[Rails 4.x] Linuxで、wkhtmltoimage(wkhtmltopdf) を利用して WebサイトのScreenshot を取る ref: http://qiita.com/tsumekoara/items/b683bcc3564fcef8d3af

example.rb

# encoding: utf-8
namespace :screenshot do
  desc "get screenshot from official_url and save tmp/screenshots/"
  task :get => :environment do

    quality       = 100
    aspect_width  = 4
    aspect_height = 3 # height : width = 4 : 3
    width         = 1200
    height        = width * 3 /4

    output_dir = "tmp/screenshots/"

    items.each do |item|
      output_file = "#{item.id}.jpg"
      file_path = output_dir + output_file
      command = "wkhtmltoimage --quality #{quality} --width #{width} --height #{height} #{url} #{file_path}"
      IO.popen("#{command}")
    end
  end

file0.txt

$ sudo yum install -y openssl libX11 libXext libXext.so.6

file1.txt

$ cd /usr/local/src
$ wget http://downloads.sourceforge.net/project/wkhtmltopdf/0.12.2.1/wkhtmltox-0.12.2.1_linux-centos6-amd64.rpm

$ sudo rpm -ivh wkhtmltox-0.12.2.1_linux-centos6-amd64.rpm
error: Failed dependencies:
    xorg-x11-fonts-Type1 is needed by wkhtmltox-1:0.12.2.1-1.x86_64
    xorg-x11-fonts-75dpi is needed by wkhtmltox-1:0.12.2.1-1.x86_64

file2.txt

$ sudo rpm -ivh ftp://rpmfind.net/linux/centos/6.6/os/x86_64/Packages/ttmkfdir-3.0.9-32.1.el6.x86_64.rpm

$ sudo rpm -ivh ftp://rpmfind.net/linux/centos/6.6/os/x86_64/Packages/xorg-x11-fonts-Type1-7.2-9.1.el6.noarch.rpm

$ sudo rpm -ivh ftp://rpmfind.net/linux/centos/6.6/os/x86_64/Packages/xorg-x11-fonts-75dpi-7.2-9.1.el6.noarch.rpm

$ sudo rpm -ivh wkhtmltox-0.12.2.1_linux-centos6-amd64.rpm

file3.txt

# set font files at user home directory 
$ mkdir ~/.fonts
$ cp IPAfont00302.zip ~/.fonts
$ cd ~/.fonts 
$ unzip IPAfont00302.zip 

file4.txt

# clear font cache
$ fc-cache -fv

file5.txt

# confirm installed font
$ fc-list

file6.txt

$ sudo cp ~/.fonts/*.ttf /usr/share/fonts/

file7.txt

$ wkhtmltoimage http://www.google.com hoge.jpg