serverless-agnostic

A Serverless Framework Plugin to build provider agnostic serverless express.js applications. This plugin uses jscodeshift to perform transpilations(source-to-source compilations) in Javascript files, in order to adapt them to work with the different serverless providers. The library serverless-httpis also used for enabling express routing in AWS Lambda specific handler format.

1. Installation

Run npm install in your Serverless project.

npm install --save-dev serverless-agnostic

Add the plugin to your serverless.yml file

plugins:
  - serverless-agnostic

2. Configuration

In order to use serverless-agnostic there should be one main .serverless configuration file for the plugin settings and one yaml file for each provider, in this provider yaml files there should be all Serverless Framework configuration required for that specific provider. The suggested name pattern for these files is .serverless-{{PROVIDER_NAME}}.yml.

Sample folder structure for the project:

.
├── ...
  ├── resources                   # sample files
  │   └── sample.png               
  ├── services                   
  │   └── hello-world.js
  ├── index.js
  ├── .serverless-gcp.yml         # GCP serverless config file
  ├── .serverless-aws.yml         # AWS serverless config file
  └── .serverless                 # main serverless config file

Plugin Setup

The main .serverless file should have the plugin specific variables declared in the custom attributes section, under the serverlessAgnostic object.
Here's an example of a .serverless file:

custom:
  serverlessAgnostic:
    serverFile: index.js
    handlerName: myHandler
    serverName: app
    providers:
      - name: aws
        slsFilePath: serverless.aws.yml
      - name: gcp
        slsFilePath: serverless.gcp.yml

Atributes

Attribute	Description
serverFile	Consists of the name/path of the file that contains your express.js application.
handlerName	The name of the handler you're exporting in the module(It should match the handler name in your provider specific yaml file)
serverName	Consists of the variable name used for the express.js application object(usually is app)
providers.name	Refers to the name of the provider(e.g. aws)
providers.slsFilePath	Refers to the name/path of the file that contains the specific configuration for the provider

3. Commands

Compile

The compile command its very straight foward, it compiles your code into the format accepted by the providers you specified in the providers attribute. The default behavior is to compile for all providers, but if you want to compile for one or more specific providers than you can user the --provider or -p flag. The generated files will be stored inside a file called .serverless-agnostic.

For all providers

serverless compile

For specific providers

serverless compile --provider aws

Agnostic Deploy

The agnostic deploy command executes the Serverless Framework deploy for each provider declared, using the configuration described in the provider specific yaml files. The default behavior is to compile for all providers, but if you want to deploy for one or more specific providers than you can user the --provider or -p flag.

For all providers

serverless agnosticDeploy

For specific providers

serverless agnosticDeploy --provider gcp

4. Providers

Currently, the project only supports Amazon Web Services and Google Cloud Platform.