从在本地系统而非 S3 上运行的 node.js 应用程序调用 AWS Lambda

Question

I would like to invoke AWS Lambda from a node.js file receding on my system. I followed Invoking a Lambda Function in a Browser Script and created a Congnito Identity Pool for Unauthenticated user and embedded the IdentityPoolId in the node js file like below:

 let AWS = require('aws-sdk'); AWS.config.region = '<my-region>'; let lambda = new AWS.Lambda(); AWS.config.credentials = new AWS.CognitoIdentityCredentials({ IdentityPoolId: '<my-identity-pool-id>' }); let params = { FunctionName: '<my-lambda-function>', InvocationType: 'RequestResponse', LogType: 'Tail', Payload: '{ "name": "my-name" }' } lambda.invoke(params, (err, data) => { if (err) { console.log(err); } else { if (data.Payload) { console.log('my-lambda-function said: ' + data.Payload); } } });

My Lambda Function:

 exports.handler = function(event, context) { context.succeed('Hello ' + event.name); };

I have created an IAM Role with AWSLambdaExecute, AWSLambdaBasicExecutionRole and AmazonCognitoReadOnly policies attached and I am using the same role while creating Lambda as well as I have updated the same roles in the Identity Pool I have created in Cognito for Unauthorized access.

When I run node app.js all I get is the error: UnrecognizedClientException: The security token included in the request is invalid.

Can somebody point me in the right direction to invoke an AWS lambda by writing a simple NodeJS file on my local system without uploading any HTML/CSS/JS files in an S3 Bucket and without using AccessKeyID, SecretKeyId, Just using roles associated with Lambda.

Thanks in Advance.

Answer 1

There are many ways to invoke a Lambda Function.

• AWS services events (example: SNS triggered)
• API created through AWS API Gateway.
• Amazon CloudWatch cron jobs
• API calls leveraging AWS Lambda APIs.

If your aim is to use your function as API, which can send and receive request and responses, You probably should go for API Gateway Integration.

It's super easy to get started with API Gateway.

• Get your Lambda function ready.

• Set Up an IAM Role and Policy for an API to Invoke Lambda Functions

  { "Version": "2012-10-17", "Statement": [ { "Effect": "Allow", "Action": "lambda:InvokeFunction", "Resource": "*" } ] }

• Create API Resources for the Lambda Function

  1. In the API Gateway console, create an API.

  2. Create the /ResourceName resource off the API's root.

  3. Create a GET or POST method based on you requirements.

  4. Choose AWS Service for Integration type and Select Lambda Function you created in the respective region.

• Now, you can customize integration Request based on your requirements with body mapping templates .

• You may look into detailed documentation for API Gateway Integration with Lambda :

  In this section, we walk you through the steps to integrate an API with a Lambda function using the AWS Service and Lambda Function integration types.

• Once, your test invocation succeeds, you can then use the API invocation URL from API_NAME/Dashboard , which will look something like:

   https:// ###****.execute-api.us-west-2.amazonaws.com/{APIStageName}/ 

which can be used as REST endpoint and can be called from your Node js function locally. Don't forget to enable authentication for your API with API keys.

Also, go through Production Checklist, if you are going to use it in Such Environment.

Answer 2

I had the same issue, and I was able to resolve it using a Kinesis Stream. the Lambda function was acting as consumer. you have to create a trigger for the Lambda function as follows:

 function createTrigger (kinesisArn, lambdaName) { // Create params const for trigger const params = { EventSourceArn: kinesisArn, FunctionName: lambdaName, StartingPosition: 'LATEST', BatchSize: 100 } return new Promise((resolve, reject) => { lambda.createEventSourceMapping(params, (err, data) => { if (err) reject(err) else resolve(data) }) }) }

each time a new piece of data is being pushed on the Kinesis stream, your Lambda function will be called.

here is an example of how sending data on AWS Kinesis stream:

 function send(streamName, partition, msg) { const params = { Data: JSON.stringify(msg), // data you want to send to your Lambda function PartitionKey: partition, // an id for each shard StreamName: streamName } return new Promise((resolve, reject) => { kinesis.putRecord(params, (err, data) => { if(err) reject(err) else resolve(data); }) }); }