Firehose

Willem's personal blog — a modular static blog built on Blogex, powered by Phoenix and NimblePublisher.

Posts live as markdown files in git and compile into the BEAM at build time: zero database, zero runtime I/O, sub-millisecond reads.

The project structure is modular, I wanted to have a personal blog, and an easy way to add an 'engineering' blog to fledgling SaaS products, as well as release notes. The release notes now also serve to announce new features on my blog.

Status: Experimental. Works on my server ;-).

Enjoy, Willem van den Ende

Project structure

This is a monorepo with two parts:

firehose/
├── app/                    # Phoenix application (OTP app: :firehose)
│   ├── lib/firehose/       # Application logic
│   ├── lib/firehose_web/   # Web layer (controllers, live views, components)
│   ├── lib/firehose/blogs/ # Blog definitions (engineering, release notes)
│   ├── priv/blog/          # Markdown posts
│   └── mix.exs
├── blogex/                 # Blogex library (multi-blog engine)
│   ├── lib/
│   └── mix.exs
├── Dockerfile              # Deploy build; ARG pins must match mise.toml
├── mise.toml               # Runtime versions (Elixir, Erlang, Node)
└── scripts/check-pins.sh   # Verifies the pin sync; runs in `make check`

Two blogs are configured:

Blog	Route	Description
Engineering	/blog/engineering	Main blog
Release Notes	/blog/releases	What's new in an app

Prerequisites

• Elixir 1.15+ and Erlang/OTP 26+ (managed by mise)
• Node.js (managed by mise, for Tailwind + esbuild assets)
• PostgreSQL 16+ running on localhost:5432

Setup

1. Install runtimes

mise install

This installs Elixir, Erlang, and Node at the versions specified in mise.toml.

Toolchain pins

mise.toml (local dev toolchain) and the Dockerfile ARG pins (deploy builder image) must agree — local builds and deployed images should run the same Elixir/OTP. make check runs scripts/check-pins.sh to verify this; when it reports a MISMATCH, fix the file it names. Upstream drift of these pins (newer Elixir/OTP/Debian releases) is reported separately by dokku-updates firehose check from the dokku-maintenance repo.

2. Start PostgreSQL

You need PostgreSQL running locally with a postgres user (password: postgres).

Option A — Docker (quick):

docker run -d --name firehose-pg -e POSTGRES_USER=postgres -e POSTGRES_PASSWORD=postgres -p 5432:5432 postgres:16

Option B — Dev container:

cd .devcontainer && docker compose up -d db

Option C — System install:

Install PostgreSQL normally and ensure a postgres user with password postgres exists.

3. Install dependencies and set up the database

cd app
mix setup

This runs:

• mix deps.get — fetch Hex and git dependencies
• mix ecto.create — create the firehose_dev database
• mix ecto.migrate — run database migrations
• mix run priv/repo/seeds.exs — seed initial data
• mix assets.setup — install Tailwind and esbuild
• mix assets.build — compile CSS and JS assets

4. Start the server

mix phx.server

Visit localhost:8056 in your browser.

Note: The dev server runs on port 8056 by default. Override with PORT=4000 mix phx.server.

Development commands

All commands below are run from the app/ directory.

Command	Description
mix phx.server	Start the dev server with live reload
iex -S mix	Start an IEx session with the app
mix test	Run the test suite
mix precommit	Run all quality gates (compile, credo, format, test)
mix format	Format Elixir/HEEx code
mix credo --strict	Run Credo static analysis

Writing blog posts

Posts are markdown files with Elixir frontmatter. Place them under app/priv/blog/<blog-name>/:

app/priv/blog/
├── engineering/
│   └── 2026/
│       └── 05-01-hello-world.md
└── release-notes/
    └── 2026/
        └── 05-01-v0-1.md

Frontmatter format:

%{
  title: "Hello World",
  author: "Willem van den Ende",
  tags: ~w(elixir phoenix blogex),
  description: "My first blog post"
}
---


This is my first post. It compiles into the BEAM at build time.

In dev mode, edited .md files trigger live reload automatically.

Blogex

The Blogex library is a multi-blog engine for Phoenix apps, powered by NimblePublisher. See blogex/README.md for full documentation.

License

MIT — see LICENSE