PDF generation fails: wkhtmltopdf ConnectionRefusedError

[redolencetech]

Information about bug

There are many issues raised in the past about generating PDFs with wkhtmltopdf, I have been playing around with different troubleshooting options - and I believe I have conceptually figured out the solution but don't know enough Python or about ERPNext to resolve it:

Changing host_name in sites/[sitename]/site_config.json from my actual host/domain name to "https://127.0.0.1:443" or "http://127.0.0.1:80" allows wkhtmltopdf to work, but it then breaks OAuth for logging in via Office365, links in the footer of emails to open the documents online, etc. - basically, anywhere the host name value is factored in.

I believe we need to dynamically replace the hostname being passed to wkhtmltopdf from the PDF button from the actual hostname to the localhost

Sources:
https://discuss.frappe.io/t/pdf-printing-issues/97832/3
https://discuss.frappe.io/t/wkhtmltopdf-error-creating-pdf/101926/8
https://discuss.frappe.io/t/oserror-wkhtmltopdf-reported-an-error-exit-with-code-1-due-to-network-error-sslhandshakefailederror/96029/1

Follow-on issue - this issue makes it impossible to send emails from the system as wkhtmltopdf doesn't let them go through

I'm using the Bitnami VM for ERPNext

Module

accounts, stock, buying, selling, ecommerce, manufacturing, HR, projects, support, CRM, assets, integrations, quality, regional, portal, agriculture, education, non-profit, other

Version

Akwad UI Fixes: v1.0.4
Desk Navbar Extended: v0.0.1
ERPNext: v14.28.1
ERPNext OCR: v1.0.1
Frappe Framework: v14.40.1
Frappe M365: v0.0.1
Frappe Insights: v0.6.2
Microsoft Integration: v0.0.1
One Compliance: v0.0.1
Payments: v0.0.1
SCS Sales-Purchase: v0.0.1
Simple Stock: v0.0.1
Wiki: v2.0.0

Installation method

manual install

Relevant log output / Stack trace / Full Error Message.

Traceback (most recent call last):
  File "apps/frappe/frappe/app.py", line 66, in application
    response = frappe.api.handle()
  File "apps/frappe/frappe/api.py", line 54, in handle
    return frappe.handler.handle()
  File "apps/frappe/frappe/handler.py", line 47, in handle
    data = execute_cmd(cmd)
  File "apps/frappe/frappe/handler.py", line 85, in execute_cmd
    return frappe.call(method, **frappe.form_dict)
  File "apps/frappe/frappe/__init__.py", line 1608, in call
    return fn(*args, **newargs)
  File "apps/frappe/frappe/utils/print_format.py", line 133, in download_pdf
    pdf_file = frappe.get_print(
  File "apps/frappe/frappe/__init__.py", line 2041, in get_print
    return get_pdf(html, options=pdf_options, output=output)
  File "apps/frappe/frappe/utils/pdf.py", line 38, in get_pdf
    filedata = pdfkit.from_string(html, options=options or {}, verbose=True)
  File "env/lib/python3.10/site-packages/pdfkit/api.py", line 75, in from_string
    return r.to_pdf(output_path)
  File "env/lib/python3.10/site-packages/pdfkit/pdfkit.py", line 202, in to_pdf
  File "env/lib/python3.10/site-packages/pdfkit/pdfkit.py", line 156, in handle_error
OSError: wkhtmltopdf reported an error:
Exit with code 1 due to network error: ConnectionRefusedError

[James3UK]

see also:
#35155
#35155 (comment)

wkhtmltopdf has been abandoned the last year and the repository is now archived.
Its author recommends WeasyPrint.

When setting to 127.0.0.1 I get the content not found error as here:
frappe/frappe#19701

[ankush]

Duplicate frappe/frappe#23958

possible fix: host_name should be public facing host name and not local IP.

[pgandert1963]

I have the same issue.
Interactively the PDF generation is working very well.
But in the context of sending email the wkhtmltopdf is throwing a ConnectionRefusedError.
Also setting the host_name to the public visible url brings no result.
When setting the host_name to 127.0.0.1 then sending the mail with attachment is working and no error is thrown. But with host_name 127.0.0.1 the interactive Rendering of PDF is broken.
This is in my opinion a showstopper, because there is no remedy for this.
The backgroundscript should work on localhost, while the frontend can use the public visible url.

SOLUTION. When setting the host_name ONLY the url must be set. Never include http:// or https://.
Example: www.mydomain.tld instead of https://www.mydomain.tld
Now both usecases are working.