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To interact with AWS Lambda using the AWS SDK in JavaScript, you can import the SDK, initialize an AWS Lambda client, and invoke a Lambda function with a custom payload. The AWS Lambda client handles potential errors and success cases by calling context.done in case of an error and context.succeed with the payload in case of a successful function call.

Cell 2

var aws = require('aws-sdk');
var lambda = new aws.Lambda({
  region: 'us-west-2' //change to your region
});

lambda.invoke({
  FunctionName: 'name_of_your_lambda_function',
  Payload: JSON.stringify(event, null, 2) // pass params
}, function(error, data) {
  if (error) {
    context.done('error', error);
  }
  if(data.Payload){
   context.succeed(data.Payload)
  }
});

What the code could have been:

/**
 * Import the required AWS SDK and set the region.
 * @type {Object} aws - AWS SDK instance
 */
const { Lambda } = require('aws-sdk');
const lambda = new Lambda({
  region: process.env.AWS_REGION || 'us-west-2', // Use AWS_REGION env var if set, default to us-west-2
});

/**
 * Invoke the Lambda function with the provided event data.
 * @param {Object} event - Event data to pass to the Lambda function
 * @param {Function} callback - Callback function to handle the response
 */
function invokeLambda(event, callback) {
  const params = {
    FunctionName: 'name_of_your_lambda_function',
    Payload: JSON.stringify(event, null, 2), // pass params
  };

  lambda.invoke(params, (error, data) => {
    if (error) {
      callback('error', error);
    } else if (data.Payload) {
      callback(null, data.Payload);
    } else {
      callback('error', new Error('No payload in response')); // Add error handling for unexpected response
    }
  });
}

// Example usage
invokeLambda(event, (error, result) => {
  if (error) {
    console.error(error); // Log errors to cloudwatch
  } else {
    console.log(result); // Log successful response to cloudwatch
  }
});

Code Breakdown

Importing AWS SDK

var aws = require('aws-sdk');

Imports the AWS SDK.

Initializing AWS Lambda Client

var lambda = new aws.Lambda({
  region: 'us-west-2' // change to your region
});

Creates a new client instance for AWS Lambda in the specified region.

Invoking a Lambda Function

lambda.invoke({
  FunctionName: 'name_of_your_lambda_function', // replace with your function name
  Payload: JSON.stringify(event, null, 2) // pass params
}, function(error, data) {
 ...
});

Invokes the specified Lambda function with the provided payload, which is a JSON stringified version of the event object.

Error and Success Handling

if (error) {
  context.done('error', error);
}
if (data.Payload) {
  context.succeed(data.Payload)
}

Handles potential errors and success cases.