Deploying PHP on Kubernetes: A Basic Guide for Developers

Deploying PHP on Kubernetes: A Basic Guide

Modern web development increasingly requires scalable and fault-tolerant solutions. Kubernetes (K8s) has become the de facto standard for container orchestration. If you are a PHP developer and want to learn how to deploy your applications to Kubernetes, this guide is for you. We will go from creating a Docker image to deploying a full-fledged PHP service in a cluster.

Why Deploy PHP on Kubernetes?

Kubernetes provides several advantages for PHP applications:

• Automatic Scaling: K8s can increase the number of pods when load increases and decrease it when load drops.
• Self-Healing: If a container fails, Kubernetes automatically restarts it.
• Configuration Management: Environment variables and configuration files can be easily centralized using ConfigMap and Secrets.
• Simplified Updates: Rolling updates allow you to update the application without downtime.

This is especially relevant for PHP, as many legacy projects are difficult to scale using traditional methods.

Step 1: Containerizing the PHP Application

Before deploying an application to Kubernetes, it needs to be packaged into a Docker image. Let's look at an example of a simple PHP application using Nginx and PHP-FPM.

Creating the Project Structure

my-php-app/├── src/│   └── index.php├── docker/│   ├── nginx/│   │   └── default.conf│   └── php/│       └── Dockerfile└── docker-compose.yml

Example src/index.php

<?phpecho "Hello from PHP on Kubernetes!";phpinfo();?>

Dockerfile for PHP-FPM

FROM php:8.2-fpm-alpine

RUN docker-php-ext-install pdo pdo_mysql

COPY src/ /var/www/html/

EXPOSE 9000CMD ["php-fpm"]

Nginx Configuration (docker/nginx/default.conf)

server {    listen 80;    server_name localhost;    root /var/www/html;

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

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

Building the Image

docker build -t my-php-app:latest -f docker/php/Dockerfile .

Step 2: Writing Kubernetes Manifests

Now that the image is ready, let's create manifests for deployment in the cluster.

Deployment for PHP-FPM

apiVersion: apps/v1kind: Deploymentmetadata:  name: php-app  labels:    app: php-appspec:  replicas: 3  selector:    matchLabels:      app: php-app  template:    metadata:      labels:        app: php-app    spec:      containers:      - name: php-fpm        image: my-php-app:latest        ports:        - containerPort: 9000        env:        - name: DB_HOST          value: "mysql-service"        - name: DB_NAME          value: "mydb"        resources:          requests:            memory: "128Mi"            cpu: "250m"          limits:            memory: "256Mi"            cpu: "500m"

Deployment for Nginx

apiVersion: apps/v1kind: Deploymentmetadata:  name: nginx  labels:    app: nginxspec:  replicas: 2  selector:    matchLabels:      app: nginx  template:    metadata:      labels:        app: nginx    spec:      containers:      - name: nginx        image: nginx:alpine        ports:        - containerPort: 80        volumeMounts:        - name: nginx-config          mountPath: /etc/nginx/conf.d      volumes:      - name: nginx-config        configMap:          name: nginx-config

ConfigMap for Config