feat(Typescript): StepFunctions CRON example (#336)

* Add step functions cron example for typescript * Update message * Update deprecated code * Fix wrong name * Update stepfunctions-job-poller example with cron job * fix: reduced wait `300` -> `30` to prevent timeout, clean spacing, added graph and steps to README * revert rename of `README` -> `REAMDE` Co-authored-by: Ryan Parker <[email protected]>
aws-samples · Jul 9, 2021 · 9bf9953 · 9bf9953
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diff --git a/.editorconfig b/.editorconfig
@@ -0,0 +1,13 @@
+# EditorConfig is awesome: https://EditorConfig.org
+root = true
+
+[*]
+indent_style = space
+indent_size = 2
+end_of_line = lf
+charset = utf-8
+trim_trailing_whitespace = true
+insert_final_newline = true
+
+[.py]
+indent_size = 4
diff --git a/typescript/stepfunctions-job-poller/README.md b/typescript/stepfunctions-job-poller/README.md
@@ -1,29 +1,47 @@
-# Stepfunctions Job Poller
+# Step Functions Job Poller
+
 <!--BEGIN STABILITY BANNER-->
 ---
 
 ![Stability: Experimental](https://img.shields.io/badge/stability-Experimental-important.svg?style=for-the-badge)
 
 > **This is an experimental example. It may not build out of the box**
 >
-> This examples does is built on Construct Libraries marked "Experimental" and may not be updated for latest breaking changes.
+> This examples is built on Construct Libraries marked "Experimental" and may not be updated for latest breaking changes.
 >
-> If build is unsuccessful, please create an [issue](https://github.com/aws-samples/aws-cdk-examples/issues/new) so that we may debug the problem 
+> If build is unsuccessful, please create an [issue](https://github.com/aws-samples/aws-cdk-examples/issues/new) so that we may debug the problem
 
 ---
 <!--END STABILITY BANNER-->
 
-This example creates a basic Stepfunction workflow that starts a task and then listens at regular intervals for completion, then reports completion and status.
+This example creates a basic Step Function workflow that starts a task and then listens at regular intervals for completion, then reports completion and status.
+
+<kbd>
+<img src="./step-function-graph.png" width="500px" margin="auto" />
+</kbd>
+
+Tasks:
 
+1. `Start`
+2. `Submit Lambda`: Invoke Submit Lambda which sets status
+3. `Wait X Seconds`: Wait
+4. `Get Job Status`: Invoke Check Status Lambda which validates status
+5. `Job Complete?`: Choice: Read `"status"` of payload
+   a. If `"status"` is `"SUCCEEDED"` then continue to `#7 Get Final Job Status` task
+   b. If `"status"` is `"FAILED"` then continue to `#6 Job Failed` task
+   c. else return to task `#3 Wait X Seconds`
+6. `Job Failed`: Define a Fail state in the state machine.
+7. `Get Final Job Status`: Invoke Check Status Lambda
+8. `End`
 
 ## Build
 
 To build this app, you need to be in this example's root folder. Then run the following:
 
 ```bash
-npm install -g aws-cdk
-npm install
-npm run build
+$ npm install -g aws-cdk
+$ npm install
+$ npm run build
 ```
 
 This will install the necessary CDK, then this example's dependencies, and then build your TypeScript files and your CloudFormation template.

diff --git a/typescript/stepfunctions-job-poller/index.ts b/typescript/stepfunctions-job-poller/index.ts
@@ -1,50 +1,91 @@
-import cdk = require('@aws-cdk/core');
-import sfn = require('@aws-cdk/aws-stepfunctions');
-import sfn_tasks = require('@aws-cdk/aws-stepfunctions-tasks');
+import * as cdk from '@aws-cdk/core';
+import * as lambda from '@aws-cdk/aws-lambda';
+import * as sfn from '@aws-cdk/aws-stepfunctions';
+import * as tasks from '@aws-cdk/aws-stepfunctions-tasks';
+import * as events from '@aws-cdk/aws-events';
+import * as targets from '@aws-cdk/aws-events-targets';
+import * as fs from 'fs'
 
