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AWS Lambda API Essential Guide

Aug 2, 20246 minute read

What type of API does AWS Lambda provide?

AWS Lambda does not have a specific API type like REST, GraphQL, or SOAP. Instead, Lambda is a serverless compute service that can be integrated with different API types and used to implement various API architectures. Here are the key points to consider:

Lambda's Flexibility

  1. Lambda functions can be triggered by various events, including HTTP requests through API Gateway, allowing them to be used in different API architectures.

  2. Lambda can be used to implement business logic for REST APIs, GraphQL APIs, or even SOAP APIs, depending on how it's configured and integrated with other AWS services.

Common API Architectures with Lambda

  1. REST APIs: Lambda is commonly used with Amazon API Gateway to create RESTful APIs. API Gateway handles the HTTP routing, and Lambda functions implement the business logic for each endpoint.

  2. GraphQL APIs: Lambda can be used as a resolver for GraphQL APIs, either through a self-managed GraphQL server running on Lambda or as part of AWS AppSync.

  3. SOAP to REST conversion: Lambda can be used to transform SOAP requests to REST and vice versa, acting as a bridge between legacy SOAP services and modern REST APIs.

Integration with API Gateway and AppSync

  1. API Gateway: Provides a managed service for creating, publishing, and managing APIs. It can be used to create REST and HTTP APIs that invoke Lambda functions.

  2. AppSync: A fully managed service for developing GraphQL APIs. It can use Lambda functions as resolvers for GraphQL queries and mutations.

Key Considerations

  1. Lambda's role: Lambda functions provide the compute layer and business logic for APIs, regardless of the API type.

  2. Flexibility: Developers can choose to implement various API types using Lambda, depending on their specific requirements and the other AWS services they integrate with.

  3. Managed services: While Lambda itself is flexible, using it with managed services like API Gateway or AppSync can simplify the implementation of specific API types (REST or GraphQL, respectively).

In conclusion, AWS Lambda doesn't have a specific API type, but rather serves as a versatile compute service that can be used to implement various API architectures, including REST, GraphQL, and even SOAP-to-REST conversions, depending on how it's integrated with other AWS services and configured by developers.

Does the AWS Lambda API have webhooks?

AWS Lambda API and Webhooks

The official AWS Lambda API itself does not directly provide webhooks. However, AWS offers several ways to integrate webhooks with Lambda functions and other AWS services:

  1. Amazon EventBridge with Lambda Function URLs

Amazon EventBridge now supports receiving events from third-party services like GitHub, Stripe, and Twilio using webhooks. This integration allows you to:

  • Create HTTP endpoints for your EventBridge event bus using AWS CloudFormation templates
  • Configure webhooks from supported SaaS providers to send events to these endpoints
  • Process the received events using Lambda functions

Types of Events You Can Subscribe To

The types of events you can subscribe to depend on the specific SaaS provider:

  • GitHub: All event types are supported
  • Twilio: Post-event webhooks are supported
  • Stripe: Event types supported by Stripe's webhook system (not explicitly mentioned in the search results, but included in the EventBridge integration)

Key Points to Consider

  1. Security: The webhooks are implemented using Lambda function URLs, which are secured at the Lambda application level by verifying the authentication signature sent by the third-party partner.

  2. Event Processing: Once events are received on the EventBridge event bus, you can use rules to filter events, apply input transformations, and route them to the appropriate targets (such as Lambda functions).

  3. Setup Process: AWS provides Quick Starts and CloudFormation templates to simplify the setup of these webhook integrations.

  4. Best Practices: When implementing webhooks, consider factors such as event generation, filtering, delivery, payload structure and size, security and authorization, subscription management, and monitoring.

