SmartTrackers fork

In this custom fork we only add the binaries for the platforms we need. For Heroku and CircleCI this is Ubuntu 22 and for all the local development machines this is MacOS. This reduces the slug size on Heroku considerably.

Installation and usage

Install in your Gemfile as usual

gem 'wkhtmltopdf-binary'

In many environments, this is all you need to do. This gem installs a binary stub that tries to determine which wkhtmltopdf binary will work on your system, and point to the packaged binary that most closely matches.

In some environments, invoking this binary will result in an error, saying the needed permissions are not available. This is because wkhtmltopdf-binary ships with gzipped binaries for many platforms, and then picks the appropriate one upon first use and unzips it into the same directory. So if your ruby gem binaries are installed here:

/usr/lib/ruby/versions/2.6/bin/

The various wkhtmltopdf-binaries will be installed here:

/usr/lib/ruby/versions/2.6/lib/ruby/gems/2.6.0/gems/wkhtmltopdf-binary-0.12.5.1/bin/

Giving write access whatever user is running your program (e.g. web server, background job processor), e.g. your own personal user in a dev environment, will fix the problem. After the binary is uncompressed, write access can be revoked again if desired.

chmod -R 777 /usr/lib/ruby/versions/2.6/lib/ruby/gems/2.6.0/gems/wkhtmltopdf-binary-0.12.5.1/bin/

Gem Development

Extracting binaries

Hints for extracting binaries from https://wkhtmltopdf.org/downloads.html (dpkg and rpm2cpio is available on Homebrew).

Debian/Ubuntu

dpkg -x wkhtmltox_0.12.5-1.trusty_amd64.deb .

CentOS

rpm2cpio wkhtmltox-0.12.5-1.centos7.x86_64.rpm | cpio -idmv

Archlinux/manjaro

tar -xf wkhtmltox-0.12.6-1.archlinux.x86_64.tar.xz

macOS

xar -xf wkhtmltox-0.12.5-1.macos-cocoa.pkg
cat Payload | gunzip -dc | cpio -i

Compression

Binaries should be compressed with gzip --best after extracting. The matching binary will be extracted on first execution of bin/wkhtmltopdf.

Hints for compressing binaries

Debian/Ubuntu user/local/bin refers to the extracted binaries directory gzip --best -c usr/local/bin/wkhtmltopdf > wkhtmltopdf_ubuntu_22.04.amd64.gz

Testing

To execute gem tests locally, install in your OS:

• Docker
• Docker compose
• Ruby
• Bundler

Then, execute the commands below:

git clone https://github.com/zakird/wkhtmltopdf_binary_gem
cd wkhtmltopdf_binary_gem/
bundle install
bundle exec rake