 class JobPollerStack extends cdk.Stack {
-    constructor(scope: cdk.App, id: string, props: cdk.StackProps = {}) {
-        super(scope, id, props);
-
-        const submitJobActivity = new sfn.Activity(this, 'SubmitJob');
-        const checkJobActivity = new sfn.Activity(this, 'CheckJob');
-
-        const submitJob = new sfn.Task(this, 'Submit Job', {
-            task: new sfn_tasks.InvokeActivity(submitJobActivity),
-            resultPath: '$.guid',
-        });
-        const waitX = new sfn.Wait(this, 'Wait X Seconds', { 
-            time: sfn.WaitTime.secondsPath('$.wait_time') 
-        });
-        const getStatus = new sfn.Task(this, 'Get Job Status', {
-            task: new sfn_tasks.InvokeActivity(checkJobActivity),
-            inputPath: '$.guid',
-            resultPath: '$.status',
-        });
-        const isComplete = new sfn.Choice(this, 'Job Complete?');
-        const jobFailed = new sfn.Fail(this, 'Job Failed', {
-            cause: 'AWS Batch Job Failed',
-            error: 'DescribeJob returned FAILED',
-        });
-        const finalStatus = new sfn.Task(this, 'Get Final Job Status', {
-            task: new sfn_tasks.InvokeActivity(checkJobActivity),
-            inputPath: '$.guid',
-        });
-
-        const chain = sfn.Chain
-            .start(submitJob)
-            .next(waitX)
-            .next(getStatus)
-            .next(isComplete
-                .when(sfn.Condition.stringEquals('$.status', 'FAILED'), jobFailed)
-                .when(sfn.Condition.stringEquals('$.status', 'SUCCEEDED'), finalStatus)
-                .otherwise(waitX));
-
-        new sfn.StateMachine(this, 'StateMachine', {
-            definition: chain,
-            timeout: cdk.Duration.seconds(30)
-        });
-    }
+  constructor(app: cdk.App, id: string) {
+    super(app, id);
+
+    /** ------------------ Lambda Handlers Definition ------------------ */
+
+    const getStatusLambda = new lambda.Function(this, 'CheckLambda', {
+      code: new lambda.InlineCode(fs.readFileSync('lambdas/check_status.py', { encoding: 'utf-8' })),
+      handler: 'index.main',
+      timeout: cdk.Duration.seconds(30),
+      runtime: lambda.Runtime.PYTHON_3_6,
+    });
+
+    const submitLambda = new lambda.Function(this, 'SubmitLambda', {
+      code: new lambda.InlineCode(fs.readFileSync('lambdas/submit.py', { encoding: 'utf-8' })),
+      handler: 'index.main',
+      timeout: cdk.Duration.seconds(30),
+      runtime: lambda.Runtime.PYTHON_3_6,
+    });
+
+    /** ------------------ Step functions Definition ------------------ */
+
+    const submitJob = new tasks.LambdaInvoke(this, 'Submit Job', {
+      lambdaFunction: submitLambda,
+      // Lambda's result is in the attribute `Payload`
+      outputPath: '$.Payload',
+    });
+    const waitX = new sfn.Wait(this, 'Wait X Seconds', {
+      /**
+       *  You can also implement with the path stored in the state like:
+       *  sfn.WaitTime.secondsPath('$.waitSeconds')
+       */
+      time: sfn.WaitTime.duration(cdk.Duration.seconds(30)),
+    });
+    const getStatus = new tasks.LambdaInvoke(this, 'Get Job Status', {
+      lambdaFunction: getStatusLambda,
+      outputPath: '$.Payload',
+    });
+
+    const jobFailed = new sfn.Fail(this, 'Job Failed', {
+      cause: 'AWS Batch Job Failed',
+      error: 'DescribeJob returned FAILED',
+    });
+
+    const finalStatus = new tasks.LambdaInvoke(this, 'Get Final Job Status', {
+      lambdaFunction: getStatusLambda,
+      outputPath: '$.Payload',
+    });
+
+    // Create chain
+    const definition = submitJob
+      .next(waitX)
+      .next(getStatus)
+      .next(new sfn.Choice(this, 'Job Complete?')
+        // Look at the "status" field
+        .when(sfn.Condition.stringEquals('$.status', 'FAILED'), jobFailed)
+        .when(sfn.Condition.stringEquals('$.status', 'SUCCEEDED'), finalStatus)
+        .otherwise(waitX));
+
+    // Create state machine
+    const stateMachine = new sfn.StateMachine(this, 'CronStateMachine', {
+      definition,
+      timeout: cdk.Duration.minutes(5),
+    });
+
+    // Grant lambda execution roles
+    submitLambda.grantInvoke(stateMachine.role);
+    getStatusLambda.grantInvoke(stateMachine.role);
+
+    /** ------------------ Events Rule Definition ------------------ */
+
+    /**
+     *  Run every day at 6PM UTC
+     * See https://docs.aws.amazon.com/lambda/latest/dg/tutorial-scheduled-events-schedule-expressions.html
+     */
+    const rule = new events.Rule(this, 'Rule', {
+      schedule: events.Schedule.expression('cron(0 18 ? * MON-FRI *)')
+    });
+    rule.addTarget(new targets.SfnStateMachine(stateMachine));
+  }
 }
 
