API Gateways for Serverless: Top 5 Solutions & Tips for Success

What Is an API Gateway? 

An API gateway is a server that acts as an intermediary between clients and backend services, providing a single entry point for managing, securing, and routing API requests. It helps streamline the communication between multiple microservices, allowing developers to create, publish, and monitor APIs in a unified manner. 

Key features of API gateways include request authentication, rate limiting, caching, logging, and transforming requests and responses. By abstracting the complexity of the underlying services, API gateways simplify API management, enhance security, and improve scalability and performance of distributed applications. 

We should mention that a growing number of APIs support the industry standard OpenAPI specification. This makes it easier to manage APIs via API Gateways, and enables granular observability by formally defining API functionality.

This is part of a series of articles about serverless monitoring

Benefits of API Gateway Frameworks for Serverless Applications 

An API Gateway plays a critical role in serverless applications by providing a single entry point for managing, securing, and routing API requests to serverless functions or other backend services. Using an API Gateway for serverless applications offers several advantages:

• Simplified API management: An API gateway centralizes the management of multiple serverless functions or services. It provides a single place to create, publish, and monitor APIs, making it easier to manage and maintain the entire application.
• Request routing: The gateway is responsible for routing incoming API requests to the appropriate serverless functions or backend services based on predefined rules or paths. This ensures that requests are directed to the correct resources and helps maintain a clean separation of concerns.
• Security: API gateways provide built-in security features such as authentication, authorization, and rate limiting to protect your serverless functions from unauthorized access and potential attacks. By offloading security concerns to the API Gateway, developers can focus on implementing application-specific logic.
• Scaling: It can handle a large number of incoming requests, automatically scaling to accommodate fluctuations in demand. This ensures that your serverless functions can efficiently handle varying levels of traffic without manual intervention.
• Caching: Many API gateways support caching, which can store the results of API calls temporarily. This reduces the number of calls made to the serverless functions, thereby improving performance and reducing the overall cost of running the application.
• Monitoring and analytics: API gateways often include monitoring and analytics capabilities, providing insights into API usage, performance, and potential issues. This enables you to optimize your serverless application and identify areas for improvement.
• Custom domain and SSL/TLS support: API gateways allow you to configure custom domain names and SSL/TLS certificates, ensuring that your serverless application’s API is secure and accessible via a user-friendly URL.

Learn more in our detailed guide to serverless framework (coming soon)

Top 5 Serverless API Gateway Solutions  

1. Amazon API Gateway

Amazon API Gateway is AWS’ fully managed service that allows developers to easily create, publish, secure, maintain, and monitor APIs at various scale. It allows the creation of RESTful and WebSocket APIs that can be integrated with AWS services, including AWS Lambda for serverless computing. By utilizing API Gateway with Lambda, developers can build serverless applications that automatically scale with the number of requests, without provisioning or managing servers.

Key features of Amazon API Gateway include caching, logging, security (using AWS Identity and Access Management or custom authorizers), request/response transformation, and throttling. The pay-as-you-go pricing model ensures cost-effectiveness for varying workloads.

2. Azure API Management

Azure API Management is a fully managed service by Microsoft that enables developers to create, publish, and manage APIs in a secure and scalable manner. It can be integrated with Azure Functions, Microsoft’s serverless computing service, providing a seamless way to build serverless applications.

Key features include API versioning, caching, analytics, custom domain support, security (using Azure Active Directory, OAuth, or OpenID Connect), request/response transformation, and rate limiting. The platform also supports hybrid and multi-cloud environments, offering flexibility for various deployment scenarios.

3. Google Cloud API Gateway

Google Cloud API Gateway is a managed service that helps developers create, secure, and monitor APIs for their serverless workloads running on Google Cloud. It can be easily integrated with Google Cloud Functions and Cloud Run, enabling serverless applications to scale automatically with demand.

