map $http_upgrade $connection_upgrade {
    default upgrade;
    'websocket' upgrade;
}
server {
    listen       80;
    server_name  localhost;
    client_max_body_size 100M;

    location /api/ {
            proxy_set_header Upgrade $http_upgrade;
            proxy_set_header Connection $connection_upgrade;
            proxy_pass   http://localhost:8443;
    }
}