A reproductible EPROTO error with selenium-webdriver in javascript

docker-compose.yml

version: '2'

services:
  nginx:
    build: .
    restart: always
    ports:
      - 80:80

Dockerfle

FROM nginx:alpine

COPY nginx.conf /etc/nginx/nginx.conf

gistfile1.txt

const webdriver = require("selenium-webdriver");

let driver = new webdriver.Builder()
  .forBrowser("firefox")
  .usingServer("https://a-real-selenium-grid/wd/hub")
  .usingWebDriverProxy("http://localhost:80")
  .build();

driver.quit();

nginx.conf

worker_processes 1;

events { worker_connections 1024; }

http {
    sendfile on;

    server {
        listen 80;
        server_name localhost;

        location / {
            proxy_pass         https://a-real-selenium-grid;
            proxy_redirect     off;
            proxy_set_header   Host $host;
            proxy_set_header   X-Real-IP $remote_addr;
            proxy_set_header   X-Forwarded-For $proxy_add_x_forwarded_for;
            proxy_set_header   X-Forwarded-Host $server_name;
        }
    }
}