Speed up jekyll site generation with rsync

Jekyll doesn’t support incremental generation so if your site contains loads of static assets like image, audios,.. jekyll is gonna stroke everytime you re-generate your site by deleting and re-generate/re-coppying everything. This little trick below will help you speeding up jekyll generation process by skipping all the static assets that you specified, until jekyll comes up with a better solution.

  • Rename your static asset folder with underscore in front. jekyll is going to ignore this when generating site. Assume this folder is named images. You will rename it to be _images.

  • In your _config.yml, add the line below. This line basically means that when re-generating, the folder called images in generated folder is not getting touched.

keep_files: ["images"]
  • Keeping in the source and generated folder in sync with a little plugin and rsync. Created a file name rsync_image_generator.rb in _plugins folder with the content below.
module Jekyll    
  class RsyncImageGenerator < Generator
    def generate(site)
      system('mkdir -p _site');
      system('rsync --archive --delete _img/ _site/img/');

From now on, jekyll will ignore the _images folder in your source and images in _sites folder when generating your site. We keep it in sync by using rsync, which is much better/faster than delete/copy process jekyll is using.

Github Pages does support jekyll gems now but it’s kinda limited.