Code Example

While the search results don't provide a specific code example, here's a high-level pseudocode representation of how you might handle a webhook event in a Lambda function:

import json def lambda_handler(event, context): # Parse the incoming webhook payload webhook_payload = json.loads(event['body']) # Extract relevant information from the payload event_type = webhook_payload['type'] event_data = webhook_payload['data'] # Process the event based on its type if event_type == 'payment.succeeded': process_payment_success(event_data) elif event_type == 'customer.created': process_new_customer(event_data) # Return a response return { 'statusCode': 200, 'body': json.dumps('Event processed successfully') } def process_payment_success(data): # Implement payment success logic pass def process_new_customer(data): # Implement new customer logic pass

Best Practices

  1. Implement proper authentication and verification for incoming webhooks.
  2. Handle payload sizes appropriately, considering service limits.
  3. Implement error handling and retries for webhook processing.
  4. Monitor webhook activity and set up alerting for any issues.
  5. Consider using EventBridge Pipes for advanced filtering and enrichment of webhook events.

In conclusion, while AWS Lambda doesn't have a native webhook system, you can effectively use it in combination with services like Amazon EventBridge to receive and process webhooks from various SaaS providers.

Rate Limits and other limitations

Here are the key API rate limits for AWS Lambda:

Invocation Requests

  • Synchronous invocations: Each execution environment instance can serve up to 10 requests per second [1].

  • Asynchronous invocations: Each execution environment instance can serve an unlimited number of requests [1].

  • For functions using provisioned concurrency: 10 x allocated provisioned concurrency [1].

API Requests

  • GetFunction API: 100 requests per second (cannot be increased) [1].

  • GetPolicy API: 15 requests per second (cannot be increased) [1].

  • Other control plane API requests (excluding invocations, GetFunction, and GetPolicy): 15 requests per second across all APIs (cannot be increased) [1].

Concurrency Scaling

  • For each function: 1,000 execution environments every 10 seconds [1].

Key Points to Consider

  • There is a concurrency limit for Lambda functions per Region [2].

  • You can configure reserved concurrency limits per Lambda function to control throughput based on different workloads [2].

  • API Gateway provides additional throttling options when exposing Lambda functions through APIs [2][3].

  • AWS throttling limits are applied across all accounts and clients in a Region and cannot be changed by customers [3].

Best Practices

  1. Use API Gateway throttling settings to prevent your API from being overwhelmed by too many requests [2].

  2. Consider enabling AWS WAF for additional protection and rate-based rules [2].

  3. Understand the relationship between concurrency limits, TPS (Transactions Per Second) limits, and burst limits to better interpret any throttling exceptions [4].

  4. For high-concurrency workloads, be aware of the burst limit to manage cold starts and ensure gradual scaling [4].

  5. Monitor your API usage and adjust throttling settings as needed to balance performance and cost.

By understanding and properly configuring these rate limits, you can ensure your Lambda functions and associated APIs perform optimally while preventing overload on your systems.

Latest API Version

Based on the search results provided, here are the key points regarding the most recent version of the AWS Lambda API:

Current Runtimes and Versions

  • Lambda supports multiple runtimes for different programming languages, including Node.js, Python, Ruby, .NET, and others.

  • The most recent runtimes mentioned in the search results include:

    • Node.js 18 (using Amazon Linux 2)
    • Python 3.9
    • Amazon Linux 2023 as a managed runtime and container base image

Upcoming Runtimes

  • Lambda plans to release new runtimes for:
    • Python 3.13 (target launch in November 2024)
    • Node.js 22 (target launch in November 2024)

Runtime Deprecation and Updates

  • Lambda provides managed runtimes for new language versions only when they reach the long-term support (LTS) phase.

  • Lambda sends email notifications and displays alerts on the AWS Health Dashboard at least 180 days before a runtime is deprecated.

  • Lambda keeps managed runtimes and their corresponding container base images up to date with patches and support for minor version releases.

Key Considerations

  • For new regions, Lambda will not support runtimes that are set to be deprecated within the next 6 months.

  • All supported Lambda runtimes support both x86_64 and arm64 architectures.

  • Lambda continues to support the Go programming language after deprecation of the Go 1.x runtime, but through a custom runtime on Amazon Linux 2.

