diff --git a/.travis.yml b/.travis.yml
index d7e2048..fec49af 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -3,16 +3,16 @@ services: docker
 
 env:
   - VARIANT=php5.6/apache
-  - VARIANT=php7.0/apache
-  - VARIANT=php7.1/apache
-  - VARIANT=php7.2/apache
   - VARIANT=php5.6/fpm
-  - VARIANT=php7.0/fpm
-  - VARIANT=php7.1/fpm
-  - VARIANT=php7.2/fpm
   - VARIANT=php5.6/fpm-alpine
+  - VARIANT=php7.0/apache
+  - VARIANT=php7.0/fpm
   - VARIANT=php7.0/fpm-alpine
+  - VARIANT=php7.1/apache
+  - VARIANT=php7.1/fpm
   - VARIANT=php7.1/fpm-alpine
+  - VARIANT=php7.2/apache
+  - VARIANT=php7.2/fpm
   - VARIANT=php7.2/fpm-alpine
 
 install:
diff --git a/Dockerfile-alpine.template b/Dockerfile-alpine.template
new file mode 100644
index 0000000..2f1de78
--- /dev/null
+++ b/Dockerfile-alpine.template
@@ -0,0 +1,80 @@
+FROM php:%%PHP_VERSION%%-%%VARIANT%%
+LABEL maintainer="Michael Babker <michael.babker@joomla.org> (@mbabker)"
+
+# Disable remote database security requirements.
+ENV JOOMLA_INSTALLATION_DISABLE_LOCALHOST_CHECK=1
+
+# entrypoint.sh dependencies
+RUN apk add --no-cache \
+	bash
+
+# Install PHP extensions
+RUN set -ex; \
+	\
+	apk add --no-cache --virtual .build-deps \
+		$PHPIZE_DEPS \
+		autoconf \
+		bzip2-dev \
+		libjpeg-turbo-dev \
+		libmcrypt-dev \
+		libmemcached-dev \
+		libpng-dev \
+		openldap-dev \
+		pcre-dev \
+		postgresql-dev \
+	; \
+	\
+	docker-php-ext-configure gd --with-png-dir=/usr --with-jpeg-dir=/usr; \
+	docker-php-ext-configure ldap; \
+	docker-php-ext-install \
+		bz2 \
+		gd \
+		ldap \
+		mcrypt \
+		mysqli \
+		pdo_mysql \
+		pdo_pgsql \
+		pgsql \
+		zip \
+	; \
+	\
+# pecl will claim success even if one install fails, so we need to perform each install separately
+	pecl install APCu-%%APCU_VERSION%%; \
+	pecl install memcached-%%MEMCACHED_VERSION%%; \
+	pecl install redis-%%REDIS_VERSION%%; \
+	\
+	docker-php-ext-enable \
+		apcu \
+		memcached \
+		redis \
+	; \
+	\
+	runDeps="$( \
+		scanelf --needed --nobanner --format '%n#p' --recursive /usr/local/lib/php/extensions \
+		| tr ',' '\n' \
+		| sort -u \
+		| awk 'system("[ -e /usr/local/lib/" $1 " ]") == 0 { next } { print "so:" $1 }' \
+		)"; \
+	apk add --virtual .joomla-phpext-rundeps $runDeps; \
+	apk del .build-deps
+
+VOLUME /var/www/html
+
+# Define Joomla version and expected SHA1 signature
+ENV JOOMLA_VERSION %%VERSION%%
+ENV JOOMLA_SHA1 %%SHA1%%
+
+# Download package and extract to web volume
+RUN curl -o joomla.tar.bz2 -SL https://github.com/joomla/joomla-cms/releases/download/${JOOMLA_VERSION}/Joomla_${JOOMLA_VERSION}-Stable-Full_Package.tar.bz2 \
+	&& echo "$JOOMLA_SHA1 *joomla.tar.bz2" | sha1sum -c - \
+	&& mkdir /usr/src/joomla \
+	&& tar -xf joomla.tar.bz2 -C /usr/src/joomla \
+	&& rm joomla.tar.bz2 \
+	&& chown -R www-data:www-data /usr/src/joomla
+
+# Copy init scripts and custom .htaccess
+COPY docker-entrypoint.sh /entrypoint.sh
+COPY makedb.php /makedb.php
+
+ENTRYPOINT ["/entrypoint.sh"]
+CMD ["%%CMD%%"]
diff --git a/Dockerfile-debian.template b/Dockerfile-debian.template
new file mode 100644
index 0000000..924e12a
--- /dev/null
+++ b/Dockerfile-debian.template
@@ -0,0 +1,82 @@
+FROM php:%%PHP_VERSION%%-%%VARIANT%%
+LABEL maintainer="Michael Babker <michael.babker@joomla.org> (@mbabker)"
+
+# Disable remote database security requirements.
