Initial version of the library

Author: Kolomiets

.eslintignore

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+node_modules
+lib

.github/workflows/build.yml

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+name: build
+
+on:
+  push:
+    branches: [ master ]
+  pull_request:
+    branches: [ master ]
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    
+    strategy:
+      matrix:
+        node-version: [12.x]
+
+    steps:
+    - uses: actions/checkout@v2
+    - name: Use Node.js ${{ matrix.node-version }}
+      uses: actions/setup-node@v1
+      with:
+        node-version: ${{ matrix.node-version }}
+        
+    - run: npm install
+    - run: npm run build --if-present
+    - run: npm test

.github/workflows/jsii-pre-publish.yml

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+name: jsii-pre-publish checks
+
+on:
+  push:
+    branches:
+      - "*"
+    tags-ignore:
+      - "v*"
+  pull_request:
+    branches: [ master ]
+
+jobs:
+  build:
+
+    runs-on: ubuntu-latest
+
+    strategy:
+      matrix:
+        node-version: [12.x]
+
+    steps:
+    - uses: actions/checkout@v2
+      with:
+        fetch-depth: 1
+
+    - name: Use Node.js ${{ matrix.node-version }}
+      uses: actions/setup-node@v1
+      with:
+        node-version: ${{ matrix.node-version }}
+
+    - run: make

.github/workflows/jsii-publish.yml

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+name: jsii-publish
+
+on:
+  push:
+    tags:
+      - "v*"
+
+jobs:
+  build:
+
+    runs-on: ubuntu-latest
+
+    strategy:
+      matrix:
+        node-version: [12.x]
+
+    steps:
+    - uses: actions/checkout@v2
+      with:
+        fetch-depth: 1
+
+    - name: Use Node.js ${{ matrix.node-version }}
+      uses: actions/setup-node@v1
+      with:
+        node-version: ${{ matrix.node-version }}
+
+    - run: make
+
+    - run: make publish-npm
+      env:
+        NPM_TOKEN: ${{ secrets.NPM_TOKEN }}
+
+    - run: make publish-pypi
+      env:
+        PYPI_TOKEN: ${{ secrets.PYPI_TOKEN }}
+
+    - run: make publish-nuget
+      env:
+        NUGET_API_KEY: ${{ secrets.NUGET_API_KEY }}
+
+    # - run: make publish-maven
+    #   env:
+    #     MAVEN_STAGING_PROFILE_ID: ${{ secrets.MAVEN_STAGING_PROFILE_ID }}
+    #     MAVEN_USERNAME: ${{ secrets.MAVEN_USERNAME }}
+    #     MAVEN_PASSWORD: ${{ secrets.MAVEN_PASSWORD }}
+    #     MAVEN_GPG_PRIVATE_KEY: ${{ secrets.MAVEN_GPG_PRIVATE_KEY }}
+    #     MAVEN_GPG_PRIVATE_KEY_PASSPHRASE: ${{ secrets.MAVEN_GPG_PRIVATE_KEY_PASSPHRASE }}

.gitignore

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+# npm
+node_modules/
+.npm
+*.tgz
+
+# code coverage
+coverage/
+
+# jsii
+tsconfig.json
+.jsii
+dist/
+*.js
+*.d.ts
+.cdk.staging
+
+lib/resources/

.npmignore

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+
+# Exclude typescript source and config
+*.ts
+tsconfig.json
+
+# Include javascript files and typescript declarations
+!*.js
+!*.d.ts
+
+# Exclude jsii outdir
+dist
+
+# Exclude lambda dir
+lambda
+
+# Include .jsii
+!.jsii

Makefile

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+SHELL := /bin/bash -o pipefail
+
+DOCKER_IMAGE := jsii/superchain
+DOCKER_TAG := latest
+DOCKER_WORKDIR := /workdir
+
+build:
+	docker run \
+		--workdir ${DOCKER_WORKDIR} \
+		--volume ${PWD}:${DOCKER_WORKDIR} \
+		${DOCKER_IMAGE}:${DOCKER_TAG} \
+		/bin/bash -c "rm -rf dist && npm i && npm run package"
+
+publish-npm:
+	docker run \
+		--workdir ${DOCKER_WORKDIR} \
+		--volume ${PWD}:${DOCKER_WORKDIR} \
+		--env NPM_TOKEN \
+		${DOCKER_IMAGE}:${DOCKER_TAG} \
+		/bin/bash -c "npx jsii-release-npm dist/js"
+
+publish-nuget:
+	docker run \
+		--workdir ${DOCKER_WORKDIR} \
+		--volume ${PWD}:${DOCKER_WORKDIR} \
+		--env NUGET_API_KEY \
+		${DOCKER_IMAGE}:${DOCKER_TAG} \
+		/bin/bash -c "npx jsii-release-nuget dist/dotnet"
+		
+publish-pypi:
+	docker run \
+		--workdir ${DOCKER_WORKDIR} \
+		--volume ${PWD}:${DOCKER_WORKDIR} \
+		--env TWINE_USERNAME=__token__ \
+		--env TWINE_PASSWORD=$(PYPI_TOKEN) \
+		${DOCKER_IMAGE}:${DOCKER_TAG} \
+		/bin/bash -c "npx jsii-release-pypi dist/python"
+		
+publish-maven:
+	docker run \
+		--workdir ${DOCKER_WORKDIR} \
+		--volume ${PWD}:${DOCKER_WORKDIR} \
+		--env MAVEN_STAGING_PROFILE_ID \
+		--env MAVEN_USERNAME \
+		--env MAVEN_PASSWORD \
+		--env MAVEN_GPG_PRIVATE_KEY \
+		--env MAVEN_GPG_PRIVATE_KEY_PASSPHRASE \
+		--env MAVEN_DRYRUN \
+		${DOCKER_IMAGE}:${DOCKER_TAG} \
+		/bin/bash -c "npx jsii-release-maven dist/java"

