webpack-dev-server proxy to docker container - docker

Question

I have 2 docker containers managed with docker-compose and can't seem to properly use webpack to proxy some request to the backend api.
docker-compose.yml :
version: '2'
services:
web:
build:
context: ./frontend
ports:
- "80:8080"
volumes:
- ./frontend:/16AGR/frontend:rw
links:
- back:back
back:
build:
context: ./backend
expose:
- "8080"
ports:
- "8081:8080"
volumes:
- ./backend:/16AGR/backend:rw
the service web is a simple react application served by a webpack-dev-server.
the service back is a node application.
I have no problem to access either app from my host :
$ curl localhost
> index.html
$ curl localhost:8081
> Hello World
I can also ping and curl the back service from the web container :
$ docker ps
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
73ebfef9b250 16agr_web "npm run start" 37 hours ago Up 13 seconds 0.0.0.0:80->8080/tcp 16agr_web_1
a421fc24f8d9 16agr_back "npm start" 37 hours ago Up 15 seconds 0.0.0.0:8081->8080/tcp 16agr_back_1
$ docker exec -it 73e bash
$ root#73ebfef9b250:/16AGR/frontend# curl back:8080
Hello world
However i have a problem with the proxy.
Webpack is started with
webpack-dev-server --display-reasons --display-error-details --history-api-fallback --progress --colors -d --hot --inline --host=0.0.0.0 --port 8080
and the config file is
frontend/webpack.config.js :
var webpack = require('webpack');
var config = module.exports = {
...
devServer: {
//redirect api calls to backend server
proxy: {
'/api': {
target: "back:8080",
secure: false
}
}
}
...
}
When i try to request /api/test with a link in my app for exemple i get a generic error, the link and google did not help much :(
[HPM] Error occurred while trying to proxy request /api/test from localhost to back:8080 (EINVAL) (https://nodejs.org/api/errors.html#errors_common_system_errors)
I suspect some weird thing because the proxy is on the container and the request is on localhost but I don't really have an idea to solve this.

Answer 1

I think I managed to tacle the problem.
Just had to change the webpack configuration with the following
devServer: {
//redirect api calls to backend server
proxy: {
'/api': {
target: {
host: "back",
protocol: 'http:',
port: 8080
},
ignorePath: true,
changeOrigin: true,
secure: false
}
}
}