i've problem when i run a php deployment with kubernetes becouse don't load the modules or extensions libraries.

My deployment file is this:

apiVersion: apps/v1
kind: Deployment
metadata:
  name: php
  labels:
    app: php
spec:
  selector:
    matchLabels:
      app: php
  replicas: 1
  template:
    metadata:
      labels:
        app: php
    spec:
      containers:
      - name: php
        image: php:7-fpm
        env:
          - name: PHP_INI_SCAN_DIR
            value: :/usr/local/etc/php/conf.custom
        ports:
        - containerPort: 9000
        lifecycle:
          postStart:
            exec:
              command: ["/bin/sh","-c","docker-php-ext-install pdo pdo_mysql mysqli && docker-php-ext-enable pdo pdo_mysql mysqli"]
        volumeMounts:
          - name: php-conf
            mountPath: /usr/local/etc/php/conf.custom
      volumes:
        - name: php-conf
          configMap:
            name: php

And my ConfigMap is this:

apiVersion: v1
kind: ConfigMap
metadata:
  name: php
  labels:
    app: php
data:
  wordpress-custom.ini: |-
    upload_max_filesize = 100M
    post_max_size = 100M
  default.ini: |-
    extension=pdo_mysql.so
    extension=mysqli.so

Later i go into the Pod with command "exec -it" and i put again "docker-php-ext-enable mysqli" to check it, but i receive the message "warning: mysqli (mysqli.so) is already loaded!", but when i run the "phpinfo()" command, i see "upload_max_filesize = 100M" and "post_max_size = 100M" updated, but i can't see modules enabled.

What i can do? very thank's