API gateway

API gateway is the single entry point for all clients. Using API gateway comes with several benefits. Most notable are following:

• Client is unaware of the structure of the application,
• It's easier for client to determine location of service instances,
• Reduces the number of requests or roundtrips,...

How to define an API gateway

In the following example, we will define a service registry named EntryPoint:

api-gateway EntryPoint {
    // gateway will be registered within ServiceRegistry instance
    service_registry = ServiceRegistry

    deployment {
        version="0.0.1"
        port=9095
        url="http://localhost"
        host=container
    }

    communication_style=rpc

    gateway-for {
        User as /api/u
        Order as /api/o
        ...
    }
}

API gateway has following attributes:

• name (mandatory) - name of the API gateway.
• service_registry (optional) - reference to a service registry where the service will be registered,
• deployment (optional) - tells how gateway will be deployed (more info can be found here),
• gateway-for (mandatory) - Maps service instance to URL. By using this URL, clients can reach corresponding the service.