FastCGI Plugin

Type: Domain Plugin Runs: Once for each discovered domain/host

Overview

The FastCGI plugin configures HAProxy to communicate with PHP-FPM and other FastCGI applications. It automatically generates the necessary HAProxy fcgi-app configuration that defines CGI parameters for proper PHP-FPM communication.

Why Use It

Automatically generates HAProxy fcgi-app configuration that defines required CGI parameters for PHP-FPM communication without manual HAProxy configuration.

Configuration Options

Option	Description	Default
enabled	Enable/disable plugin	true
document_root	Document root path	/var/www/html
script_filename	Custom pattern for SCRIPT_FILENAME	%[path] (uses HAProxy's default)
index_file	Default index file	index.php
path_info	Enable PATH_INFO support	true
custom_params	Dictionary of custom FastCGI parameters	(optional)

Configuration Examples

Docker/Docker Compose (TCP connection)

services:
  php-fpm:
    image: php:8.2-fpm
    labels:
      easyhaproxy.http.host: phpapp.local
      easyhaproxy.http.port: 80
      easyhaproxy.http.localport: 9000
      easyhaproxy.http.proto: fcgi
      easyhaproxy.http.plugins: fastcgi
      easyhaproxy.http.plugin.fastcgi.document_root: /var/www/html
      easyhaproxy.http.plugin.fastcgi.index_file: index.php
    volumes:
      - ./app:/var/www/html

Docker/Docker Compose (Unix socket)

services:
  php-fpm:
    image: php:8.2-fpm
    labels:
      easyhaproxy.http.host: phpapp.local
      easyhaproxy.http.socket: /run/php/php-fpm.sock
      easyhaproxy.http.proto: fcgi
      easyhaproxy.http.plugins: fastcgi
      easyhaproxy.http.plugin.fastcgi.document_root: /var/www/html
      easyhaproxy.http.plugin.fastcgi.index_file: index.php
    volumes:
      - ./app:/var/www/html
      - /run/php:/run/php

Custom Document Root and Index File

labels:
  easyhaproxy.http.plugins: fastcgi
  easyhaproxy.http.plugin.fastcgi.document_root: /var/www/myapp/public
  easyhaproxy.http.plugin.fastcgi.index_file: app.php
  easyhaproxy.http.plugin.fastcgi.path_info: true

Kubernetes Annotations

apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
  annotations:
    easyhaproxy.plugins: "fastcgi"
    easyhaproxy.plugin.fastcgi.document_root: "/var/www/html"
    easyhaproxy.plugin.fastcgi.index_file: "index.php"
spec:
  rules:
    - host: phpapp.example.com
      http:
        paths:
          - path: /
            backend:
              service:
                name: php-fpm
                port:
                  number: 9000

Static YAML Configuration

# /etc/haproxy/static/config.yaml
easymapping:
  - host: phpapp.local
    port: 80
    container: php-fpm:9000
    proto: fcgi
    plugins:
      - fastcgi
    plugin_config:
      fastcgi:
        document_root: /var/www/html
        index_file: index.php
        path_info: true

Environment Variables

Configure FastCGI plugin defaults for all domains:

Environment Variable	Config Key	Type	Default	Description
EASYHAPROXY_PLUGIN_FASTCGI_ENABLED	enabled	boolean	true	Enable/disable plugin for all domains
EASYHAPROXY_PLUGIN_FASTCGI_DOCUMENT_ROOT	document_root	string	/var/www/html	Document root path
EASYHAPROXY_PLUGIN_FASTCGI_SCRIPT_FILENAME	script_filename	string	%[path]	Custom pattern for SCRIPT_FILENAME
EASYHAPROXY_PLUGIN_FASTCGI_INDEX_FILE	index_file	string	index.php	Default index file
EASYHAPROXY_PLUGIN_FASTCGI_PATH_INFO	path_info	boolean	true	Enable PATH_INFO support

Note: Environment variables set defaults for ALL domains. To configure per-domain, use container labels or Kubernetes annotations. Custom params (custom_params) cannot be configured via environment variables - use YAML or labels instead.

Generated HAProxy Configuration

The plugin generates a top-level fcgi-app section and a use-fcgi-app directive in the backend:

# Top-level fcgi-app definition (added after defaults, before frontends/backends)
fcgi-app fcgi_phpapp_local
    docroot /var/www/html
    index index.php
    path-info ^(/.+\.php)(/.*)?$

# Backend configuration (added to the backend section)
backend srv_phpapp_local_80
    use-fcgi-app fcgi_phpapp_local
    # TCP connection:
    server srv-0 172.19.0.3:9000 proto fcgi
    # OR Unix socket:
    # server srv-0 /run/php/php-fpm.sock proto fcgi

CGI Parameters

Note: HAProxy automatically sets standard CGI parameters based on the fcgi-app configuration when communicating with PHP-FPM via the FastCGI protocol.

The plugin configures:

• ✅ SCRIPT_FILENAME - Path to PHP script
• ✅ DOCUMENT_ROOT - Document root directory
• ✅ SCRIPT_NAME - Script name from URL
• ✅ REQUEST_URI - Full request URI with query string
• ✅ QUERY_STRING - URL query parameters
• ✅ REQUEST_METHOD - HTTP method (GET, POST, etc.)
• ✅ CONTENT_TYPE & CONTENT_LENGTH - Request body info
• ✅ SERVER_NAME & SERVER_PORT - Server details
• ✅ HTTPS - SSL/TLS status
• ✅ PATH_INFO - Path information (optional)

Important Notes

• Required: Use this plugin together with proto: fcgi parameter for complete PHP-FPM support
• The plugin runs once per domain during the discovery cycle
• HAProxy handles the actual FastCGI protocol communication and CGI parameter transmission

Related Documentation

• Plugin System Overview
• Container Labels Reference