PDFKit (wkhtmltopdf) Broken Pipe, OS X and Rails 3

Question

I'm using PDFKit (which uses wkhtmltopdf) in an attempt to render a view as pdf within a Rails 3 app.

PDFKit renders with Errno::EPIPE (Broken pipe) pointing to send_data(kit.to_pdf, :filename => "generated.pdf", :type => 'application/pdf') in my controller show action:

# Controller
def show
  respond_to do |format|
    format.html { render }
    format.pdf do
      html = render_to_string(:layout => false , :action => "show.html.haml")
      kit = PDFKit.new(html)
      send_data(kit.to_pdf, :filename => "invoice.pdf", :type => 'application/pdf')
      return # to avoid double render call
    end
  end
end

# Gemfile
...
gem 'pdfkit'
gem 'wkhtmltopdf'
...

I know wkhtmltopdf is not the source of this error as wkhtmltopdf public/404.html tmp/404.pdf from within Rails.root works as expected.

I'm using an example from jonathanspies.com after using the middleware failed in the same manner.

# config/application.rb
require 'pdfkit'
config.middleware.use PDFKit::Middleware

After trying it in a fresh Rails 3 app, I get the following error:

command failed: "~/.rvm/gems/ree-1.8.7-2011.01@blog/bin/wkhtmltopdf" "--page-size" "Letter" "--margin-right" "0.75in" "--margin-top" "0.75in" "--margin-bottom" "0.75in" "--encoding" "UTF-8" "--margin-left" "0.75in" "--quiet" "-" "-"

Running the command manually and usage screen is displayed, looking at the --quiet option it is easy to see its supposed to be --quit

Change /lib/pdfkit/pdfkit.rb:35 to the following and everything works as expected (with middleware too).

args << '--quit'

So, once again, I've solved my problem in the act of writing the question to get help (always pays to include detail). I submitted a pull request which corrects the spelling mistake (always a silly mistake which gets unnoticed). Hope nobody minds me posting anyways.

Answer 1

Regarding changing the quiet argument to quit.

This change is only valid if you are using the wkhtmltopdf gem which uses a very old version of the wkhtmltopdf binary.

With the wkhtmltopdf gem

10:32:15 wkhtml >     wkhtmltopdf --version
wkhtmltopdf 0.8.3 using wkhtmltopdf patched qt
Copyright (C) 2008,2009 Jakob Truelsen,
License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.

Written by Jakob Truelsen
Patches by Mário Silva and Emmanuel Bouthenot

10:32:16 wkhtml >     wkhtmltopdf --help | grep quit
  -q, --quit                      Be less verbose.
10:32:16 wkhtml >     wkhtmltopdf --help | grep quite
10:32:19 wkhtml > 

With the latest binary I have installed

10:33:40 tmp > wkhtmltopdf --version
Name:
  wkhtmltopdf 0.9.9

License:
  Copyright (C) 2008,2009 Wkhtmltopdf Authors.



  License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>.
  This is free software: you are free to change and redistribute it. There is NO
  WARRANTY, to the extent permitted by law.

Authors:
  Written by Jakob Truelsen. Patches by Mário Silva, Benoit Garret and Emmanuel
  Bouthenot.

10:33:50 tmp > wkhtmltopdf --help | grep quit
10:34:02 tmp > wkhtmltopdf --help | grep quiet
  -q, --quiet                         Be less verbose
10:34:07 tmp > 

The spelling mistake exists in the old binary that comes with the wkhtmltopdf gem. I would suggest you monkey patch pdfkit with an initialize or something based on if you included the wkhtmltopdf gem or not.

I would also accept a pull request that made pdfkit aware of the version of wkthtmltopdf it was running against and conditionally switched that argument.

Answer 2

Change /lib/pdfkit/pdfkit.rb:35 to the following and everything works as expected (with middleware too).

args << '--quit'