AWS Lambda Cheat Sheet

AWS Lambda is a serverless computing service provided by Amazon Web Services (AWS) that allows you to run your code without provisioning or managing servers. With Lambda, you can build applications that automatically scale with the number of requests, and you only pay for the compute time you consume. This blog post will provide a comprehensive AWS Lambda cheat sheet, covering advanced concepts and features that will help you make the most out of this powerful service.

Introduction to AWS Lambda

AWS Lambda enables developers to focus on writing their application logic without worrying about the underlying infrastructure. It supports multiple programming languages, including Python, Node.js, Java, and Go. With AWS Lambda, you can build applications that respond to events from various AWS services, such as Amazon S3, Amazon DynamoDB, and Amazon API Gateway.

Lambda Function Basics

Creating a Lambda Function

To create a Lambda function, follow these steps:

1. Sign in to the AWS Management Console and open the AWS Lambda console.
2. Select "Functions" from the left navigation pane, and click "Create function."
3. Choose the "Author from scratch" option, and provide the required information, such as the function name, runtime, and role.
4. Click "Create function" to finish the process.

You can also create a Lambda function using the AWS CLI, AWS SDKs, or AWS CloudFormation.

Invoking a Lambda Function

You can invoke a Lambda function using several methods:

• Synchronously: The caller waits for the function to complete execution and returns the response.
• Asynchronously: The caller doesn't wait for the function to complete, and AWS Lambda queues the event for processing.
• Using an event source: Lambda functions can be triggered by AWS services like S3, DynamoDB, or API Gateway.

Lambda Function Configuration

You can configure various settings for your Lambda function, such as:

• Memory: You can allocate between 128 MB and 3008 MB of memory in 64 MB increments. The CPU power, network bandwidth, and disk I/O are proportionally allocated based on the memory setting.
• Timeout: You can set the function timeout between 1 second and 15 minutes. If the function execution exceeds the timeout, it will be terminated.
• Environment variables: You can use environment variables to store configuration settings and secrets for your function.
• Dead Letter Queue (DLQ): You can configure a DLQ to handle failed asynchronous invocations and ensure that event data isn't lost.

Lambda Function Packages

A Lambda function package contains your code and any dependencies. You can create a deployment package using the following methods:

• Uploading a .zip or .jar file directly to the Lambda console.
• Uploading the package to an Amazon S3 bucket and providing the bucket name and object key.
• Using AWS Serverless Application Model (SAM) or AWS CloudFormation to package and deploy your function.

Lambda Layers

Lambda layers allow you to manage your function's code and dependencies separately. You can create a layer containing shared libraries, custom runtimes, or other function dependencies and then reference it in one or more Lambda functions. This approach promotes code sharing and separation of responsibilities.

AWS Lambda Event Sources

AWS Lambda supports various event sources that can trigger your Lambda function. These sources can be grouped into the following categories:

• AWS services: Amazon S3, Amazon DynamoDB, Amazon Kinesis, and others.
• Custom applications: You can create custom applications that generate events and invoke your Lambda function using AWS SDKs or the AWS CLI.
• API Gateway: You can create RESTful APIs using Amazon API Gateway and map the API endpoints to Lambda functions.

AWS Lambda Logging and Monitoring

AWS provides several tools to help you monitor and troubleshoot your Lambda functions:

• Amazon CloudWatch Logs: Lambda automatically streams function logs to CloudWatch Logs, allowing you to view and search log data.
• Amazon CloudWatch Metrics: Lambda emits metrics like invocation count, duration, and error rate to CloudWatch, enabling you to create custom dashboards and alarms.
• AWS X-Ray: This service allows you to trace and analyze requests as they flow through your Lambda function and other AWS services.

AWS Lambda Security

AWS Lambda provides various security features to protect your functions and data:

• IAM roles: You can use AWS Identity and Access Management (IAM) roles to control the permissions your Lambda function has when accessing other AWS services.
• VPC support: You can run your Lambda function inside an Amazon VPC to access resources like RDS or ElastiCache.
• Resource policies: You can define resource policies to control who can invoke your Lambda function.

Lambda Function Pricing

AWS Lambda follows a pay-as-you-go pricing model based on the number of requests and compute time. You are charged for the total number of requests and the duration of function execution in 1ms increments.

FAQ

Q: What is AWS Lambda?

A: AWS Lambda is a serverless computing service that allows you to run your code without provisioning or managing servers.

Q: How do I create a Lambda function?

A: You can create a Lambda function using the AWS Management Console, AWS CLI, AWS SDKs, or AWS CloudFormation.

Q: What programming languages does AWS Lambda support?

A: AWS Lambda supports multiple programming languages, including Python, Node.js, Java, and Go.

Q: How can I monitor the performance of my Lambda functions?

A: You can use Amazon CloudWatch Logs, Amazon CloudWatch Metrics, and AWS X-Ray to monitor and troubleshoot your Lambda functions.

Q: How is AWS Lambda billed?

A: AWS Lambda follows a pay-as-you-go pricing model based on the number of requests and compute time.

This AWS Lambda cheat sheet has provided an in-depth overview of the advanced concepts and features of the service. For more information and resources, visit the official AWS Lambda documentation.