I am building an php image containing a composer magento installation. The content is stored in /var/www/html of the image. Now I have a Php-Image and some deployment files. But the contents of the images /var/www/html folder are not shown in any created POD. First I was thinking, that I have to create a volume in the PHP image, mapping to the /var/www/html path. But that did not help (but it seems logical to me).

Maybe there is a problem with the persistent volume claim? I read, that I have to create a volume in the php and nginx container with the same /var/www/html path, so that php content can be executed by nginx, so I did that. But now I am not sure if that is really the way to do it and it interferes with the PVC.

PHP Docker-Image

# image
FROM php:7.1-fpm

# envs
ENV INSTALL_DIR /var/www/html

# install composer
RUN curl -sS https://getcomposer.org/installer | php \
&& mv composer.phar /usr/local/bin/composer

# install libraries
... shortended ...

# set memory limits
RUN echo "memory_limit=2048M" > /usr/local/etc/php/conf.d/memory-limit.ini

# clean apt-get
RUN apt-get clean && rm -rf /var/lib/apt/lists/* /tmp/* /var/tmp/*

# www-data should own /var/www
RUN chown -R www-data:www-data /var/www

# switch user to www-data 
USER www-data

# copy sources with proper user
COPY --chown=www-data ./magento2/composer $INSTALL_DIR

# set working dir
WORKDIR $INSTALL_DIR

RUN composer install

# chmod directories
RUN chmod u+x bin/magento

# switch back
USER root

VOLUME $INSTALL_DIR

Deployments 1. Persistent Volume Claim

    apiVersion: v1
    kind: PersistentVolume
    metadata:
      name: pv-volume-magento
    spec:
      capacity:
        storage: 50Gi
       accessModes:
        - ReadWriteOnce

2. PHP Deployment (using the build image with the web application)

    apiVersion: apps/v1
    kind: Deployment
    metadata:
      name: php
      labels:
        app: php
    spec:
      replicas: 1
      selector:
        matchLabels:
          app: php
      template:
        metadata:
          labels:
            app: php
            tier: frontend
        spec:
          containers:
            - name: php-mage
              image: php-mage:latest 
              imagePullPolicy: Never
          volumeMounts:
            - name: magento2-persistent-storage
              readOnly: false
              mountPath: /var/www/html
           volumes:
             - name: magento2-persistent-storage
               persistentVolumeClaim:
               claimName: magento2-volumeclaim

3. Nginx Deployment

    apiVersion: apps/v1
    kind: Deployment
    metadata:
      name: nginx
      labels:
        app: nginx
    spec:
      replicas: 1
      selector:
        matchLabels:
          app: nginx
      template:
        metadata:
          labels:
          app: nginx
          tier: frontend
        spec:
          containers:
            - name: nginx
              image: nginx:latest
              ports:
                - containerPort: 80
                - containerPort: 443

              volumeMounts:
                - name: magento2-persistent-storage
                  readOnly: false
                  mountPath: /var/www/html

                - name: nginx-config-volume
                  mountPath: /etc/nginx/nginx.conf
                  subPath: nginx.conf

                - name: nginx-site-config-volume
                  mountPath: /etc/nginx/sites-enabled/default.conf
                  subPath: default.conf

                - name: fastcgi-snippet-volume
                  mountPath: /etc/nginx/snippets/fastcgi-php.conf
                  subPath: fastcgi-php.conf

    volumes:
      - name: magento2-persistent-storage
        persistentVolumeClaim:
          claimName: magento2-volumeclaim

       - name: nginx-config-volume
         configMap:
           name: nginx-config

        - name: nginx-site-config-volume
          configMap:
            name: nginx-site-config

        - name: fastcgi-snippet-volume
          configMap:
            name: nginx-fastcgi-config

EDIT: I realized, when I am using subPath in the php-deployment.yaml like that:

              volumeMounts:
                - name: magento2-persistent-storage
                  readOnly: false
                  mountPath: /var/www
                  subPath: html

My content is available in the PHP Pod. But I can't add the same logic to the nginx deployment, because it overwrites the contents and the folder is empty again.

Now, a step further, but still the question how to do this correctly. Do I have to share a mountPath between nginx and php?