Beginnings of Callback flow

source/SIL.AppBuilder.Portal.AWS.Step/README.md

@@ -1,11 +1,12 @@
 # Testing AWS Step Functions Locally
 
+1. If you don't already have the AWS Local Step Functions Docker Image, `docker pull amazon/aws-stepfunctions-local`
 1. Create a `.env` file with these contents.
 ```
 AWS_DEFAULT_REGION=dummy
 AWS_ACCESS_KEY_ID=dummy
 AWS_SECRET_ACCESS_KEY=dummy
 ```
-2. `npm i`
-2. `npm start`
-2. Use Postman to interact with the REST API
+3. `npm i`
+3. `npm start`
+3. Use Postman to interact with the REST API

source/SIL.AppBuilder.Portal.AWS.Step/api.js

@@ -1,8 +1,15 @@
 const express = require('express');
 const bodyParser = require('body-parser');
 const cors = require('cors');
+const fs = require('node:fs');
 
-const { SFNClient, ListStateMachinesCommand } = require("@aws-sdk/client-sfn"); // CommonJS import
+const { 
+  SFNClient, 
+  CreateStateMachineCommand,
+  DescribeStateMachineCommand,
+  ListStateMachinesCommand,
+  StartExecutionCommand
+} = require("@aws-sdk/client-sfn"); // CommonJS import
 
 const client = new SFNClient({
   endpoint: `http://localhost:8083`,
@@ -13,6 +20,8 @@ const client = new SFNClient({
   }
 });
 
+const machines = {};
+
 const app = express();
 
 const port = 3000;
@@ -31,15 +40,66 @@ app.post('/echo', (req, res) => {
   console.log(req.body);
 });
 
-app.get('/machines', async (req, res) => {
+async function listMachines() {
   try {
-    const response = await client.send(new ListStateMachinesCommand());
-    res.send(response);
+    return await client.send(new ListStateMachinesCommand());
   }
   catch (e) {
     console.log(e);
-    res.send({error: e});
+    return {error: e};
   }  
-})
+}
+
+app.get('/machines', async (req, res) => {
+  res.send(await listMachines());
+});
+
+app.get('/machines/:name', async (req, res) => {
+  const name = req.params.name;
+
+  if (machines[name]) {
+    res.send(await client.send(new DescribeStateMachineCommand({stateMachineArn: machines[name]})));
+    return;
+  }
+
+  // Sending 404 when not found something is a good practice
+  res.status(404).send('State Machine not found');
+});
+
+app.get('/flow/start/:name', async (req, res) => {
+  const name = req.params.name;
+
+  if (!machines[name]) {
+    res.status(404).send('State Machine not found');
+    return;
+  }
+
+  res.send(await client.send(new StartExecutionCommand({stateMachineArn: machines[name]})));
+});
+
+app.post('/token', (req, res) => {
+  console.log(req.body);
+});
+
+const creation = setInterval(async () => {
+  const res = await listMachines();
+  if (!res.error) {
+    console.log("Creating State Machine");
+    fs.readFile("flow.asl.json", (err, data) => {
+      client.send(new CreateStateMachineCommand({
+        name: "workflow",
+        definition: data.toString('utf8'),
+        roleArn: "arn:aws:iam::128716708097:role/StepFunctionsLambdaRole"
+      })).then((r) => {
+        const key = r.stateMachineArn.split(":").pop();
+        machines[key] = r.stateMachineArn;
+        console.log(machines);
+      }).catch((e) => {
+        console.log(e);
+      })
+    });
+    clearInterval(creation);
+  }
+}, 5000);
 
 app.listen(port, () => console.log(`Hello world app listening on port ${port}!`));

source/SIL.AppBuilder.Portal.AWS.Step/flow.asl.json

@@ -0,0 +1,45 @@
+{
+  "Comment": "An example of the Amazon States Language using a choice state.",
+  "StartAt": "FirstState",
+  "States": {
+    "FirstState": {
+      "Type": "Task",
+      "Resource": "arn:aws:states:::http:invoke.waitForTaskToken",
+      "Parameters": {
+        "ApiEndpoint": "http://localhost:3000",
+        "Authentication": {
+          "ConnectionArn": "arn:aws:events:dummy:123456789012:connection"
+        },
+        "Method": "POST",
+        "Headers": {
+          "Content-Type": "application/json"
+        },
+        "RequestBody": {
+          "token.$": "$$.Task.Token"
+        }
+      },
+      "Next": "ChoiceState"
+    },
+    "ChoiceState": {
+      "Type" : "Choice",
+      "Choices": [
+        {
+          "Variable": "$.name",
+          "StringEquals": "test",
+          "Next": "SuccessState"
+        }
+      ],
+      "Default": "DefaultState"
+    },
+
+    "DefaultState": {
+      "Type": "Fail",
+      "Error": "DefaultStateError",
+      "Cause": "No Matches!"
+    },
+
+    "SuccessState": {
+      "Type": "Succeed"
+    }
+  }
+}