when click the print to PDF on the invoice page. The PDF conversion does not take place and throws the 504 Gateway Time-out.
2019/03/22 14:41:08 [error] 483#0: *556 upstream timed out (110: Connection timed out) while reading response header from upstream, client: x.x.x.x, server: site1.local, request: “GET /api/method/frappe.utils.print_format.download_pdf?doctype=Sales%20Order&name=SO3-0461&format=Standard&no_letterhead=1&_lang=en-US HTTP/1.1”, upstream: “http://127.0.0.1:8000/api/method/frappe.utils.print_format.download_pdf?doctype=Sales%20Order&name=SO3-0461&format=Standard&no_letterhead=1&_lang=en-US”, host: “erp.xxxxxxx.com”, referrer: “http://erp.xxxxxxxx.com/desk”