wicked_pdf does not run on Ubuntu server : wkhtmltopdf: cannot connect to X server

This post helped me to resolve my problem : http://www.stormconsultancy.co.uk/blog/development/generating-pdfs-in-rails-with-pdfkit-and-deploying-to-a-server/

I'm reproducing here the step from this post that helped me to install it :

# first, installing dependencies
sudo aptitude install openssl build-essential xorg libssl-dev

# for 64bits OS
wget http://wkhtmltopdf.googlecode.com/files/wkhtmltopdf-0.9.9-static-amd64.tar.bz2
tar xvjf wkhtmltopdf-0.9.9-static-amd64.tar.bz2
mv wkhtmltopdf-amd64 /usr/local/bin/wkhtmltopdf
chmod +x /usr/local/bin/wkhtmltopdf

He also create an initializer to tell to pdfKit where it is, so this method is for wicked PDF and PDF Kit.

Resolved this problem in this tread https://stackoverflow.com/a/34947479/5320149

I found method to resolve this problem without fake X server. In newest version of wkhtmltopdf dont need X server for work, but it no into official linux repositories.

Solution for Ubuntu 14.04.4 LTS (trusty) i386

$ sudo apt-get install xfonts-75dpi
$ wget https://github.com/wkhtmltopdf/wkhtmltopdf/releases/download/0.12.2.1/wkhtmltox-0.12.2.1_linux-trusty-i386.deb
$ sudo dpkg -i wkhtmltox-0.12.2.1_linux-trusty-i386.deb
$ wkhtmltopdf http://www.google.com test.pdf

Solution for Ubuntu 14.04.4 LTS (trusty) amd64

$ sudo apt-get install xfonts-75dpi
$ wget https://github.com/wkhtmltopdf/wkhtmltopdf/releases/download/0.12.2.1/wkhtmltox-0.12.2.1_linux-trusty-amd64.deb
$ sudo dpkg -i wkhtmltox-0.12.2.1_linux-trusty-amd64.deb
$ wkhtmltopdf http://www.google.com test.pdf

1. Verify you have xvfb installed, or install it using apt-get install xvfb.

2. Create a file called wkhtmltopdf.sh and add the following:

   xvfb-run -a -s "-screen 0 640x480x16" wkhtmltopdf $*
   

   Change the dimensions (640x480x16) to match whatever virtual screen parameters you want it to emulate.

3. Move the shell script to /usr/bin, and set permissions:

   sudo chmod a+x /usr/bin/wkhtmltopdf.sh
   

4. Optionally, you can add a symbolic link in your project directory:

   ln -s /usr/bin/wkhtmltopdf.sh wkhtmltopdf
   

See this and this for reference.