Missing dirs and files when migrating PHP-Apache2 from Debian to Alpine - dockerfile

Question

I'm trying to migrate a dockerized PHP-Apache2 server from Debian to Alpine.
The Debian dockerfile:
FROM php:7.3.24-apache-buster
COPY conf/php.ini /usr/local/etc/php
RUN apt-get update && apt-get upgrade -y && apt-get install -y \
curl git \
libfreetype6-dev \
libjpeg62-turbo-dev \
libmcrypt-dev \
libxml2-dev \
libpng-dev \
python-setuptools python-dev build-essential python-pip \
libzip-dev
RUN pecl install mcrypt-1.0.2 \
&& docker-php-ext-enable mcrypt \
&& docker-php-ext-configure gd --with-freetype-dir=/usr/include/ --with-jpeg-dir=/usr/include/ \
&& docker-php-ext-install -j$(nproc) gd \
&& docker-php-ext-install mysqli \
&& docker-php-ext-install zip \
&& docker-php-ext-install soap
RUN pip install --upgrade virtualenv && pip install xhtml2pdf
WORKDIR /var/www/app
COPY ./ /var/www/app
RUN cd /var/www/app && \
php -r "copy('https://getcomposer.org/installer', 'composer-setup.php');" && \
php composer-setup.php && \
php -r "unlink('composer-setup.php');" && \
php composer.phar install --ignore-platform-reqs --prefer-dist
COPY ./conf/default.conf /etc/apache2/sites-enabled/000-default.conf
COPY ./conf/cert /etc/apache2/cert
RUN mkdir /var/log/gts && chmod 777 -R /var/log/gts
RUN mv /etc/apache2/mods-available/rewrite.load /etc/apache2/mods-enabled/rewrite.load
RUN mv /etc/apache2/mods-available/ssl.load /etc/apache2/mods-enabled/ssl.load
COPY conf/apache2.conf /etc/apache2/apache2.conf
RUN mv /etc/apache2/mods-available/remoteip.load /etc/apache2/mods-enabled/remoteip.load
EXPOSE 443
The Alpine dockerfile:
FROM webdevops/php-apache:7.3-alpine
COPY conf/php.ini /usr/local/etc/php
RUN apk update && apk upgrade && apk add \
git \
curl \
autoconf \
freetype-dev \
libjpeg-turbo-dev \
libmcrypt-dev \
libxml2-dev \
libpng-dev \
libzip-dev \
py-setuptools \
python3-dev \
build-base \
py-pip \
libzip-dev \
apache2-dev
RUN PHP_AUTOCONF="/usr/bin/autoconf" \
&& pecl install mcrypt-1.0.2 \
&& docker-php-ext-enable mcrypt \
&& docker-php-ext-configure gd --with-freetype-dir=/usr/include/ --with-jpeg-dir=/usr/include/
RUN pip install --upgrade --ignore-installed virtualenv && pip install xhtml2pdf
WORKDIR /var/www/app
COPY ./ /var/www/app
RUN cd /var/www/app && \
php -r "copy('https://getcomposer.org/installer', 'composer-setup.php');" && \
php composer-setup.php && \
php -r "unlink('composer-setup.php');" && \
php composer.phar install --ignore-platform-reqs --prefer-dist
COPY ./conf/default.conf /etc/apache2/sites-enabled/000-default.conf
COPY ./conf/cert /etc/apache2/cert
RUN mkdir /var/log/gts && chmod 777 -R /var/log/gts
RUN mv /etc/apache2/mods-available/rewrite.load /etc/apache2/mods-enabled/rewrite.load \
&& mv /etc/apache2/mods-available/ssl.load /etc/apache2/mods-enabled/ssl.load
COPY conf/apache2.conf /etc/apache2/apache2.conf
RUN mv /etc/apache2/mods-available/remoteip.load /etc/apache2/mods-enabled/remoteip.load
EXPOSE 443
The Alpine build failed:
mv: can't rename '/etc/apache2/mods-available/rewrite.load': No such file or directory
Turns out that the Alpine container:
Has no /etc/apache2/mods-* directories and no *.load files
Has only *.so files in /usr/lib/apache2 (similar to the list of *.so files in /usr/lib/apache2/modules on Debian).
Questions:
Why don't I have *.load files in the Alpine container?
Why don't I have /etc/apache2/mods-* directories in the Alpine container?
Are *.so files equivalent to *.load files?
If the previous is true, then how do I use the *.so files?
PS: I prefer not to change httpd.conf if possible.

Answer 1

I try to answer your questions one by one:
Why don't I have *.load files in the Alpine container?
The load-files normally just contain one line to load the specific module and can be seen as a convenience method to toggle modules with a shell script (a2enmod)
Why don't I have /etc/apache2/mods-* directories in the Alpine container?
Alpine tries to be minimalistic. This also means you should not install modules you don't need. So having modules installed you don't need (e.g. only in mods-available) is bad practice.
Are *.so files equivalent to *.load files?
The so-files are also present in debian and are the modules itself. The load-files are configuration fragments to load these .so files.
If the previous is true, then how do I use the *.so files?
Just take a look into the load-Files. For example, you can load the rewrite module by using this configuration line:
LoadModule rewrite_module modules/mod_rewrite.so
You shouldn't change httpd.conf, your preference is right here. But you can put custom configuration into the /etc/apache2/conf.d and load all your modules there. Just make sure your configfiles there end with a .conf