Building self-updating pillar pages in Jekyll with a front matter field

14 Jul 2026

I recently added an index page that groups my home automation and energy posts into sections. The first version was a hand-written list of links, and it had two problems: I had to remember to update it every time I wrote a post, and I got the URL format wrong so half the links 404’d.

The fix was to let Jekyll build the list itself, the same idea as my related posts that work off tags. Here is how it went.

A front matter field, not tags

My first thought was to group by tag, but my tags overlap. A post about Predbat charging a Tesla is tagged both predbat and tesla, so it would appear in two sections at once. I wanted each post in exactly one section, so I added a single custom field instead:

---
layout: post
pillar: energy
title: Setting up Predbat with Solar Assistant
---

Each post gets pillar: energy, pillar: ev or pillar: dashboards.

The loop

On the index page I filter the posts by that field and loop over what comes back:

{% assign energy_posts = site.posts | where: "pillar", "energy" | sort: "date" %}
<ul>
{% for post in energy_posts %}  <li><a href="{{ post.url | relative_url }}">{{ post.title }}</a></li>
{% endfor %}</ul>

where pulls just the posts in that pillar, sort: "date" puts them in order, and {{ post.url }} generates the correct link every time. That last part matters: hardcoding the URLs is what broke my first attempt, and letting Jekyll output the link means I cannot get the format wrong again.

Adding to it

The whole thing now looks after itself:

  • New post in a section? Add pillar: energy (or whichever) to its front matter and it shows up on its own.
  • New section? Copy those few lines of Liquid, change the pillar value and the heading.
  • A whole new topic? Duplicate the page, say a dev.md for development posts, and give those posts pillar: dev.

No more hand-written lists, and no more broken links.

 jekyll

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