambda::Alias resource.