serverless-step-functions-local

Run AWS step functions offline with Serverless!

This is a plugin for the Serverless Framework. It uses stepfunctions-localhost to emulate step functions with AWS' provided tool for local development.

Requirements

The serverless-offline plugin
The serverless-offline-lambda plugin
The serverless-step-functions plugin
Java Runtime Engine (JRE) version 6.x or newer

Install

npm install serverless-step-functions-local -D

Getting Started

You'll need to add this plugin to your serverless.yml. The plugins section should look something like this when you're done:

plugins:
  ...
  - serverless-step-functions
  - serverless-step-functions-local
  - serverless-offline-lambda
  - serverless-offline
  ...

Then, add a new section to config with accountId and region parameters:

custom:
  stepFunctionsLocal:
    accountId: 101010101010
    region: us-east-1

Although not neccessary, it's strongly recomended to add the folder with the downloaded step function executables to .gitignore. By default, this path is ./.step-functions-local.

The plugin binds to port 8083, this cannot be changed.

It also adds an environment variable for each created state machine that contains the ARN for it. These variables are prefixed by OFFLINE_STEP_FUNCTIONS_ARN_, so the ARN of a state machine named 'WaitMachine', for example could be fetched by reading OFFLINE_STEP_FUNCTIONS_ARN_WaitMachine.

Options

(These go under custom.stepFunctionsLocal.)

accountId (required) your AWS account ID
region (required) your AWS region
lambdaEndpoint (defaults to http://localhost:4000) the endpoint for the lambda service
path (defaults to ./.step-functions-local) the path to store the downloaded step function executables
TaskResourceMapping allows for Resource ARNs to be configured differently for local development

Full Config Example

service: local-step-function

plugins:
  - serverless-step-functions
  - serverless-step-functions-local
  - serverless-offline-lambda
  - serverless-offline

provider:
  name: aws
  runtime: nodejs10.x


custom:
  stepFunctionsLocal:
    accountId: 101010101010
    region: us-east-1
    TaskResourceMapping:
      FirstState: arn:aws:lambda:us-east-1:101010101010:function:hello
      FinalState: arn:aws:lambda:us-east-1:101010101010:function:hello

functions:
  hello:
    handler: handler.hello

stepFunctions:
  stateMachines:
    WaitMachine:
      definition:
        Comment: "An example of the Amazon States Language using wait states"
        StartAt: FirstState
        States:
          FirstState:
            Type: Task
            Resource: Fn::GetAtt: [hello, Arn]
            Next: wait_using_seconds
          wait_using_seconds:
            Type: Wait
            Seconds: 10
            Next: FinalState
          FinalState:
            Type: Task
            Resource: Fn::GetAtt: [hello, Arn]
            End: true

ceecko / serverless-step-functions-local