Dockerfile

FROM php:7.3-apache

# install the PHP extensions we need (https://make.wordpress.org/hosting/handbook/handbook/server-environment/#php-extensions)
RUN set -ex; \
	\
	savedAptMark="$(apt-mark showmanual)"; \
	\
	apt-get update; \
	apt-get install -y --no-install-recommends \
		libjpeg-dev \
		libmagickwand-dev \
		libpng-dev \
		libzip-dev \
	; \
	\
	docker-php-ext-configure gd --with-png-dir=/usr --with-jpeg-dir=/usr; \
	docker-php-ext-install -j "$(nproc)" \
		bcmath \
		exif \
		gd \
		mysqli \
		opcache \
		zip \
	; \
	pecl install imagick-3.4.4; \
	docker-php-ext-enable imagick; \
	\
# reset apt-mark's "manual" list so that "purge --auto-remove" will remove all build dependencies
	apt-mark auto '.*' > /dev/null; \
	apt-mark manual $savedAptMark; \
	ldd "$(php -r 'echo ini_get("extension_dir");')"/*.so \
		| awk '/=>/ { print $3 }' \
		| sort -u \
		| xargs -r dpkg-query -S \
		| cut -d: -f1 \
		| sort -u \
		| xargs -rt apt-mark manual; \
	\
	apt-get purge -y --auto-remove -o APT::AutoRemove::RecommendsImportant=false; \
	rm -rf /var/lib/apt/lists/*

# set recommended PHP.ini settings
# see https://secure.php.net/manual/en/opcache.installation.php
RUN { \
		echo 'opcache.memory_consumption=128'; \
		echo 'opcache.interned_strings_buffer=8'; \
		echo 'opcache.max_accelerated_files=4000'; \
		echo 'opcache.revalidate_freq=2'; \
		echo 'opcache.fast_shutdown=1'; \
	} > /usr/local/etc/php/conf.d/opcache-recommended.ini
# https://codex.wordpress.org/Editing_wp-config.php#Configure_Error_Logging
RUN { \
		echo 'error_reporting = 4339'; \
		echo 'display_errors = Off'; \
		echo 'display_startup_errors = Off'; \
		echo 'log_errors = On'; \
		echo 'error_log = /dev/stderr'; \
		echo 'log_errors_max_len = 1024'; \
		echo 'ignore_repeated_errors = On'; \
		echo 'ignore_repeated_source = Off'; \
		echo 'html_errors = Off'; \
	} > /usr/local/etc/php/conf.d/error-logging.ini

RUN a2enmod rewrite expires headers

# Sendmail alternative msmtp
RUN apt-get update; \
    apt-get install -y ca-certificates msmtp msmtp-mta; \
    apt-get purge -y --auto-remove -o APT::AutoRemove::RecommendsImportant=false; \
    rm -rf /var/lib/apt/lists/*

# Install Composer
RUN php -r "copy('https://getcomposer.org/installer', 'composer-setup.php');"; \
	php -r "if (hash_file('sha384', 'composer-setup.php') === '48e3236262b34d30969dca3c37281b3b4bbe3221bda826ac6a9a62d6444cdb0dcd0615698a5cbe587c3f0fe57a54d8f5') { echo 'Installer verified'; } else { echo 'Installer corrupt'; unlink('composer-setup.php'); } echo PHP_EOL;"; \
	php composer-setup.php --install-dir=/usr/local/bin --filename=composer; \
	php -r "unlink('composer-setup.php');"

# Set permission owner for nginx
RUN chown -R www-data:www-data /var/www

VOLUME /var/www/app

CMD ["apache2-foreground"]