lumi.conf

server {
    listen 80;
    server_name api.domain.com;
    return 301 https://$server_name$request_uri;
}

server {
    listen 443;
    server_name api.domain.com;
    ssl on;
    ssl_certificate /etc/nginx/ssl/cert/bundle.crt;
    ssl_certificate_key /etc/nginx/ssl/key/key.key;
    location / {
        proxy_set_header Host $http_host;
        proxy_pass http://127.0.0.1:8001/;
        proxy_redirect off;
    }
}

map $http_upgrade $connection_upgrade {
        default upgrade;
        ''      close;
}

server {
    listen 80;
    server_name sockets.domain.com;
    return 301 https://$server_name$request_uri;
}

server {
    listen 443;
    server_name sockets.domain.com;
    ssl on;
    ssl_certificate /etc/nginx/ssl/cert/bundle.crt;
    ssl_certificate_key /etc/nginx/ssl/key/key.key;
    location / {
        proxy_pass http://127.0.0.1:4000;
        proxy_http_version 1.1;
        proxy_set_header Upgrade $http_upgrade;
        proxy_set_header Connection $connection_upgrade;
        proxy_read_timeout 86400;
    }
}

nginx.conf

user www-data;
worker_processes 4;
pid /run/nginx.pid;

events {
	worker_connections 768;
	# multi_accept on;
}

http {

	##
	# Basic Settings
	##

	sendfile on;
	tcp_nopush on;
	tcp_nodelay on;
	keepalive_timeout 65;
	types_hash_max_size 2048;
	# server_tokens off;

	client_max_body_size 4m;

	server_names_hash_bucket_size 64;
	# server_name_in_redirect off;

	# Fastcgi
	fastcgi_buffers 16 16k;
	fastcgi_buffer_size 32k;

	# Proxy
	proxy_buffer_size   128k;
	proxy_buffers   8 256k;
	proxy_busy_buffers_size   256k;

        # Header configs
        client_header_buffer_size 32k;
        large_client_header_buffers 8 32k;

	include /etc/nginx/mime.types;
	default_type application/octet-stream;

	##
	# Logging Settings
	##

	access_log /var/log/nginx/access.log;
	error_log /var/log/nginx/error.log;

	##
	# Gzip Settings
	##

	gzip on;
	gzip_disable "msie6";

	# gzip_vary on;
	# gzip_proxied any;
	# gzip_comp_level 6;
	# gzip_buffers 16 8k;
	# gzip_http_version 1.1;
	# gzip_types text/plain text/css application/json application/x-javascript text/xml application/xml application/xml+rss text/javascript;

	##
	# nginx-naxsi config
	##
	# Uncomment it if you installed nginx-naxsi
	##

	#include /etc/nginx/naxsi_core.rules;

	##
	# nginx-passenger config
	##
	# Uncomment it if you installed nginx-passenger
	##

	#passenger_root /usr;
	#passenger_ruby /usr/bin/ruby;

	##
	# Virtual Host Configs
	##

	include /etc/nginx/conf.d/*.conf;
	include /etc/nginx/sites-enabled/*;
}