sls-step-functions template: Serverless multiple Lambda orchestration…

… workflow Using AWS Step Functions

sls-step-functions/.npmignore

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+# package directories
+node_modules
+jspm_packages
+
+# Serverless directories
+.serverless

sls-step-functions/README.md

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+### Serverless Orchestration Workflows with AWS Step Functions using Serverless Framework
+
+In this template, we demonstrate below AWS services:
+- AWS Step Functions
+- AWS Lambda
+
+Use Cases Covered:
+- Serverless multiple Lambda orchestration workflow with AWS Step Functions
+
+### This Serverless Framework template IaC will create
+- 1 State Machine with Standard type Workflow with different states e.g Choice, Task, etc.
+- 4 Lambda Functions (add, subtract, multiply, validateResult)
+
+### This POC Demo Step Function standard workflow works like this
+1. Step Function workflow Start with Choice state
+
+2. Based on choice states 'operation' input, do call different steps of lambda tasks e.g add, subtract, multiply
+
+3. add, subtract, multiply tasks lambda step will call 'validateResult' lambda task
+
+4. 'validateResult' lambda task checks this
+
+- 4.1. From add, subtract, multiply step 'resultNumber' > 100 then raise exception 'NumberIsBig' which will catch by 'NumberIsBig' fail step
+- 4.2. Incase 'resultNumber' not valid then return 'InvalidNumberError' exception
+- 4.3. resultNumber < 0 will raise exception with timeout
+- 4.4. For other success scenario it will return success 'resultNumber'
+
+### Steps Functions State Machine Execution Cases
+
+1. Case - add - Succeeded
+    1. Input JSON Value: { "number1": 5, "number2": 2, "operation": "add" }
+    2. Result Success ["output": 7]
+
+2. Case - add - Failed
+    1. Input JSON Value: { "number1": 99, "number2": 2, "operation": "add" }
+    2. Result Failed [output resultNumber > 100]
+
+3. Case - subtract - Succeeded
+    1. Input JSON Value: { "number1": 5, "number2": 2, "operation": "subtract" }
+    2. Result Success ["output": 3]    
+
+4. Case - multiply - Succeeded
+    1. Input JSON Value: { "number1": 5, "number2": 2, "operation": "multiply" }
+    2. Result Success ["output": 10]
+
+5. Case - multiply - Failed
+    1. Input JSON Value: { "number1": 15, "number2": 7, "operation": "multiply" }
+    2. Result Failed [output resultNumber > 100]

sls-step-functions/functions/add.js

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+module.exports.handler = async (event, context) => {
+  return event.number1 + event.number2;
+};

sls-step-functions/functions/multiply.js

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+module.exports.handler = async (event, context) => {
+  return event.number1 * event.number2;
+};

sls-step-functions/functions/subtract.js

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+module.exports.handler = async (event, context) => {
+  return event.number1 - event.number2;
+};

sls-step-functions/functions/validateResult.js

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+function InvalidNumberError(resultVar) {
+  this.name = 'InvalidNumberError';
+  this.message = `${resultVar} is not a number!`;
+}
+InvalidNumberError.prototype = new Error();
+
+function NumberIsBig(resultVar, max) {
+  this.name = 'NumberIsBig';
+  this.message = `${resultVar} is bigger than ${max}!`;
+}
+NumberIsBig.prototype = new Error();
+
+module.exports.handler = async (resultNumber, context) => {
+  if (!resultNumber) {
+    //Just for  Proof of concept demo throw 'InvalidNumberError' exception when result number in invalid
+    throw new InvalidNumberError("resultNumber");
+  } else if (resultNumber > 100) {
+    //Just for  Proof of concept demo throw 'NumberIsBig' exception when result number is greater then 100
+    throw new NumberIsBig("resultNumber", 100);
+  } else if (resultNumber < 0) {
+    //Just for  Proof of concept demo represent timeout step
+    while (true) {
+      // let it timeout
+    }
+  } else {
+    return resultNumber;
+  }
+};