by Kubernetes has become a standard platform for container orchestration, providing powerful capabilities for managing and scaling containerized applications. As the adoption of microservices architecture has grown, so has the need for advanced networking features. Kubernetes offers several networking APIs, including the Ingress API and the Gateway API. In this article, we will explore the differences between these two APIs, and when to use each one.
What is the Ingress API?
The Ingress API is a Kubernetes resource that provides a way to route external traffic to internal services in a Kubernetes cluster. Acting as a reverse proxy and load balancer, Ingress enables the exposure of multiple services via a single IP address and domain name. Ingress rules direct traffic based on the host name, path, or other HTTP headers.
Ingress operates as a Layer 7 (application layer) load balancer. This allows it to route traffic based on the content of the request, making it ideal for routing traffic to HTTP/HTTPS services. It is essential to note that Ingress doesn’t support protocols other than HTTP/HTTPS.
What is the Gateway API?
The Gateway API is a Kubernetes resource that provides a way to configure and manage advanced networking features such as traffic shaping, security, and observability. The Gateway API acts as a Layer 7 (application layer) load balancer and as a Layer 4 (transport layer) load balancer. As a result, it can route traffic based on IP addresses, ports, or protocols, which makes it suitable for routing traffic to non-HTTP/HTTPS services, such as TCP or UDP.
The Gateway API provides several advanced features such as traffic splitting, traffic mirroring, and traffic shifting, which can be used to implement canary deployments, blue-green deployments, and A/B testing.
Differences between Ingress and Gateway
One significant difference between Ingress and Gateway is the layer of the network stack they operate. Ingress is a Layer 7 load balancer that routes traffic based on the content of the request. Gateway, on the other hand, is a Layer 7 and Layer 4 load balancer that can route traffic based on IP addresses, ports, or protocols.
Another difference is the level of complexity they offer. Ingress is a simple API that is easy to set up and use, providing basic routing capabilities that support only HTTP/HTTPS traffic. Gateway, on the other hand, is a more advanced API that offers a wide range of networking features, including traffic shaping, security, and observability. It supports a variety of protocols and is more suitable for complex deployments.
Finally, Ingress requires the use of an Ingress controller, such as Nginx or Traefik, which handles the actual routing of traffic. Gateway, on the other hand, is a standalone resource that does not require an external controller.
When to use Ingress or Gateway
In general, Ingress should be used when routing HTTP/HTTPS traffic, and Gateway should be used when routing traffic to non-HTTP/HTTPS services, such as TCP or UDP. If advanced networking features, such as traffic shaping, security, or observability, are required, Gateway should be used. If only basic routing capabilities are needed, Ingress will suffice.
In some cases, both Ingress and Gateway can be used together. For example, Ingress can be used to route HTTP/HTTPS traffic to services, and Gateway can be used to route non-HTTP/HTTPS traffic.
Conclusion
Kubernetes provides two networking APIs, Ingress and Gateway, to manage and route traffic to containerized applications. Ingress is a Layer 7 load balancer that is suitable for HTTP/HTTPS traffic, while Gateway is a more advanced API that provides a broader range of networking features, including support for protocols beyond HTTP/HTTPS. It’s important to evaluate the specific networking requirements of your application to determine which API is the best fit. By leveraging the right API, you can ensure that your Kubernetes network is optimized for the performance, security, and scalability needs of your application.