Key features include API versioning, security (using Firebase Authentication, Google Identities, or custom authentication), logging and monitoring (integrated with Google Cloud’s operations suite), request/response transformation, and rate limiting. The service supports gRPC, REST, and GraphQL APIs, offering flexibility for different use cases.

4. Kong

Kong API Gateway is an open-source, scalable, and high-performance API management solution that can be deployed on-premises or in the cloud. It can be integrated with serverless platforms like AWS Lambda, Azure Functions, and Google Cloud Functions, enabling developers to build serverless applications while benefiting from Kong’s extensive plugin ecosystem.

Key features include security (using OAuth, JWT, or custom authentication), rate limiting, caching, logging, request/response transformation, and an extensible plugin architecture. Kong also offers an Enterprise version with additional features, such as advanced security, analytics, and multi-zone deployments.

5. Tyk

Tyk Gateway is an open-source, lightweight, and high-performance API gateway that can be deployed on-premises, in the cloud, or in hybrid environments. It supports integration with serverless platforms like AWS Lambda, enabling developers to build serverless applications while leveraging Tyk’s API management capabilities.

Key features include API versioning, security (using OAuth, JWT, or custom authentication), rate limiting, caching, logging, request/response transformation, and an extensible plugin architecture. Tyk also offers a Pro version with additional features, such as API analytics, developer portal, and multi-data center support.

Best Practices for Implementing API Gateway for Serverless Applications 

Implementing API Gateway best practices for serverless applications ensures better performance, security, and maintainability. Here are some best practices to consider when using an API Gateway for serverless applications:

• Use a single API Gateway: Centralize the management of your serverless functions by using a single API Gateway to route requests to multiple services or functions. This simplifies API management, reduces maintenance overhead, and allows for consistent security and monitoring across your serverless application.
• Implement authentication and authorization: Use built-in or custom authentication and authorization mechanisms to protect your serverless functions from unauthorized access. Common authentication methods include API keys, OAuth 2.0, and JSON Web Tokens (JWT).
• Rate limiting and throttling: Implement rate limiting and throttling policies to protect your serverless functions from abuse or denial of service (DoS) attacks. This also helps to control costs and ensure fair usage of resources among users.
• Use caching: Enable caching at the API Gateway level to reduce the number of requests made to your serverless functions, improve response times, and reduce costs. Cache frequently accessed data and use appropriate cache invalidation strategies to maintain data consistency.
• Logging and monitoring: Enable logging and monitoring features in your API Gateway to gain insights into API usage, performance, and potential issues. Use these insights to optimize your serverless application and identify areas for improvement.
• Implement a versioning strategy: Use a versioning strategy for your APIs to allow for changes and updates without breaking existing clients. This enables you to deploy new features and improvements without affecting the application’s stability.
• Optimize performance: Use techniques such as pagination, response compression, and proper HTTP status codes to improve the performance and user experience of your serverless APIs. Minimize the payload size and use efficient data formats like JSON or Protocol Buffers when applicable.
• Design APIs with scalability in mind: Ensure that your serverless functions and APIs are designed to handle a varying load of traffic. Use auto scaling capabilities provided by your serverless platform and API Gateway to handle traffic spikes and ensure consistent performance.
• Use SDK as a service: Building SDKs that support multiple programming languages is very time consuming. SDK as a service is an emerging pattern that lets you support the automatic generation of SDKs for multiple programming languages and platforms. Read more in our blog post about SDK as a service.

By following these best practices, you can build robust, secure, and efficient serverless applications using an API Gateway. This will help you maintain and manage your serverless application more effectively while ensuring a better user experience.

Serverless API Gateway with Lumigo

API Gateways provides developers with a convenient tool to create serverless applications with a unified API interface. As the connective tissue between microservices, it’s critical to have proper observability of your APIs so issues can be found and fixed quickly. Lumigo is an observability and troubleshooting platform that offers views specific to API Gateway with key metrics to help you monitor and debug Lambdas triggered by an http. 

Learn more about Lumigo