README.md

@@ -1,2 +1,14 @@
 # cdk-stepfunctions-patterns
-A set of Step Functions high-level patterns.
+![build](https://github.com/kolomied/cdk-stepfunctions-patterns/workflows/build/badge.svg)
+![jsii-publish](https://github.com/kolomied/cdk-stepfunctions-patterns/workflows/jsii-publish/badge.svg)
+![downloads](https://img.shields.io/npm/dt/cdk-stepfunctions-patterns)
+
+[![npm version](https://badge.fury.io/js/cdk-stepfunctions-patterns.svg)](https://badge.fury.io/js/cdk-stepfunctions-patterns)
+[![PyPI version](https://badge.fury.io/py/cdk-stepfunctions-patterns.svg)](https://badge.fury.io/py/cdk-stepfunctions-patterns)
+[![NuGet version](https://badge.fury.io/nu/Talnakh.StepFunctions.Patterns.svg)](https://badge.fury.io/nu/Talnakh.StepFunctions.Patterns)
+
+A simple CDK seeder for SQL Server RDS databases.
+
+*cdk-stepfunctions-patterns* library is a set of [AWS CDK](https://aws.amazon.com/cdk/) constructs that provide 
+resiliency patterns implementation for AWS Step Functions.
+

lambda/jitter/main.py

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+import random
+
+class Backoff:
+    def __init__(self, base, backoff, cap):
+        self.base = base
+        self.backoff = backoff
+        self.cap = cap
+
+    def expo(self, n):
+      return min(self.cap, pow(self.backoff, n) * self.base)
+      
+    def backoff(self, n):
+      v = self.expo(n)
+      return random.uniform(0, v)
+
+    def decor(self, n):
+      sleep = self.backoff(n)
+      return min(cap, random.uniform(self.base, sleep * 3))
+
+def lambda_handler(event, context):
+  n = event.get("RetryCount", 0)
+  base = event.get("Interval", 1)
+  backoff = event.get("Backoff", 2)
+
+  fullBackoff = Backoff(base, backoff, 200)
+  return round(fullBackoff.backoff(n))

lib/aspect/ResilienceLambdaChecker.ts

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+import * as cdk from '@aws-cdk/core';
+import * as tasks from '@aws-cdk/aws-stepfunctions-tasks';
+import { RetryProps } from '@aws-cdk/aws-stepfunctions'
+import { ResilientLambdaTask } from '../construct/ResilientLambdaTask'
+
+export interface ResilienceLambdaCheckerProps {
+    readonly fail?: boolean;
+}
+
+export class ResilienceLambdaChecker implements cdk.IAspect {
+
+  private readonly _fail?: boolean;
+
+  constructor(props?: ResilienceLambdaCheckerProps) {
+    this._fail = props?.fail
+  }
+
+  public visit(construct: cdk.IConstruct): void {
+
+    if (construct instanceof tasks.LambdaInvoke) {
+      const reporter = this._fail ? construct.node.addError : construct.node.addWarning;
+
+      const retries = this.getRetryConfiguration(construct);
+      if (retries.length > 0) {
+        const unhandledErrors = this.getUnhandledTransientErrors(retries);
+
+        if (unhandledErrors.length > 0) {
+          reporter.apply(construct.node, [`Missing retry for transient errors: ${unhandledErrors}.`]);
+        }
+      } else {
+        reporter.apply(construct.node, ['No retry for AWS Lambda transient errors defined - consider using ResilientLambdaTask construct.']);
+        //ResilientLambdaTask.addDefaultRetry(construct);
+      }
+    }
+  }
+
+  private getUnhandledTransientErrors(retries: Array<RetryProps>): Array<string> {
+    return ResilientLambdaTask.TransientErrors.filter(transientError => 
+      retries.every(config => !config.errors?.includes(transientError)));
+  }
+
+  private getRetryConfiguration(construct: cdk.IConstruct): Array<RetryProps> {
+    // eslint-disable-next-line @typescript-eslint/no-explicit-any
+    return (construct as any).retries as Array<RetryProps> || []
+  }
+}

lib/construct/ResilientLambdaTask.ts

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+import * as cdk from '@aws-cdk/core';
+import * as tasks from '@aws-cdk/aws-stepfunctions-tasks';
+
+export class ResilientLambdaTask extends tasks.LambdaInvoke {
+
+  public static readonly TransientErrors: string[] = [
+    "Lambda.ServiceException",
+    "Lambda.AWSLambdaException",
+    "Lambda.SdkClientException",
+    "Lambda.TooManyRequestsException"
+  ]
+
+  constructor(scope: cdk.Construct, id: string, props: tasks.LambdaInvokeProps) {
+    super(scope, id, props)
+    ResilientLambdaTask.addDefaultRetry(this);
+  }
+
+  public static addDefaultRetry(task: tasks.LambdaInvoke): void {
+    // https://docs.aws.amazon.com/step-functions/latest/dg/bp-lambda-serviceexception.html
+    task.addRetry({
+      errors: ResilientLambdaTask.TransientErrors,
+      backoffRate: 2,
+      maxAttempts: 6,
+      interval: cdk.Duration.seconds(2)
+    });
+  }
+}