Deploying PHP on Kubernetes: A Basic Guide for Beginners

Deploying PHP on Kubernetes: A Basic Guide for Beginners

Kubernetes (K8s) has become the de facto standard for container orchestration. If you are a PHP developer, sooner or later you will face the need to deploy your application in a cluster. In this guide, we will walk through how to turn a regular PHP application into a full-fledged service running under Kubernetes. You will learn how to prepare a Docker image, write manifests, and run it all in a local cluster (e.g., Minikube).

We will use the classic stack: PHP-FPM for processing PHP scripts and NGINX as a web server. This will allow us to achieve high performance and flexibility.

1. Preparing the PHP Application and Docker Image

The first step is packaging your PHP code into a Docker container. We will create two images: one for PHP-FPM and one for NGINX (or use a single image with a supervisor, but for beginners, separating them is easier).

Create a Dockerfile for PHP-FPM:

FROM php:8.2-fpm-alpine\n\n# Install extensions\nRUN docker-php-ext-install pdo_mysql mysqli opcache\n\n# Copy application code\nCOPY . /var/www/html\n\n# PHP settings\nCOPY php.ini /usr/local/etc/php/conf.d/custom.ini\n\nWORKDIR /var/www/html\n\nEXPOSE 9000\nCMD ["php-fpm"]

For NGINX, create a separate Dockerfile:

FROM nginx:alpine\n\n# Copy configuration\nCOPY nginx.conf /etc/nginx/nginx.conf\nCOPY default.conf /etc/nginx/conf.d/default.conf\n\n# Static files (if any)\nCOPY public/ /var/www/html/public/\n\nEXPOSE 80\nCMD ["nginx", "-g", "daemon off;"]

Don't forget the default.conf file for NGINX, which proxies requests to PHP-FPM:

server {\n    listen 80;\n    server_name _;\n    root /var/www/html/public;\n    index index.php;\n\n    location / {\n        try_files $uri $uri/ /index.php?$args;\n    }\n\n    location ~ \\.php$ {\n        fastcgi_pass php-service:9000;  # service name in K8s\n        fastcgi_index index.php;\n        fastcgi_param SCRIPT_FILENAME $document_root$fastcgi_script_name;\n        include fastcgi_params;\n    }\n}

Build the images with the command:

docker build -t my-php-app:latest -f Dockerfile.php .\ndocker build -t my-nginx:latest -f Dockerfile.nginx .

2. Kubernetes Basics: Pods, Deployments, and Services

Before writing manifests, let's understand the basic K8s objects:

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• Pod — the smallest deployable unit, one or more containers.
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• Deployment — manages Pod replicas, provides updates and rollbacks.
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• Service — a stable access point to Pods (inside the cluster or externally).
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For our PHP application, we will create two Deployments: one for PHP-FPM and one for NGINX. Then we will link them through an internal Service.

3. Writing Manifests for PHP and NGINX

Create a file php-deployment.yaml:

apiVersion: apps/v1\nkind: Deployment\nmetadata:\n  name: php-app\nspec:\n  replicas: 2\n  selector:\n    matchLabels:\n      app: php-app\n  template:\n    metadata:\n      labels:\n        app: php-app\n    spec:\n      containers:\n      - name: php-fpm\n        image: my-php-app:latest\n        ports:\n        - containerPort: 9000\n        env:\n        - name: DB_HOST\n          value: "mysql-service"  # example environment variable\n        - name: DB_NAME\n          value: "mydb"\n        resources:\n          requests:\n            memory: "128Mi"\n            cpu: "250m"\n          limits:\n            memory: "256Mi"\n            cpu: "500m"\n---\napiVersion: v1\nkind: Service\nmetadata:\n  name: php-service\nspec:\n  selector:\n    app: php-app\n  ports:\n  - protocol: TCP\n    port: 9000\n    targetPort: 9000

Now create