ReverseProxyDemo

The purpose of this repo is to demonstrate a problem with a NestJS middlware combined with the npm package http-proxy-middlware. There's a corresponding StackOverflow post referring to this repo.

Get apps up and running

1. Clone the repo
2. Run npm install
3. Fire up the Todos API via ng serve todos-api. Run curl http://localhost:8090/api and you should receive a 200 OK response with an array of todos.
4. Fire up the API Gateway via ng serve api-gateway. Run curl http://localhost:8080/api and you should receive a 200 OK response with a JSON response {"ok":true}.

Re-produce the issue

The following requests are sent to the API Gateway on port 8080 which serves as kind of a reverse proxy for the Todos API which runs on port 8090.

• Requests made to http://localhost:8080/api/v1/... are reverse-proxied through a global functional middleware which is setup in main.ts.
• Requests made to http://localhost:8080/api/v2/... are reverse-proxied through a NestJS Middlware which is setup in reverse-proxy.middleware.ts and registered in app.module.ts.

In the following requests you'll see that the GET requests are proxied successfully through both kinds of middlwares. The PUT request, though, is only proxied successfully throug the global functional middlware. Proxying through the Nest JS Middeware fails, the client never receives a response (it's kinda "hanging").

1. Run curl http://localhost:8080/api/v1/todos-api and you should receive the array of todos.
2. Run curl http://localhost:8080/api/v2/todos-api and you should also receive the array of todos.
3. Run curl -X PUT -H "Content-Type: application/json" -d "{\"id\": 1, \"userId\": 1, \"title\": \"delectus aut autem - v1\", \"completed\": true}" http://localhost:8080/api/v1/todos-api/1 and you should receive a 200 OK and the todo should have been updated successfully.
4. Run curl -X PUT -H "Content-Type: application/json" -d "{\"id\": 1, \"userId\": 1, \"title\": \"delectus aut autem - v2\", \"completed\": true}" http://localhost:8080/api/v2/todos-api/1 and you will never receive a response, the request just keeps "hanging".