NginxでのWebSocketを含めたドメインでのリバースプロキシ

nginx-include-websocket-domain-based-reverse-proxy.conf

# For WebSocket
map $http_upgrade $connection_upgrade {
    default upgrade;
    ''      close;
}

server {
    server_name  sub.domain.tld;
    
    # For WebSocket
    proxy_set_header Upgrade $http_upgrade;
    proxy_set_header Connection $connection_upgrade;
    
    location / {
        proxy_pass https://localhost:3000/;
    }
}