如何使用Kubernetes运行一个简单的PHP Hello World应用程序

116

巴布卢·艾哈迈德（Bablu Ahmed）

我正在尝试部署和运行一个简单的PHP应用程序，该应用程序只能Hello World通过我的Kubernetes集群显示消息，该集群只是一个主节点集群，不幸的是，我无法做到这一点。

我正在描述我的项目结构-我有一个根项目目录kubernetes-test，在该目录下，我有3个yaml文件，code在该目录下有一个目录，我有一个PHP文件，index.php

hello-world-service.yaml：

apiVersion: v1
kind: Service
metadata:
  name: nginx
  labels:
    tier: backend
spec:
  selector:
    app: nginx
    tier: backend
  type: NodePort
  ports:
  - nodePort: 30500
    port: 80
    targetPort: 80

nginx-deployment.yaml

apiVersion: apps/v1
kind: Deployment
metadata:
  name: nginx
  labels:
    tier: backend
spec:
  replicas: 1
  selector:
    matchLabels:
      app: nginx
      tier: backend
  template:
    metadata:
      labels:
        app: nginx
        tier: backend
    spec:
      volumes:
      - name: code
        hostPath:
          path: /code
      - name: config
        configMap:
          name: nginx-config
          items:
          - key: config
            path: site.conf
      containers:
      - name: nginx
        image: nginx:1.7.9
        ports:
        - containerPort: 80
        volumeMounts:
        - name: code
          mountPath: /var/www/html
        - name: config
          mountPath: /etc/nginx/conf.d

php-deployment.yaml

apiVersion: apps/v1
kind: Deployment
metadata:
  name: php
  labels:
    tier: backend
spec:
  replicas: 1
  selector:
    matchLabels:
      app: php
      tier: backend
  template:
    metadata:
      labels:
        app: php
        tier: backend
    spec:
      volumes:
      - name: code
        hostPath:
          path: /code
      containers:
      - name: php
        image: php:7-fpm
        volumeMounts:
        - name: code
          mountPath: /var/www/html

代码/ index.php

<?php
  echo 'Hello World';

最重要的是，我通过互联网发现了这些东西。

当我运行此命令时，kubectl get pods这样的状态ContainerCreating对于Nginx部署将永远显示

NAME                    READY   STATUS              RESTARTS   AGE
nginx-64c9df788f-jxwzx   0/1     ContainerCreating    0          12h
php-55f974bb4-qvv9x      1/1     Running              0          25s

命令： kubectl describe pod nginx-64c9df788f-jxwzx

输出：

Name:           nginx-64c9df788f-jxwzx
Namespace:      default
Priority:       0
Node:           bablu-node/192.168.43.123
Start Time:     Mon, 11 May 2020 03:20:58 +0600
Labels:         app=nginx
                pod-template-hash=64c9df788f
                tier=backend
Annotations:    <none>
Status:         Pending
IP:             
IPs:            <none>
Controlled By:  ReplicaSet/nginx-64c9df788f
Containers:
  nginx:
    Container ID:   
    Image:          nginx
    Image ID:       
    Port:           80/TCP
    Host Port:      0/TCP
    State:          Waiting
      Reason:       ContainerCreating
    Ready:          False
    Restart Count:  0
    Environment:    <none>
    Mounts:
      /etc/nginx/conf.d from config (rw)
      /var/run/secrets/kubernetes.io/serviceaccount from default-token-l2zp2 (ro)
      /var/www/html from code (rw)
Conditions:
  Type              Status
  Initialized       True 
  Ready             False 
  ContainersReady   False 
  PodScheduled      True 
Volumes:
  code:
    Type:          HostPath (bare host directory volume)
    Path:          /code
    HostPathType:  
  config:
    Type:      ConfigMap (a volume populated by a ConfigMap)
    Name:      nginx-config
    Optional:  false
  default-token-l2zp2:
    Type:        Secret (a volume populated by a Secret)
    SecretName:  default-token-l2zp2
    Optional:    false
QoS Class:       BestEffort
Node-Selectors:  <none>
Tolerations:     node.kubernetes.io/not-ready:NoExecute for 300s
                 node.kubernetes.io/unreachable:NoExecute for 300s
Events:
  Type     Reason       Age                    From                 Message
  ----     ------       ----                   ----                 -------
  Warning  FailedMount  31m (x14 over 147m)    kubelet, bablu-node  Unable to attach or mount volumes: unmounted volumes=[config], unattached volumes=[default-token-l2zp2 code config]: timed out waiting for the condition
  Warning  FailedMount  16m (x82 over 167m)    kubelet, bablu-node  MountVolume.SetUp failed for volume "config" : configmap "nginx-config" not found
  Warning  FailedMount  6m53s (x44 over 165m)  kubelet, bablu-node  Unable to attach or mount volumes: unmounted volumes=[config], unattached volumes=[code config default-token-l2zp2]: timed out waiting for the condition
  Warning  FailedMount  2m23s (x10 over 163m)  kubelet, bablu-node  Unable to attach or mount volumes: unmounted volumes=[config], unattached volumes=[config default-token-l2zp2 code]: timed out waiting for the condition

