If you’re into microservices and APIs, you might have come across the term “Hermes Gateway”. But what exactly is it, and why should you care?
What is Hermes Gateway?
In simple terms, Hermes Gateway is an open-source API gateway that acts as a middleware layer between your microservices and the outside world. It’s built using Node.js and Express.js, and provides features such as rate limiting, caching, authentication, request/response logging, and more.
One of the key benefits of using an API gateway like Hermes is that it allows you to decouple your microservices from the client applications that consume them. Instead of having each client talk directly to each microservice (which can lead to tight coupling and complex network topologies), the API gateway acts as a single entry point for all requests.
This reduces complexity by consolidating cross-cutting concerns like security and rate limiting into a single place. It also makes it easier to version your APIs by allowing you to introduce breaking changes in a controlled manner.
How does Hermes Gateway work?
Hermes Gateway sits between your client applications (e.g. web or mobile apps) and your backend microservices.
When a request comes in from a client, Hermes intercepts it and applies any necessary middleware (e. authentication checks or rate limiting).
Once the request has been processed by the middleware chain, Hermes forwards it on to the appropriate microservice based on the URL path or other routing rules.
When the microservice responds with a result, Hermes intercepts it again and applies any necessary post-processing (e. adding headers or modifying response content). Finally, Hermes sends the response back to the client application.
By using an API gateway like Hermes, you can simplify your overall architecture while still allowing individual microservices to evolve independently over time.
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Features of Hermes Gateway
Hermes Gateway provides a number of useful features out of the box, including:
- Rate limiting: You can configure Hermes to limit the number of requests that a client can make in a given time period.
- Caching: Hermes can cache responses from your microservices to improve performance and reduce load on your backend.
- Authentication: You can use Hermes to enforce authentication and authorization rules for incoming requests.
- Request/response logging: Hermes can log details about incoming requests and outgoing responses for debugging purposes.
- API versioning: You can use Hermes to version your APIs by routing different versions of endpoints to different microservices.
In addition to these built-in features, Hermes Gateway is highly extensible. You can write custom middleware functions to add your own functionality, or even replace the default middleware stack entirely.
The benefits of using an API gateway like Hermes
Using an API gateway like Hermes has several benefits, including:
- Simpler network topology: By consolidating cross-cutting concerns into a single place, you can simplify the overall architecture of your system.
- Better security: By enforcing authentication and authorization rules at the gateway level, you can reduce the attack surface of your backend microservices.
- Easier versioning: By introducing breaking changes at the gateway level (e. by routing new API versions to new microservices), you can avoid having to coordinate changes across multiple client applications.
- Better observability: By logging details about incoming requests and outgoing responses, you can gain better insight into how your system is behaving.
Conclusion
Hermes Gateway is a powerful open-source API gateway that can help you simplify the architecture of your microservices-based system. By using Hermes to consolidate cross-cutting concerns like security and rate limiting, you can make it easier to evolve your system over time and reduce the complexity of your network topology.