php-fpm: File not found in kubernetes

Question

I'm trying to set a k8s deployment with 2 pods (nginx + php-fpm), but I can't get php-fpm to execute the php scripts. The webpage displays File not found., and in logs :

• fpm pod : 192.168.3.187 - 13/Nov/2020:16:44:06 +0000 "GET /index.php" 404
• nginx pod : 2020/11/13 16:44:06 [error] 20#20: *1 FastCGI sent in stderr: "Primary script unknown" while reading response header from upstream, client: 192.168.1.45, server: _, request: "GET / HTTP/1.1", upstream: "fastcgi://10.98.178.35:9000", host: "192.168.1.220"

The .html files are served as expected.

Without the Location ~ \.php$ server block of nginx I'm able to download .php files, so the problem is really with php-fpm; when entering the container, I can see the scripts are present.

In my deployment, a PersistentVolume on an NFS is mounted on both pods, in /app. Nginx is configured with this configMap :

  default.conf: |
    server {
    listen       80 default_server;
    server_name  _;

    add_header X-Backend-Server $hostname;
    
    root   /app;
    index index.php index.html;
 
         location / {
          try_files $uri $uri/ =404;
        }
        location ~ \.php$ {
          include fastcgi_params;
          fastcgi_param REQUEST_METHOD $request_method;
          fastcgi_param SCRIPT_FILENAME $document_root$fastcgi_script_name;
          fastcgi_pass phpfpm-deploy-svc.default.svc.cluster.local:9000;
        }
    }

Where phpfpm-deploy-svc.default.svc.cluster.local is the DNS resolution of the PHP-FPM service (irrelevant to paste the service code).

php-fpm is a classic deployment :

spec:
      containers:
      - name: phpfpm
        image: php:7.3-fpm
        ports:
          - containerPort: 9000
        volumeMounts:
          - name: nfs-volume
            mountPath: /app
      volumes:
        - name: nfs-volume
          persistentVolumeClaim:
            claimName: nfs-pvc

with its own service :

apiVersion: v1
kind: Service
metadata:
  name: phpfpm-deploy-svc
spec:
  ports:
  - port: 9000
  selector:
    app: phpfpm-deploy
  type: ClusterIP

Most of the solutions seen here are related to the line fastcgi_param SCRIPT_FILENAME $document_root$fastcgi_script_name;: that's possible, but I still has to find a working one.

Without k8s (only docker-compose), I can create this configuration witout issue.

Answer 1

Well, my code above is working fine : the NFS server was the problem, it wasn' doing any mapping on users.

So I was able, from containers, to list the files on the NFS volume as root... but not as www-data, which is the user running php-fpm.

Setting correct mapping on the NFS volume solved it.