命令： kubectl get events -n default

输出：

LAST SEEN   TYPE      REASON              OBJECT                       MESSAGE
18m         Warning   FailedMount         pod/nginx-64c9df788f-jxwzx   MountVolume.SetUp failed for volume "config" : configmap "nginx-config" not found
8m45s       Warning   FailedMount         pod/nginx-64c9df788f-jxwzx   Unable to attach or mount volumes: unmounted volumes=[config], unattached volumes=[code config default-token-l2zp2]: timed out waiting for the condition
4m15s       Warning   FailedMount         pod/nginx-64c9df788f-jxwzx   Unable to attach or mount volumes: unmounted volumes=[config], unattached volumes=[config default-token-l2zp2 code]: timed out waiting for the condition
33m         Warning   FailedMount         pod/nginx-64c9df788f-jxwzx   Unable to attach or mount volumes: unmounted volumes=[config], unattached volumes=[default-token-l2zp2 code config]: timed out waiting for the condition
18m         Normal    Scheduled           pod/php-55f974bb4-qvv9x      Successfully assigned default/php-55f974bb4-qvv9x to bablu-node
18m         Normal    Pulled              pod/php-55f974bb4-qvv9x      Container image "php:7-fpm" already present on machine
18m         Normal    Created             pod/php-55f974bb4-qvv9x      Created container php
18m         Normal    Started             pod/php-55f974bb4-qvv9x      Started container php
18m         Normal    SuccessfulCreate    replicaset/php-55f974bb4     Created pod: php-55f974bb4-qvv9x
18m         Normal    ScalingReplicaSet   deployment/php               Scaled up replica set php-55f974bb4 to 1

谁能帮帮我吗？提前致谢！！

请问ROF

我运行了您的环境，这是我发现的主要问题：

首先，您没有部署nginx-config，但这只是您的第一个问题，很容易解决（在下面的示例中有更多信息）。
第二个问题（我认为是主要问题）是HostPath：
- 正如我在这里所解释的，HostPath要求容器进程以root身份运行。
- php-fpm运行，www-data因此/code如果通过挂载此文件夹，他将无法使用挂载文件hostPath。

从这里，我们的选择是：

烘烤的图像内的php文件（或作为configmap）和运行在相同的吊舱都nginx的和PHP（共享一个emptydir文件夹），更有关本手册中这一过程：PHP-FPM，Nginx的，Kubernetes，和泊坞-而一方面，它涉及创建一个新的Docker映像，另一方面，如果您还没有存储映像，则无需配置它。
使用外部存储将文件挂载到永久卷中，然后从外部存储库下载php文件。这种方法要求nginx和php在同一节点上运行-因为存储是RWO，这意味着只能以读写方式安装在一个节点上。由于您的设置位于单个节点上，因此在本示例中将使用此方法。

我试图重现您的示例，但是我必须进行一些更改。这些是文件：

cm-nginx.yaml：

apiVersion: v1
kind: ConfigMap
metadata:
  name: nginx-config
  labels:
    tier: backend
data:
  config : |
    server {
      index index.php index.html;
      error_log  /var/log/nginx/error.log;
      access_log /var/log/nginx/access.log;

      root /code;

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

      location ~ \.php$ {
          try_files $uri =404;
          fastcgi_split_path_info ^(.+\.php)(/.+)$;
          fastcgi_pass php:9000;
          fastcgi_index index.php;
          include fastcgi_params;
          fastcgi_param SCRIPT_FILENAME $document_root$fastcgi_script_name;
          fastcgi_param PATH_INFO $fastcgi_path_info;
        }
    }

root /code 指向要查找的目录 index.php
fastcgi_pass php:9000指向称为php服务监听的服务port 9000。

存储：

这是可变的，具体取决于您使用的存储类型。Minikube带有开箱即用配置的存储提供程序和storageclass。而且，尽管称为minikube存储提供程序，但minikube-hostpath它是一种CSI，它不需要在容器级别上的root访问权即可运行。

话虽如此，这是pvc.yaml：

apiVersion: v1
kind: PersistentVolumeClaim
metadata:
  name: code
spec:
  accessModes:
  - ReadWriteOnce
  resources:
    requests:
      storage: 1Gi
  storageClassName: standard

