Use with Heroku

Instructions

[Update] You can use wkhtmltopdf-heroku gem for Heroku. You do not need to configure anything, just ensure config.wkhtmltopdf is not being set for Heroku.

First you need to use the heroku-buildpack-multi:

heroku buildpacks:set https://github.com/heroku/heroku-buildpack-multi.git

Then create a .buildpacks file in your repo root containing:

https://github.com/heroku/heroku-buildpack-apt
https://github.com/heroku/heroku-buildpack-ruby
https://github.com/a2ikm/heroku-buildpack-libjpeg62

Use apt-get to install wkhtmltopdf. Create an Aptfile in your repository root with content:

https://wkhtmltopdf.org/downloads.html

And finally instruct PDFKit the location of wkhtmltopdf on Heroku at config/initializers/pdfkit.rb:

PDFKit.configure do |config|
  if File.executable? '/app/.apt/usr/local/bin/wkhtmltopdf'
    config.wkhtmltopdf = '/app/.apt/usr/local/bin/wkhtmltopdf'
  end
end

libjpeg62 is not installed on cedar-14 (why is it needed for pdfkit?). You can install it with .buildpacks by adding https://github.com/a2ikm/heroku-buildpack-libjpeg62.git. It may also work by adding libjpeg62 libjpeg62-dev to Aptfile (but haven't seen any failures without it installed at all, so don't know if this works).