Gojekyll

“It is easier to write an incorrect program than understand a correct one.” - Alan Perlis

Gojekyll is a clone of the Jekyll static site generator, written in the Go programming language. It provides build and serve commands, with directory watch and live reload for the latter.

	Gojekyll	Jekyll	Hugo
Stable		✓	✓
Fast	✓ [~20×Jekyll]		✓
Template language	Liquid	Liquid	Go templates
Jekyll compatibility	partial	✓
Plugins	some	yes	?
Runs on Windows		✓	✓
Implementation language	Go	Ruby	Go

• Gojekyll
  • Installation
  • Usage
  • Status
    • Current Limitations
    • Other Differences
    • Feature Checklist
  • Contributing
  • Attribution
  • Related
  • License

Installation

First-time install:

1. Install go. (On macOS running Homebrew, brew install go is easier than the Install instructions on the Go site.)
2. go get osteele/gojekyll
3. [Optional] To use the {% highlight %} tag, you also need Pygments. pip install Pygments.

Update to the latest version:

• go get -u github.com/osteele/liquid github.com/osteele/gojekyll/cmd/gojekyll

[Optional] Install command-line autocompletion:

# Bash:
eval "$(gojekyll --completion-script-bash)"
# Zsh:
eval "$(gojekyll --completion-script-zsh)"

Usage

gojekyll build       # builds the site in the current directory into _site
gojekyll serve       # serve the app at http://localhost:4000; reload on changes
gojekyll help
gojekyll help build

Status

This project is at an early stage of development.

It works on the GitHub Pages sites that I care about, and it looks credible on a spot-check of other Jekyll sites.

Current Limitations

Missing features:

• Themes
• Excerpts
• Pagination
• Math
• CSV and JSON data files
• Most plugins. (Some plugins are emulated.)
• Liquid tag tablerow.
• Liquid filter scssify
• Markdown features: attribute lists, automatic ids, markdown=1.
• site.data is not sorted.
• Undefined Liquid tags and filters are errors, not warnings.
• Windows compatibility

Also see the detailed status below.

Other Differences

These will probably not change:

By design:

• Having the wrong type in a _config.yml is an error.
• Plugins must be listed in the config file, not a Gemfile.
• serve generates pages on the fly; it doesn't write to the file system.
• Files are cached to /tmp/gojekyll-${USER}, not ./.sass-cache
• Live reload are enabled by default.
• Server watch reload the _config.yml and data files too.
• Jekyll provides an (undocumented) jekyll.version variable to templates. Copying this didn't seem right.
• Incremental build. The emphasis is on optimizing the non-incremental case. This is easier with fewer code paths.

Muzukashii:

• An extensible plugin mechanism – support for plugins that aren't compiled into the executable.

Feature Checklist

• Content
  • Front Matter
  • Posts
    • Categories
    • Tags
    • Drafts
    • Future
    • Related
  • Static Files
  • Variables
  • Collections
  • Data Files
    • CSV
    • JSON
    • YAML
  • Assets
    • Coffeescript
    • Sass/SCSS
• Customization
  • Templates
    • Jekyll filters
      • group_by_exp and scssify
      • everything else
    • Jekyll tags
      • include
      • include_relative
      • link
      • post_url
      • highlight
  • Includes
    • include parameters
    • include variables (e.g. {% include {{ expr }} %})
  • Permalinks
  • Pagination
  • Plugins
    • jekyll-avatar
    • jekyll-coffeescript
    • jekyll-gist (ignores noscript: false)
    • jekyll-live-reload (always on)
    • jekyll-paginate
  • Themes
  • Layouts
• Server
  • Directory watch
• Commands
  • build
    • --source, --destination, --drafts, --future, --unpublished
    • --config, --baseurl, --lsi, --no-watch
    • not planned: --force-polling, --limit-posts, --incremental, JEKYLL_ENV=production
  • clean
  • help
  • serve
    • --open-uri, --host, --port
    • --detach, --baseurl
    • not planned: --incremental, --ssl-*
  • not planned: doctor, import, new, new-theme
• Windows

Also see:

• The feature parity board board lists differences between Jekyll and gojekyll in more detail.
• The plugin board lists the implementation status of common plugins. (Gojekyll lacks an extensible plugin mechanism. The goal is to be able to use it to build Jekyll sites that use the most popular plugins.)
• The Go Liquid feature parity board to see differences between the real Liquid library and the one that is used in gojekyll.

Contributing

Bug reports, test cases, and code contributions are more than welcome. Please refer to the contribution guidelines.

Attribution

Gojekyll uses these libraries:

Package	Author(s)	Usage	License
github.com/jaschaephraim/lrserver	Jascha Ephraim	Live Reload	MIT License
github.com/dchest/cssmin	Dmitry Chestnykh	CSS minimization	BSD 3-clause "New" or "Revised" License
github.com/kyokomi/emoji	kyokomi	jemoji plugin emulation	MIT License
github.com/osteele/liquid	yours truly	Liquid processor	MIT License
github.com/pkg/browser	pkg	serve --open-url option	BSD 2-clause "Simplified" License
github.com/russross/blackfriday	Russ Ross	Markdown processing	Simplified BSD License
github.com/sass/libsass	Listed here	C port of the Ruby SASS compiler	MIT License
github.com/wellington/go-libsass	Drew Wells	Go bindings for libsass	???
gopkg.in/alecthomas/kingpin.v2	Alec Thomas	command-line arguments	MIT License
gopkg.in/yaml.v2	Canonical	YAML support	Apache License 2.0

In addition, the following pieces of text were taken from Jekyll and its plugins. They are used under the terms of the MIT License.

Source	Use	Description
jekyll help command	gojekyll help text	help text
Jekyll template documentation	test cases	filter examples
jekyll-feed plugin	plugin emulation	feed.xml template
jekyll-redirect-from plugin	plugin emulation	redirect page template
jekyll-sitemap plugin	plugin emulation	sitemap template
jekyll-seo-tag plugin	plugin emulation	feed template

The gopher image in the testdata directory is from Wikimedia Commons. It is used under the Creative Commons Attribution-Share Alike 3.0 Unported license.

In addition to being totally and obviously inspired by Jekyll and its plugins, Jekyll's solid documentation was indispensible --- especially since I wanted to implement Jekyll as documented, not port its source code. The Jekyll docs were always open in at least one tab during development.

Related

Hugo is the pre-eminent Go static site generator. It isn't Jekyll-compatible (-), but it's extraordinarily polished, performant, and productized (+++).

jkl is another Go clone of Jekyll. If I'd found it sooner I might have started this project by forking that one. It's got a better name, too.

Liquid is a pure Go implementation of Liquid templates, that I finally caved and wrote in order to use in this project.

Jekyll, of course.

License

MIT