 const app = new cdk.App();

diff --git a/typescript/stepfunctions-job-poller/lambdas/check_status.py b/typescript/stepfunctions-job-poller/lambdas/check_status.py
@@ -0,0 +1,5 @@
+def main(event, context):
+    if event["status"] == "SUCCEEDED":
+        return {"status": "SUCCEEDED", "id": event["id"]}
+    else:
+        return {"status": "FAILED", "id": event["id"]}
diff --git a/typescript/stepfunctions-job-poller/lambdas/submit.py b/typescript/stepfunctions-job-poller/lambdas/submit.py
@@ -0,0 +1,7 @@
+def main(event, context):
+    print('The job is submitted successfully!')
+    # Return the handling result
+    return {
+        "id": event['id'],
+        "status": "SUCCEEDED",
+    }
diff --git a/typescript/stepfunctions-job-poller/package.json b/typescript/stepfunctions-job-poller/package.json
@@ -15,10 +15,13 @@
   },
   "license": "Apache-2.0",
   "devDependencies": {
-    "@types/node": "^10.17.0",
-    "typescript": "~3.7.2"
+    "@types/node": "*",
+    "typescript": "^3.8"
   },
   "dependencies": {
+    "@aws-cdk/aws-events": "*",
+    "@aws-cdk/aws-events-targets": "*",
+    "@aws-cdk/aws-lambda": "*",
     "@aws-cdk/aws-stepfunctions": "*",
     "@aws-cdk/aws-stepfunctions-tasks": "*",
     "@aws-cdk/core": "*"

diff --git a/typescript/stepfunctions-job-poller/step-function-graph.png b/typescript/stepfunctions-job-poller/step-function-graph.png
diff --git a/typescript/stepfunctions-job-poller/tsconfig.json b/typescript/stepfunctions-job-poller/tsconfig.json
@@ -1,21 +1,27 @@
 {
-    "compilerOptions": {
-        "target":"ES2018",
-        "module": "commonjs",
-        "lib": ["es2016", "es2017.object", "es2017.string"],
-        "strict": true,
-        "noImplicitAny": true,
-        "strictNullChecks": true,
-        "noImplicitThis": true,
-        "alwaysStrict": true,
-        "noUnusedLocals": true,
-        "noUnusedParameters": true,
-        "noImplicitReturns": true,
-        "noFallthroughCasesInSwitch": false,
-        "inlineSourceMap": true,
-        "inlineSources": true,
-        "experimentalDecorators": true,
-        "strictPropertyInitialization":false
-    }
+  "compilerOptions": {
+    "target": "ES2018",
+    "module": "commonjs",
+    "lib": [
+      "es2016",
+      "es2017.object",
+      "es2017.string"
+    ],
+    "strict": true,
+    "noImplicitAny": true,
+    "strictNullChecks": true,
+    "noImplicitThis": true,
+    "alwaysStrict": true,
+    "noUnusedLocals": true,
+    "noUnusedParameters": true,
+    "noImplicitReturns": true,
+    "noFallthroughCasesInSwitch": false,
+    "inlineSourceMap": true,
+    "inlineSources": true,
+    "experimentalDecorators": true,
+    "strictPropertyInitialization": false
+  },
+  "exclude": [
+    "cdk.out"
+  ]
 }
-