edge-docker-php

Provided Software

• FrankenPHP (PHP + Caddy)
• Composer

Configuration Options

Most configuration can be done with environment variables. Here are some of the available non-standard options:

Environment	Default	Description
PHP_DISPLAY_ERRORS	Off	Display PHP errors in the browser, not recommended for production
PHP_OPCACHE_VALIDATE	Off	Forces OPcache to check for updates on every request, turn Off for production
PHP_TIMEZONE	Europe/London	Specify the PHP date.timezone
PHP_MEMORY_LIMIT	2G	Specify the PHP memory limit
WEB_ROOT	/var/www	Set's the web server root directory
WEB_PUBLIC	-	A suffix to the WEB_ROOT to only serve files from this location
SMTP_HOST	smtp.mailtrap.io	Set SMTP hostname (uses MSMTP for sendmail)
SMTP_PORT	2525	Set SMTP port
SMTP_USER	-	Set SMTP username
SMTP_FROM	-	Set SMTP envelope-from header
SMTP_PASS	-	Set SMTP password
SMTP_TLS	On	Enable TLS support, by default STARTTLS is enabled on port 587
SMTP_CHECK_CERTS	On	Specifying Off will disable SMTP TLS certificate checks

FrankenPHP Configuration

This repo publishes outeredge/edge-docker-php:8.3-frankenphp and :8.4-frankenphp. These variants run FrankenPHP (Caddy + PHP, single process) and are intended for Google Cloud Run and similar serverless container platforms.

There are also -frankenphp-super variants that use supervisor to run FrankenPHP alongside sidecars like Valkey and Google Cloud SQL Proxy.

Environment	Default	Description
CADDY_ADMIN	off	Caddy admin API socket (e.g. localhost:2019 for live inspection)
CADDY_AUTO_HTTPS	off	TLS strategy: on for ACME certs, off for upstream termination (Cloud Run, etc.)
CADDY_GLOBAL_OPTIONS	-	Global escape hatch for debug or custom order directives
CADDY_EXTRA_CONFIG	-	Top-level escape hatch for named snippets or additional sites
CADDY_SERVER_EXTRA_DIRECTIVES	-	Extra directives/overrides (e.g. header, basicauth, X-Robots-Tag)
CADDY_CONF	default	App-specific config from /etc/caddy/conf.d/${CADDY_CONF}.caddy
CADDY_ENCODINGS	zstd br gzip	Space-separated list of compression encodings
FRANKENPHP_CONFIG	-	Runtime tuning, e.g. num_threads 8 or worker /var/www/public/index.php 4
MAX_REQUEST_SIZE	32MB	Maximum inbound request body size (Cloud Run limit is 32MB)
PORT	8080	Note, services like Cloud Run set this automatically
SERVER_NAME	:$PORT	The domain or port to bind to (e.g. app.example.com)

To add app-level Caddy rules, drop a file at $WEB_ROOT/Caddyfile - it is imported automatically.

What's different

• Single process (standard variant): FrankenPHP runs as PID 1. No supervisord, no PHP-FPM, no cron, no SSH, no Valkey sidecar, no sudo.
• Supervisor variant (-frankenphp-super): Runs supervisord as PID 1 with Valkey and Cloud SQL Proxy included.
• Runs as non-root user edge with CAP_NET_BIND_SERVICE removed - cannot bind privileged ports.
• Read-only-rootfs friendly.
• Debian base image.

Additional Site Blocks

To add entirely new site blocks (e.g. for an admin domain, metrics endpoint, or monitoring), drop .caddyfile files into /etc/caddy/Caddyfile.d/. These are imported at the top level, outside of the primary site block.