It's important to note that the search results do not provide a specific version number for the AWS Lambda API itself. The information primarily focuses on the supported runtimes and their versions. To get the most up-to-date information on the AWS Lambda API version, it would be best to check the official AWS Lambda documentation or use the AWS CLI to query the current API version.

How to get a AWS Lambda developer account and API Keys?

To get a developer account for AWS Lambda and create an API integration, you'll need to follow these steps:

  1. Create an AWS account

The first step is to create an AWS account if you don't already have one. This will give you access to all AWS services, including Lambda and API Gateway.

Key points:

  • Go to the AWS homepage (aws.amazon.com) and click "Create an AWS Account"
  • You'll need to provide an email address, password, and billing information
  • The account creation process takes a few minutes to complete
  1. Set up IAM user (recommended)

While you can use your root AWS account, it's best practice to create an IAM user with appropriate permissions.

Key points:

  • Log into the AWS Management Console
  • Go to the IAM service
  • Create a new IAM user with programmatic access
  • Attach policies for Lambda and API Gateway access
  1. Create a Lambda function

Now you can create your Lambda function to serve as the backend for your API.

Key points:

  • Go to the Lambda console
  • Click "Create function"
  • Choose a runtime (e.g. Node.js, Python)
  • Write or upload your function code
  • Configure basic settings like memory and timeout
  1. Create an API in API Gateway

With your Lambda function created, you can set up the API integration.

Key points:

  • Go to the API Gateway console
  • Click "Create API"
  • Choose HTTP API or REST API type
  • Create resources and methods to define your API structure
  • Set up Lambda proxy integration with your function
  1. Deploy the API

The final step is to deploy your API to make it publicly accessible.

Key points:

  • Create a new stage (e.g. "prod")
  • Deploy the API to that stage
  • You'll receive an invoke URL to test your API

What can you do with the AWS Lambda API?

Based on the search results provided, here are the key data models you can interact with using the AWS Lambda API, along with what is possible for each:

Function Configuration

  • FunctionConfiguration: Represents the configuration of a Lambda function [2].
    • Allows you to retrieve and update function settings like runtime, memory, timeout, etc.
    • Enables you to view and modify function tags, environment variables, and VPC configuration.
    • Provides access to function metadata like ARN, last modified date, and code size.

Function Code

  • FunctionCode: Represents the code of a Lambda function [2].
    • Allows you to update the function code by providing a new deployment package.
    • Enables you to specify the code source (e.g., S3 bucket, inline code).
    • Provides options for specifying the runtime and handler for the function.

Event Source Mapping

  • EventSourceMapping: Represents a mapping between an event source and a Lambda function [2].
    • Allows you to create, update, and delete event source mappings.
    • Enables configuration of batch size, filtering criteria, and error handling options.
    • Provides status information about the mapping.

Layer

  • LayerVersionContentInput and LayerVersionContentOutput: Represent the content of a Lambda layer version [2].
    • Allow you to create and manage layer versions.
    • Enable specification of layer code and compatible runtimes.
    • Provide information about layer size and SHA256 hash.

Alias

  • AliasConfiguration: Represents a Lambda function alias [2].
    • Allows creation and management of function aliases.
    • Enables routing configuration for traffic shifting between function versions.
    • Provides information about the alias ARN and linked function version.

Version

  • FunctionVersion: Represents a specific version of a Lambda function [2].
    • Allows publishing of new function versions.
    • Provides access to version-specific configuration and code.
    • Enables listing and deletion of function versions.

Concurrency

  • Concurrency: Represents the concurrency settings for a Lambda function [2].
    • Allows configuration of reserved and provisioned concurrency.
    • Enables management of concurrency limits at the function level.
    • Provides information about current concurrency usage.

Permission

  • Permission: Represents a resource-based policy statement for a Lambda function [2].
    • Allows addition and removal of permissions for invoking the function.
    • Enables specification of principal, action, and conditions for the permission.
    • Provides management of cross-account access to the function.

These data models allow you to interact with various aspects of Lambda functions, from their configuration and code to event sources, layers, and permissions. Each model provides specific operations for managing and retrieving information about Lambda resources.