Build GitHub Pages locally with Jekyll on a Alpine LXC

When I was trying to build this site locally, my first attempt was on an Alpine LXC. If you think about hosting a simple site, running it in a simple docker image just works. However，all my docker containers are running inside a Debian VM inside Proxmox, and I already have more than 10 containers there. To add some redundancy, I decided to install Jekyll in an Alpine LXC.

Set up the Alpine LXC

To add an Alpine LXC, we can again borrow this convenient script. You can pretty much use the default options. Just two things to note.

1. When installing Ruby packages and building the site, the system may need several hundred MB RAM, so I increased the assigned RAM size to 1 GB.
2. Alpine installation is really compact, so I only gave it 1 GB virtual HD, but it turns out that the repo alone is several MB. With installing Alpine and Ruby packages, the whole LXC quickly took up almost 800 MB on the disk, so I increased the virtual disk to 2 GB.

Install packages

To use Jekyll, here are the thing you will need

apk update
# to build jejyll
apk add ruby ruby-dev libffi-dev alpine-sdk
gem install bundle 

Due to a recent change in the ffi gem, you need run this command to update your lock file to correctly install the ffi gem on Alpine Linux.

bundle lock --add-platform x86_64-linux-musl

Since we are using the root user of the LXC anyway, you do not need sudo or --user-install options. Then you just have to clone your repo, run bundle install, and serve your site with bundle exec jekyll serve --host=0.0.0.0 --incremental --livereload. Note the option --host=0.0.0.0 is needed if you want to access the page from LAN (and you will).

On the other hand, if you only want to serve the site locally not developing, using nginx can save a lot of RAM. In my case, the who LXC only uses less than 15 MB RAM.

You just have to install nginx via

apk add nginx

Create a configuration file, like /etc/nginx/http.d/github-pages.conf. Below is an example configuration

server {
    listen       80;
    server_name jekyll.lan;
    root /var/www/github-pages;
    index  index.html;
    # log files
    access_log  /var/log/nginx/gh_access.log;
    error_log   /var/log/nginx/gh_error.log;
}

Then disable the default page and start nginx

mv /etc/nginx/http.d/default.conf /etc/nginx/http.d/default.conf.disable
# start nginx service
service nginx start
# start nginx when the sytstem boots up
rc-update add nginx default