Running github-pages gem locally with Docker (part 2)

After my first attempt at running the github-pages gem locally, I realized that the docker image in the pages-gem repository is intended for development of the github-pages gem itself. The image contains the source of the github-pages gem and installs it from a local folder, which is not something you need if you only need to run a GitHub Pages site.

For simply running the latest version of the github-pages gem, you can use a docker image which installs the latest version of github-pages from rubygems.org.

The Dockerfile looks like this:

FROM ruby:3.3
COPY Gemfile .
RUN bundle install
WORKDIR /src/site
CMD ["jekyll", "serve", "-H", "0.0.0.0", "-P", "4000"]

The Gemfile looks like this:

source 'https://rubygems.org'
gem 'github-pages', group: :jekyll_plugins
gem 'webrick', '~> 1.8'

The bundle install command will install the gems specified in the Gemfile: the ‘github-pages’ gem will bootstrap all dependencies for setting up a local Jekyll environment in sync with GitHub Pages, and the ‘webrick’ gem is required by Jekyll but no longer included with Ruby 3 so needs to be installed separately.

You can build the docker image and run it from the site root folder like this:

git clone https://gist.github.com/0b345a2656abe079c322ad0a90a32c61.git github-pages-docker
cd github-pages-docker
docker build -t gh-pages .
cd /github-pages-site
docker run --rm -it -p 4000:4000 -v ${PWD}:/src/site gh-pages

To make things easier to run, you can place this docker compose.yaml file at the root of the site and simply run docker compose up:

services:
  gh-pages:
    build:
      context: https://gist.github.com/0b345a2656abe079c322ad0a90a32c61.git
      dockerfile: Dockerfile.alpine
    ports:
      - "4000:4000"
    volumes:
      - "./:/src/site"

Auto-regeneration did not work for me when running the site on Windows, i.e. the site was not automatically rebuilt and I had to restart Jekyll on each file change. The workaround is to use the --force_polling flag which can be specified in the startup command like this:

services:
  gh-pages:
    build:
      context: https://gist.github.com/0b345a2656abe079c322ad0a90a32c61.git
      dockerfile: Dockerfile.alpine
    command: sh -c "jekyll serve -H 0.0.0.0 -P 4000 --watch --force_polling"
    ...

GitHub Gist: https://gist.github.com/pmarinova/0b345a2656abe079c322ad0a90a32c61