Probo Example: Ruby / Jekyll

A Probo CI demo that displays the build environment variables Probo injects into a container. Originally a PHP page (src/index.php); now a static Jekyll site.

How it works

Jekyll is a static generator, so there is no request-time PHP. Instead, the environment is captured at build time — which, inside a Probo container, is exactly when the injected variables are present:

• _plugins/probo_env.rb is a Jekyll generator that reads ENV, applies the same filter as the container's envvars-swap.sh (drops APACHE_* and HOME/LANG/PWD/PATH/OLDPWD/SHLVL/_), and exposes the result as site.data.probo.
• index.html renders it with Liquid: documented build variables in one table, secrets / custom variables in another, plus the Ruby version and a "running inside Probo" status pill.

Requirements

• Ruby (targets the highest available — pinned to 4.0.5 in .ruby-version; Jekyll 4.4 supports Ruby 3.3+).
• Bundler.

Build

./build.sh            # builds into ./_site
./build.sh /some/dir  # builds into a custom destination

Preview locally with live values:

BUILD_ID=demo PROBO_ENVIRONMENT=TRUE bundle exec jekyll serve