nginx.conf

# Nginx template: variables are substituted at container start (envsubst)
# Variables expected:
#   - ${NGINX_SERVER_PORT} (default: 8081): port nginx will listen on inside the container
#   - ${NGINX_BACKEND_URL} (default: http://host.docker.internal:8080/): backend to proxy /api/ to (include trailing slash)
server {
    listen       ${NGINX_SERVER_PORT};
    server_name  localhost;

    location / {
        root   /usr/share/nginx/html;
        index  index.html;
        try_files $uri /index.html;
    }

    location /api/ {
        proxy_pass ${NGINX_BACKEND_URL};
        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;
        proxy_set_header Upgrade $http_upgrade;
        proxy_set_header Connection $http_connection;
    }
}