I had the idea that building an api gateway would be a fun project. This is still in early rapid development do not use yet unless you know what you're getting in to.

api requests get made to the gateway and it makes requests to services behind the gateway. Collects all those responses and then returns the compiled response to the client. Design restraint self imposed to try and not use a database.

• handle authorization

• handle rate limiting

• concurrently hit the backing services using a form of the go load balancer pattern

• configuration

  • need to have some way to configure so it knows where to look for things.

• url patterms

  • mygateway.foo.com/api1/* -> api1.someserver.com/*
    • passes through what ever http action was used.
  • the first / argument points to which app api to use.

• ability to mock end points

  • you make a call and the api sends back test/dummy data instead of reaching out backing services

• be able to run as a redundant pair by. local server will need config to define the other node(s). nodes will just send increment messages for rate limiting.

• ability to load new configs via its own api, and then reload those configs via its own REST api

• administrative rest endpoint that can be used to query for the current / configured / available apis this gateway is fronting

• rate limit, send back limit exceeded response.

  • X-Ratelimit-Used: Approximate number of requests used in this period
  • X-Ratelimit-Remaining: Approximate number of requests left to use
  • X-Ratelimit-Reset: Approximate number of seconds to end of period

• gateway daemon currently runs on port 8000. This will be configurable at runtime later.

• app config is a json file that looks like the below example. They are currently just being read out of the conf dir in the app root dir. This will change

to be clear is this the config for the applications that will be sitting behind the gateway. Not the gateway application it self.

GET /apps - List all applications that are behind this gateway
GET /apps/<app name> - List configuration information about specified app
POST /new - Post json payload to gateway to add a new backend application. See JSON example below

To send a normal query through the gateway send and HTTP request using whatever method your backend API expects /your_app_name/your/restful/parameters
A simple GET request could look like this http://localhost:8000/jsontest/posts/1

where localhost:8000 is the host and port of the gateway. jsontest is the name of the application in the gateway config. posts/1 are parameters that your API are expecting.

{
    "name": "userauth",
    "description": "service to authorize users of system",
    "authorize": true,
    "authKey": "thisismyauth",
    "authHeader": "X-Valet-Auth",
    "rateLimit": true,
    "limitValue": 2,
    "endpoints": [
        { "host": "auth.test.com", "path":"", "port":9050 },
        { "host": "auth.test.com", "path":"", "port":9051 }
    ]
}

Docker conatainer for this app can be found at https://hub.docker.com/r/jpweber/valet/