amazon-web-servicesaws-lambdaaws-step-functions

How to call a step funtion from Node.js Lambda function?


I am trying to call a step function from a Node.js lambda function. I tried the solution and updated implementations from this thread.

The solution showing the error response but the updated code showing success response. But the updated code is not calling the step function.

My Code:


console.log('Loading function');
const AWS = require('aws-sdk');
exports.handler = function(event, context) {
    console.log('Loading step functions');
    const stepFunctions = new AWS.StepFunctions({
    region: 'us-east-2'
});
console.log('Loading init');
module.exports.init = (event, context, callback) => {
console.log('Loading params');
const params = {
        stateMachineArn: 'ARN of My State Machine',
        // input: JSON.stringify({}), Optional if your statemachine requires an application/json input, make sure its stringified 
        name: 'TestExecution' // name can be anything you want, but it should change for every execution
    };

console.log('start step functions');
stepFunctions.startExecution(params, (err, data) => {
        if (err) {
            console.log(err);
            const response = {
                statusCode: 500,
                body: JSON.stringify({
                    message: 'There was an error'
                })
            };
            callback(null, response);
        } else {
            console.log(data);
            const response = {
                statusCode: 200,
                body: JSON.stringify({
                    message: 'Step function worked'
                })
            };
            callback(null, response);
            console.log(response);
        }
    });
    };
};

I have added the above code in a Lambda function and Deploy the codes. After that I have used the Test option of the lambda function. Is that the right way of executing a Lambda function? The test result is success, but when I check the state machine, there are no recent executions. Help me to find a solution for this, I am very new to step function. Thanks in advance.


Solution

  • Here are the things I did:

    Below is my code for calling the step function:

    var aws = require('aws-sdk')
    exports.handler = (event, context, callback) => {
      var params = {
        stateMachineArn: 'arn:aws:states:us-east-1:1234567890:stateMachine:Helloworld',
        input: JSON.stringify({})
      };
      var stepfunctions = new aws.StepFunctions()
      stepfunctions.startExecution(params, (err, data) => {
        if (err) {
        console.log(err);
        const response = {
            statusCode: 500,
            body: JSON.stringify({
            message: 'There was an error'
            })
        };
        callback(null, response);
        } else {
        console.log(data);
        const response = {
            statusCode: 200,
            body: JSON.stringify({
            message: 'Step function worked'
            })
        };
        callback(null, response);
        }
    });
    }
    

    Lambda Execution Logs

    enter image description here

    Step Function Execution Logs

    enter image description here