What is an API gateway?
An API gateway is a piece of software infrastructure that sits between the outside world (clients or end users) and the backend services in your datacenter or cloud. APIs (application programming interfaces) are a set of protocols and functions that define how application services can communicate without having to know how they are implemented. This interface can be used to integrate application services to each other and can simplify development cycles. An API gateway functions to accept incoming requests (traffic), routes them to the appropriate backend service based on a set of rules and policies defined by the organization, and then returns the appropriate result to the end user or client.
API Gateway vs. API Management
An API gateway is part of the overall API management system and although it is not new, the role of the API gateway is going through an identity crisis as we adopt newer platforms like Kubernetes, containers, and public cloud. API management is a broader discipline that includes the process of creating, publishing, managing, reporting, and sometimes monetizing APIs.
Traditional API gateways were not designed for highly dynamic environments like Kubernetes. They require additional infrastructure to be made highly-available and production ready. Additionally traditional API gateways are often deployed in a centralized manner that conflicts with the distributed nature of modern applications.
Depending on the needs of your organization and application portfolio, you may need both API gateway and management tools. You need to consider if their existing API gateway can support the needs of the new applications and infrastructure in addition to your existing services.
What can you do with an Envoy-based API gateway?
The API gateway acts to intercept all your incoming traffic and route it to the appropriate backend service in compliance with the rules and policies implemented by your administrator.
Architecturally, API gateways consist of a data plane and a control plane. The data plane is where the traffic is flowing from your external clients and users through the proxies to the backend services. This is often referred to as north-south traffic. The control plane is where your configuration and policies are defined and maintained. These configurations are pushed to the proxies to adjust the flow of traffic or to add security checks like authentication. With the evolution to cloud-native architectures, technology like the open source Envoy Proxy has emerged to enable high performance application communication for distributed systems. Envoy has become the proxy of choice at the edge as the sidecar to service mesh infrastructure.
As you adopt microservices and Kubernetes application patterns, the role of the API gateway becomes critical to ensuring a good end user experience in accessing applications that are now made up of potentially hundreds of different backend services. API gateways are not limited to microservices and can support a range of application workloads including monolithic applications and serverless functions. APIs are the interface by which your application services communicate and the gateway is the control point for routing, shaping, and securing that traffic. As the API gateway intercepts the incoming request, security rules can be applied to inspect the request, authenticate the client or end user, and to rate limit the request to protect the backend service from exploit or failure. Additionally the API gateway can route and shape traffic to support use cases like canary deployments and traffic shadowing to ensure safer application deployments and to maintain your end user experience.
Modernizing legacy monolithic applications are challenging time consuming and expensive. Existing approaches present inflexible options that leave IT teams with a difficult task of trying to balance supporting the existing business while delivering new value to customers.
- Complete rewrites of legacy applications are expensive and time consuming
- Abandoning legacy applications for new green-field application development is not realistic
Take back control of your IT transformation with Gloo Edge, a modern API gateway that extends the value of your existing IT investments while enabling you to integrate new technologies at the the pace of your business, without disruption.
- Connect legacy monoliths, microservices, and serverless functions together into a hybrid application
- Add new features as microservices and serverless to existing applications