Using multiple configuration files with Jekyll

When building this site I wanted to use jekyll-minifier to keep the page size small. However, it increases the build time significantly which is a pain during development.

Thankfully Jekyll can accept multiple configuration files at a time.

The following command will start a Jekyll server with the standard _config.yml configuration as well as _config.development.yml.

bundle exec jekyll serve --drafts --watch --config=_config.yml,_config.development.yml

Anything in the development configuration will override the base values in _config.yml.

Examples

The production & development configurations for this site look like this:

_config.production.yml

gems:
  - jekyll-minifier

_config.development.yml

livereload: true
gems:
  - jekyll-livereload

Cutting jekyll-minifier from development cuts page generation times from 10 seconds to about 0.8. Coupled with jekyll-livereload it makes previewing site changes much easier.

Updated Makefile

This changes the build and serve parts of the Makefile¹ to look like this:

build:
	bundle exec jekyll build --config=_config.yml,_config.production.yml

serve:
	bundle exec jekyll serve --drafts --watch --config=_config.yml,_config.development.yml