Dockerfile

ARG PHP_VERSION

FROM php:${PHP_VERSION}-fpm-alpine

ARG NEWRELIC_PHP_AGENT

# persistent dependencies
RUN set -eux; \
	apk add --no-cache \
# in theory, docker-entrypoint.sh is POSIX-compliant, but priority is a working, consistent image
		bash \
# Ghostscript is required for rendering PDF previews
		ghostscript \
# Alpine package for "imagemagick" contains ~120 .so files, see: https://github.com/docker-library/wordpress/pull/497
		imagemagick \
	;

# install the PHP extensions we need (https://make.wordpress.org/hosting/handbook/handbook/server-environment/#php-extensions)
# with redis, simplexml, soap
RUN set -ex; \
	\
	apk add --no-cache --virtual .build-deps \
		$PHPIZE_DEPS \
		freetype-dev \
		icu-dev \
		imagemagick-dev \
		libjpeg-turbo-dev \
		libpng-dev \
		libwebp-dev \
		libzip-dev \
        libxml2-dev \
	; \
	\
	docker-php-ext-configure gd \
		--with-freetype \
		--with-jpeg \
		--with-webp \
	; \
	docker-php-ext-install -j "$(nproc)" \
		bcmath \
		exif \
		gd \
		intl \
		mysqli \
		zip \
        simplexml \
        soap \
	; \
# WARNING: imagick is likely not supported on Alpine: https://github.com/Imagick/imagick/issues/328
# https://pecl.php.net/package/imagick
	pecl install imagick-3.6.0; \
	docker-php-ext-enable imagick; \
# https://pecl.php.net/package/redis \
    pecl install redis; \
    docker-php-ext-enable redis; \
	rm -r /tmp/pear; \
	\
# some misbehaving extensions end up outputting to stdout 🙈 (https://github.com/docker-library/wordpress/issues/669#issuecomment-993945967)
	out="$(php -r 'exit(0);')"; \
	[ -z "$out" ]; \
	err="$(php -r 'exit(0);' 3>&1 1>&2 2>&3)"; \
	[ -z "$err" ]; \
	\
	extDir="$(php -r 'echo ini_get("extension_dir");')"; \
	[ -d "$extDir" ]; \
	runDeps="$( \
		scanelf --needed --nobanner --format '%n#p' --recursive "$extDir" \
			| tr ',' '\n' \
			| sort -u \
			| awk 'system("[ -e /usr/local/lib/" $1 " ]") == 0 { next } { print "so:" $1 }' \
	)"; \
	apk add --no-network --virtual .wordpress-phpexts-rundeps $runDeps; \
	apk del --no-network .build-deps; \
	\
	! { ldd "$extDir"/*.so | grep 'not found'; }; \
# check for output like "PHP Warning:  PHP Startup: Unable to load dynamic library 'foo' (tried: ...)
	err="$(php --version 3>&1 1>&2 2>&3)"; \
	[ -z "$err" ]

# set recommended PHP.ini settings with tuning
# see https://www.php.net/manual/en/opcache.installation.php
RUN set -eux; \
	docker-php-ext-enable opcache; \
	{ \
		echo 'opcache.memory_consumption=128'; \
		echo 'opcache.interned_strings_buffer=8'; \
		echo 'opcache.max_accelerated_files=4000'; \
        echo 'opcache.validate_timestamps=0'; \
		echo 'opcache.revalidate_freq=0'; \
	} > /usr/local/etc/php/conf.d/opcache-recommended.ini
# https://wordpress.org/support/article/editing-wp-config-php/#configure-error-logging
RUN { \
# https://www.php.net/manual/en/errorfunc.constants.php
# https://github.com/docker-library/wordpress/issues/420#issuecomment-517839670
		echo 'error_reporting = E_ERROR | E_WARNING | E_PARSE | E_CORE_ERROR | E_CORE_WARNING | E_COMPILE_ERROR | E_COMPILE_WARNING | E_RECOVERABLE_ERROR'; \
		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

# set max upload size
RUN { \
        echo 'upload_max_filesize = 100M'; \
        echo 'post_max_size = 100M'; \
    } > /usr/local/etc/php/conf.d/uploads.ini

# install composer
COPY --from=composer:latest /usr/bin/composer /usr/local/bin/composer

# install wp-cli
RUN curl -o /usr/local/bin/wp https://raw.githubusercontent.com/wp-cli/builds/gh-pages/phar/wp-cli.phar \
    && chmod +x /usr/local/bin/wp
# allow wp-cli to be run as root
ENV WP_CLI_ALLOW_ROOT=1

# install New Relic
RUN set -eux; \
    apk add gcompat; \
    curl -o newrelic.tar.gz -L "https://download.newrelic.com/php_agent/archive/${NEWRELIC_PHP_AGENT}/newrelic-php5-${NEWRELIC_PHP_AGENT}-linux-musl.tar.gz"; \
    \
    tar -xzf newrelic.tar.gz -C /tmp; \
    rm newrelic.tar.gz; \
    \
    export NR_INSTALL_USE_CP_NOT_LN=1; \
    export NR_INSTALL_SILENT=1; \
    /tmp/newrelic-php5-*/newrelic-install install; \
    \
    rm -rf /tmp/newrelic-php5-*

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

ENTRYPOINT ["docker-entrypoint.sh"]
CMD ["php-fpm"]