Deploying PHP on Kubernetes: A Practical Basic Guide

Introduction: Why Deploy PHP in Kubernetes?

PHP remains one of the most popular languages for web development. However, as the load and complexity of projects (Laravel, Symfony, Bitrix) grow, the traditional LAMP stack can no longer cope. Kubernetes (K8s) offers a solution: automatic scaling, fault tolerance, zero-downtime deployment, and configuration management.

In this guide, we will walk through the complete cycle of deploying a PHP application in Kubernetes in practice: from creating a Docker image to setting up Ingress. You will learn how to prepare manifests, manage environment variables, and ensure PHP-FPM works in the cluster.

1. Preparing the PHP Application and Docker Image

1.1. PHP Project Structure

For deployment, we need a minimal PHP application. Let's take a classic index.php:

<?php// index.phpecho "Hello from Kubernetes! PHP version: " . phpversion();

Also, create a composer.json (if you are using a framework):

{    "require": {        "php": "^8.1"    }}

1.2. Dockerfile for PHP-FPM

Key point: In Kubernetes, PHP runs via PHP-FPM, while Nginx serves static files. Let's create a Dockerfile:

FROM php:8.2-fpm-alpine

# Install necessary extensionsRUN docker-php-ext-install pdo_mysql mysqli opcache

# Copy application codeCOPY . /var/www/html

# Set permissionsRUN chown -R www-data:www-data /var/www/html

# PHP settingsCOPY php.ini /usr/local/etc/php/conf.d/custom.ini

WORKDIR /var/www/html

EXPOSE 9000CMD ["php-fpm"]

For production, add opcache:

; php.iniopcache.enable=1opcache.memory_consumption=128opcache.max_accelerated_files=10000

1.3. Dockerfile for Nginx

Nginx will proxy requests to PHP-FPM:

FROM nginx:alpine

COPY nginx.conf /etc/nginx/conf.d/default.confCOPY public/ /var/www/html/public

EXPOSE 80

Example nginx.conf:

server {    listen 80;    root /var/www/html/public;    index index.php;

    location / {        try_files $uri $uri/ /index.php?$query_string;    }

    location ~ \\.php$ {        fastcgi_pass php-service:9000;        fastcgi_param SCRIPT_FILENAME $document_root$fastcgi_script_name;        include fastcgi_params;    }}

2. Creating Kubernetes Manifests

2.1. Namespace

Isolate our application:

apiVersion: v1kind: Namespacemetadata:  name: php-app

2.2. ConfigMap for Environment Variables

PHP applications often use environment variables (e.g., for database connection):

apiVersion: v1kind: ConfigMapmetadata:  name: php-config  namespace: php-appdata:  APP_ENV: production  APP_DEBUG: "false"  DB_HOST: mysql-service

2.3. Secret for Sensitive Data

Store passwords and keys in a Secret:

apiVersion: v1kind: Secretmetadata:  name: php-secrets  namespace: php-apptype: Opaquedata:  DB_PASSWORD: cGFzc3dvcmQxMjM=  # base64 "password123"

2.4. Deployment for PHP-FPM

The main component — PHP-FPM:

apiVersion: apps/v1kind: Deploymentmetadata:  name: php-deployment  namespace: php-appspec:  replicas: 2  selector:    matchLabels:      app: php-app  template:    metadata:      labels:        app: php-app    spec:      containers:      - name: php-fpm        image: my-registry/php-app:latest        ports:        - containerPort: 9000        envFrom:        - configMapRef:            name: php-config        - secretRef:            name: php-secrets        resources:          requests:            memory: "128Mi"            cpu: "250m"          limits:            memory: "256Mi