Setting up Gzip compression for Zola + GitLab Pages

As this website is hosted on GitLab pages, I cannot enable Gzip compression on the server side. Previously, I used the jekyll-gzip plugin. Zola does not support plugins and also has no built-in way to enable compression. So I examined how the jekyll-gzip plugin worked: it creates a gzipped version of each file alongside it, e.g.,

bg.css
bg.css.gz
fonts.css
fonts.css.gz
light_styles.css
light_styles.css.gz

This is fairly trivial to implement using a shell script, which I now include in my build process:

#!/usr/bin/zsh

extensions=(".css" ".htm" ".html" ".png" ".jpg" ".jpeg" ".gif" ".svg" ".woff2")

for e in $extensions; do
    for f in $(find ./**/*$e); do
        gzip -vkf --best $f
    done
done

This particular example needs zsh to work, in order to support the ** recursive globbing operator, but this functionality should be fairly easy to replicate in other shells. :)