Dockerfile

FROM php:7.2-apache

# install the PHP extensions we need
RUN set -ex; \
    \
    savedAptMark="$(apt-mark showmanual)"; \
    \
    apt-get update; \
    apt-get install -y --no-install-recommends \
        libjpeg-dev \
        libpng-dev \
    ; \
    \
    docker-php-ext-configure gd --with-png-dir=/usr --with-jpeg-dir=/usr; \
    docker-php-ext-install gd mysqli opcache; \
    \
# 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'; \
        echo 'opcache.enable_cli=1'; \
    } > /usr/local/etc/php/conf.d/opcache-recommended.ini

RUN a2enmod rewrite expires

# Add wp cli
RUN curl -o /usr/local/bin/wp -O https://raw.githubusercontent.com/wp-cli/builds/gh-pages/phar/wp-cli.phar && \
    chmod +x /usr/local/bin/wp

ENV WORDPRESS_VERSION 4.9.4
ENV WORDPRESS_SHA1 0e630bf940fd586b10e099cd9195b3e825fb194c

RUN set -ex; \
    curl -o wordpress.tar.gz -fSL "https://wordpress.org/wordpress-${WORDPRESS_VERSION}.tar.gz"; \
    echo "$WORDPRESS_SHA1 *wordpress.tar.gz" | sha1sum -c -; \
# upstream tarballs include ./wordpress/ so this gives us /var/www/wordpress
    tar -xzf wordpress.tar.gz -C /var/www/html --strip-components=1; \
    rm wordpress.tar.gz; \
    chown -R www-data:www-data /var/www/html

COPY docker-entrypoint.sh /usr/local/bin/

ADD --chown=www-data:www-data .htaccess /var/www/html/

ENTRYPOINT ["docker-entrypoint.sh"]
CMD ["apache2-foreground"]

# Add our custom content, basic theme in this sample
ADD --chown=www-data:www-data ./theme /var/www/html/wp-content/themes/my-theme