请注意，这standard是内置在minikube中的动态存储提供程序的名称。我们在这里要做的是创建一个PVC，以code供我们的应用程序运行。

php.yaml：

apiVersion: apps/v1
kind: Deployment
metadata:
  name: php
  labels:
    tier: backend
spec:
  replicas: 1
  selector:
    matchLabels:
      app: php
      tier: backend
  template:
    metadata:
      labels:
        app: php
        tier: backend
    spec:
      volumes:
      - name: code
        persistentVolumeClaim:
          claimName: code
      containers:
      - name: php
        image: php:7-fpm
        volumeMounts:
        - name: code
          mountPath: /code
      initContainers:
      - name: install
        image: busybox
        volumeMounts:
        - name: code
          mountPath: /code
        command:
        - wget
        - "-O"
        - "/code/index.php"
        - https://raw.githubusercontent.com/videofalls/demo/master/index.php

在这里，我们使用busyboxinitContainer来获取此php文件（与您使用的php文件相同）并将其保存在已安装的卷中/code。
PHP服务svc-php.yaml：

apiVersion: v1
kind: Service
metadata:
  name: php
  labels:
    tier: backend
spec:
  selector:
    app: php
    tier: backend
  ports:
  - protocol: TCP
    port: 9000

Nginx部署nginx.yaml：

apiVersion: apps/v1
kind: Deployment
metadata:
  name: nginx
  labels:
    tier: backend
spec:
  replicas: 1
  selector:
    matchLabels:
      app: nginx
      tier: backend
  template:
    metadata:
      labels:
        app: nginx
        tier: backend
    spec:
      volumes:
      - name: code
        persistentVolumeClaim:
          claimName: code
      - name: config
        configMap:
          name: nginx-config
          items:
          - key: config
            path: site.conf
      containers:
      - name: nginx
        image: nginx:1.7.9
        ports:
        - containerPort: 80
        volumeMounts:
        - name: code
          mountPath: /code
        - name: config
          mountPath: /etc/nginx/conf.d

这里的关键点，是安装PVC叫code上mountPath /code和configmap我们正在创建作为monted一个名为文件site.conf夹内/etc/nginx/conf.d

Nginx服务svc-nginx.yaml：

apiVersion: v1
kind: Service
metadata:
  name: nginx
  labels:
    tier: backend
spec:
  type: NodePort
  selector:
    app: nginx
    tier: backend
  ports:
  - protocol: TCP
    port: 80

我正在使用NodePort简化输出测试。

再生产：

让我们创建文件：首先是configmap和pvc，因为Pod正确启动需要它们，然后是服务和部署：

$ ls
cm-nginx.yaml  nginx.yaml  php.yaml  pvc.yaml  svc-nginx.yaml  svc-php.yaml

$ kubectl apply -f cm-nginx.yaml 
configmap/nginx-config created

$ kubectl apply -f pvc.yaml 
persistentvolumeclaim/code created

$ kubectl get cm
NAME           DATA   AGE
nginx-config   1      52s

$ kubectl get pvc
NAME   STATUS   VOLUME                                     CAPACITY   ACCESS MODES   STORAGECLASS   AGE
code   Bound    pvc-b63559a0-a306-46f2-942b-0a063bc4ab6b   1Gi        RWO            standard       17s

$ kubectl apply -f svc-php.yaml 
service/php created

$ kubectl apply -f svc-nginx.yaml 
service/nginx created

$ kubectl apply -f php.yaml 
deployment.apps/php created

$ kubectl get pods
NAME                   READY   STATUS    RESTARTS   AGE
php-69d5c956ff-8tjfn   1/1     Running   0          5s

$ kubectl apply -f nginx.yaml 
deployment.apps/nginx created

$ kubectl get pods
NAME                     READY   STATUS    RESTARTS   AGE
nginx-6854dcb7db-75zxt   1/1     Running   0          4s
php-69d5c956ff-8tjfn     1/1     Running   0          22s

$ kubectl get svc
NAME         TYPE        CLUSTER-IP      EXTERNAL-IP   PORT(S)        AGE
nginx        NodePort    10.107.16.212   <none>        80:31017/TCP   41s
php          ClusterIP   10.97.237.214   <none>        9000/TCP       44s

$ minikube service nginx --url
http://172.17.0.2:31017

$ curl -i http://172.17.0.2:31017
HTTP/1.1 200 OK
Server: nginx/1.7.9
Date: Thu, 28 May 2020 19:04:48 GMT
Content-Type: text/html; charset=UTF-8
Transfer-Encoding: chunked
Connection: keep-alive
X-Powered-By: PHP/7.4.6

Demo Test

在这里，我们可以看到由PHP 7驱动的nginx服务器curl返回200 OK的信息以及index.php文件的内容。

我希望它可以帮助您对这种情况有更清晰的了解。

如有任何疑问，请在评论中告诉我。

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