feat: add AWS state machine component

[ryankee]

Hey all – I needed AWS step functions so I added in a state machine component. This more or less copies the Function component, but with Pulumi's aws.sfn.StateMachine. I don't love wrapping a definition with an all, so any feedback there would be great.

Here's a quick example of usage:

/// <reference path="./.sst/platform/config.d.ts" />
import { all } from "@pulumi/pulumi";

const myFunction = new sst.aws.Function("MyFunction", {...}); 

const myQueue = new sst.aws.Queue("MyQueue", {...})    

const stateMachine = new sst.aws.StateMachine("MyStateMachine", {
  link: [
    myFunction,
    myQueue,
  ],
  definition: all([
    myFunction.arn,
    myQueue.url,
  ]).apply(
    ([
      myFunctionArn,
      myQueueUrl,
    ]) =>
      JSON.stringify({
        "Comment": "A basic example of a state machine",
        "StartAt": "FirstTask",
        "States": {
          "FirstTask": {
            "Type": "Task",
            "Resource": myFunctionArn,
            "InputPath": "$",
            "Next": "SecondTask",
          },
          "SecondTask": {
            "Type": "Task",
            "Resource": "arn:aws:states:::sqs:sendMessage",
            "InputPath": "$",
            "Parameters": {
              "QueueUrl": myQueueUrl,
              "MessageBody": {
                "Input.$": "$",
              },
              "MessageGroupId.$": "$$.Execution.Id",
            },
            "End": true,
          },
        },
      })
  ),
});

[subvertallchris]

Hey @ryankee, I'm just getting started with Ion and have a need for this, I was happy to see it. How is it working out for you?

[subvertallchris]

I'm happy to report that we are using a copy/paste of this PR's code and it is working wonderfully. We had to add aws.iam.ManagedPolicy.LambdaFullAccess to managedPolicyArns but otherwise no meaningful changes.

I'd love to see this merged. My locally implementation does some nasty things during deploy to work around the lack of .sst prior to first run of sst install.