How to use Kubernetes with PHP?

In recent years, Kubernetes has become one of the important tools for containerized deployment, and PHP is a common language for application development. How to use Kubernetes in PHP has become an important topic. This article will introduce how to use Kubernetes in PHP, including how to create a Kubernetes cluster, how to use Kubernetes to host PHP applications, and how to interact with Kubernetes in PHP applications.

1. Create a Kubernetes cluster

Before using Kubernetes, you need to create a Kubernetes cluster first. To create a Kubernetes cluster, you can choose to use self-hosting or use the Kubernetes service provided by a cloud service provider.

For self-hosting, you can use tools such as Ansible or Terraform to automatically deploy Kubernetes clusters. I won’t go into details here. You can refer to the links provided at the end of the article to learn relevant knowledge by yourself.

For Kubernetes services provided by cloud service providers, such as Alibaba Cloud's container service and Google Cloud's Kubernetes Engine, you can refer to the official documentation to create a Kubernetes cluster.

After the cluster is created, you need to install the kubectl command line tool to manage the Kubernetes cluster. You can download the corresponding kubectl version from the Kubernetes official website and install it according to the documentation.

2. Use Kubernetes to host PHP applications

The steps to use Kubernetes to host PHP applications are as follows:

1. Define Deployment

Deployment is The object used to manage a certain Pod copy in Kubernetes can be simply understood as a Pod controller. When defining a Deployment, you need to specify the image information and number of copies of the application.

The specific definition method is as follows:

apiVersion: apps/v1
kind: Deployment
metadata:
  name: php-app
  labels:
    app: php
spec:
  replicas: 3
  selector:
    matchLabels:
      app: php
  template:
    metadata:
      labels:
        app: php
    spec:
      containers:
      - name: php
        image: php:7.4-apache
        ports:
        - containerPort: 80
        volumeMounts:
          - name: code
            mountPath: /var/www/html
      volumes:
        - name: code
          configMap:
            name: code-config

The above yaml file defines a Deployment named php-app, the number of copies is 3, and the mirror is php:7.4-apache. Port 80 is exposed in the container and a ConfigMap named code is mounted.

2. Define Service

In Kubernetes, Service is used to define the access entrance of a group of Pods and expose ports. When defining a Service, you need to specify the label of the target Pod, as well as the ports and protocols that need to be exposed.

The specific definition method is as follows:

apiVersion: v1
kind: Service
metadata:
  name: php-service
spec:
  selector:
    app: php
  ports:
  - name: http
    port: 80
    protocol: TCP
    targetPort: 80
  type: LoadBalancer

The above yaml file defines a Service named php-service. The label of the target Pod is app: php, the exposed port is 80, and the protocol is TCP. And set the Service type to LoadBalancer.

3. Create ConfigMap

In the definition of Deployment, a ConfigMap named code is specified and the ConfigMap is mounted in the container. ConfigMap is used to store configuration information, etc., and can be created through yaml files or the kubectl command line tool.

The specific creation method is as follows:

apiVersion: v1
kind: ConfigMap
metadata:
  name: code-config
data:
  index.php: |
    <?php
    echo "Hello, Kubernetes!";

The above yaml file defines a ConfigMap named code-config, which contains a file named index.php with the content of "Hello, Kubernetes !".

4. Deploy the application

After completing the preceding definition, you can use the kubectl apply command to deploy the application to the Kubernetes cluster.

The specific commands are as follows:

kubectl apply -f deployment.yaml
kubectl apply -f service.yaml
kubectl apply -f configmap.yaml

After the application deployment is completed, you can use the kubectl get command to view the status of the application.

3. Interacting with Kubernetes in PHP applications

In PHP applications, you can use the Kubernetes PHP client library officially provided by Kubernetes to interact with Kubernetes. The Kubernetes PHP client library encapsulates the Kubernetes API and can easily operate Kubernetes.

Before using the Kubernetes PHP client library, you need to install dependencies. You can use the Composer tool to install dependencies.

The specific installation method is as follows:

composer require kubernetes/client-php

After installing the dependencies, you can use the Kubernetes PHP client library in your PHP application. The following is a simple example to get all Namespaces in the Kubernetes cluster.

use KubernetesClient;
use KubernetesClientConfiguration;
use KubernetesClientApiCoreV1Api;

$config = new Configuration();
$config->setHost('https://kubernetes.example.com');
$config->setUsername('user');
$config->setPassword('password');

$client = new Client($config);
$coreV1Api = new CoreV1Api($client);

$namespaces = $coreV1Api->listNamespace()->getItems();

foreach ($namespaces as $namespace) {
    echo $namespace->getMetadata()->getName() . "
";
}

The above code creates a Kubernetes API client through the Kubernetes PHP client library, and accesses the listNamespace method in CoreV1API through the client to obtain all Namespaces in the Kubernetes cluster. In actual applications, Kubernetes can be operated in a similar way.

This article briefly introduces how to use Kubernetes in PHP, including creating a Kubernetes cluster, using Kubernetes to host PHP applications, and interacting with Kubernetes in PHP applications. Hope it helps readers.

Reference link:

1. Kubernetes Chinese documentation: https://kubernetes.io/zh/docs/home/
2. Ansible official website: https://www .ansible.com/
3. Terraform official website: https://www.terraform.io/
4. Alibaba Cloud Container Service: https://www.aliyun.com/product/container-service
5. Google Cloud Kubernetes Engine: https://cloud.google.com/kubernetes-engine
6. Kubernetes PHP client library: https://github.com/kubernetes-client/php

The above is the detailed content of How to use Kubernetes with PHP?. For more information, please follow other related articles on the PHP Chinese website!