Skip to main content
runtime ships a multi-arch image for each supported PHP minor. site-template runs a nightly compat-matrix that confirms each PHP × WP combination still composes cleanly. This page is the source of truth for which combinations are blessed.

​
Supported combinations

PHP 8.3PHP 8.4PHP 8.5
WordPress 6.9supportedsupportedsupported
WordPress 6.8supportedsupportedsupported
PHP < 8.3 is EOL or near-EOL upstream — out of scope. WordPress < 6.8 is below the floor we commit to support. The compat-matrix workflow runs on every PR to site-template plus nightly at 06:00 UTC, so any regression introduced by an upstream WP point release within ~6.8.0 / ~6.9.0 is caught within 24 hours.

​
Tag schema

runtime publishes a multi-arch manifest list (linux/amd64 + linux/arm64) under each of these tags:
TagCadenceExample
:php<X.Y>rolling, on push to main:php8.3, :php8.4, :php8.5
:php<X.Y>-<short-sha>every non-PR push:php8.4-abc1234
:php<X.Y>-v<W.Z>on v*.*.* tag push:php8.4-v0.2.0
:v<W.Z>on v*.*.* tag, default PHP only:v0.2.0
The unprefixed :v<W.Z> channel exists so consumers who don’t care which PHP they’re on can pin a release without encoding the default. The default PHP is 8.3 — see Default-PHP cadence.

​
Picking a PHP

site-template’s Dockerfile defaults the runtime base to the default PHP: 
ARG FP_RUNTIME_IMAGE=ghcr.io/frankenpress/runtime
ARG FP_RUNTIME_VERSION=php8.3
To opt into a different PHP, either pin it in your fork’s Dockerfile: 
ARG FP_RUNTIME_VERSION=php8.4
…or override per-build: 
docker build --build-arg FP_RUNTIME_VERSION=php8.4 -t my-site:test .
Your site’s CI (build.yml) honours the Dockerfile default; per-build overrides only affect the invocation that sets them.
To exercise your actual site code under a non-default PHP before flipping it, run FP_RUNTIME_VERSION=php8.4 make build locally. The compose harness picks up the override.

​
Picking a WordPress minor

WordPress core is composer-installed at site-build time, gated by the roots/wordpress constraint in your fork’s composer.json: 
{
  "require": {
    "roots/wordpress": "^6.8"
  }
}
^6.8 admits both 6.8.x and 6.9.x; composer install resolves to the highest matching point release at build time. To lock onto a specific minor: 
composer require "roots/wordpress:~6.9.0"
~6.9.0 admits patch releases (6.9.1, 6.9.2, …) but not 6.10. Useful when an upstream minor introduces a regression for your stack and you want a stable hold-line until it’s fixed.

​
Default-PHP cadence

The unprefixed :v<W.Z> channel always points at the default PHP, currently 8.3. The default is bumped deliberately — typically ~6 months after a new PHP minor reaches upstream-stable status, long enough for early ecosystem incompatibilities to surface and be patched. A default-PHP bump is a coordinated PR across runtime (the DEFAULT_PHP env in build.yml) and this page. site-template forks do not auto-bump; each site pins its own PHP via the FP_RUNTIME_VERSION build arg.

​
What’s next

runtime

Build args, env vars, and the cache-invalidation contract.

Upgrade flow

git tag → CI → helm upgrade per environment.