server {
  listen 80;
  server_name _;

  root /usr/share/nginx/html;
  index index.html;

  # Resolve the backend hostname at request time (via Docker's embedded DNS)
  # instead of once at startup, so a recreated backend container is picked
  # up without needing to restart/reload this nginx.
  resolver 127.0.0.11 valid=30s;

  location /api/ {
    set $backend_upstream presencia-backend;
    # $request_uri (the raw, un-normalized original URI) must be appended
    # explicitly: when the proxy_pass target is built from a variable,
    # nginx does NOT replace the matched location prefix with the rest of
    # the request URI like it does for a static proxy_pass value — it
    # would otherwise always forward the literal "/api/" with nothing
    # appended, regardless of the actual path requested.
    proxy_pass http://$backend_upstream:4790$request_uri;
    proxy_http_version 1.1;
    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-Proto $scheme;
  }

  location / {
    try_files $uri $uri/ /index.html;
  }
}