+ENV JOOMLA_INSTALLATION_DISABLE_LOCALHOST_CHECK=1
+%%VARIANT_EXTRAS%%
+# Install PHP extensions
+RUN set -ex; \
+	\
+	savedAptMark="$(apt-mark showmanual)"; \
+	\
+	apt-get update; \
+	apt-get install -y --no-install-recommends \
+		libbz2-dev \
+		libjpeg-dev \
+		libldap2-dev \
+		libmcrypt-dev \
+		libmemcached-dev \
+		libpng-dev \
+		libpq-dev \
+	; \
+	\
+	docker-php-ext-configure gd --with-png-dir=/usr --with-jpeg-dir=/usr; \
+	debMultiarch="$(dpkg-architecture --query DEB_BUILD_MULTIARCH)"; \
+	docker-php-ext-configure ldap --with-libdir="lib/$debMultiarch"; \
+	docker-php-ext-install \
+		bz2 \
+		gd \
+		ldap \
+		mcrypt \
+		mysqli \
+		pdo_mysql \
+		pdo_pgsql \
+		pgsql \
+		zip \
+	; \
+	\
+# pecl will claim success even if one install fails, so we need to perform each install separately
+	pecl install APCu-%%APCU_VERSION%%; \
+	pecl install memcached-%%MEMCACHED_VERSION%%; \
+	pecl install redis-%%REDIS_VERSION%%; \
+	\
+	docker-php-ext-enable \
+		apcu \
+		memcached \
+		redis \
+	; \
+	\
+# 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 $3 }' \
+		| sort -u \
+		| xargs -r dpkg-query -S \
+		| cut -d: -f1 \
+		| sort -u \
+		| xargs -rt apt-mark manual; \
+	\
+	apt-get purge -y --auto-remove -o APT::AutoRemove::RecommendsImportant=false; \
+	rm -rf /var/lib/apt/lists/*
+
+VOLUME /var/www/html
+
+# Define Joomla version and expected SHA1 signature
+ENV JOOMLA_VERSION %%VERSION%%
+ENV JOOMLA_SHA1 %%SHA1%%
+
+# Download package and extract to web volume
+RUN curl -o joomla.tar.bz2 -SL https://github.com/joomla/joomla-cms/releases/download/${JOOMLA_VERSION}/Joomla_${JOOMLA_VERSION}-Stable-Full_Package.tar.bz2 \
+	&& echo "$JOOMLA_SHA1 *joomla.tar.bz2" | sha1sum -c - \
+	&& mkdir /usr/src/joomla \
+	&& tar -xf joomla.tar.bz2 -C /usr/src/joomla \
+	&& rm joomla.tar.bz2 \
+	&& chown -R www-data:www-data /usr/src/joomla
+
+# Copy init scripts and custom .htaccess
+COPY docker-entrypoint.sh /entrypoint.sh
+COPY makedb.php /makedb.php
+
+ENTRYPOINT ["/entrypoint.sh"]
+CMD ["%%CMD%%"]
diff --git a/php5.6/fpm-alpine/Dockerfile b/php5.6/fpm-alpine/Dockerfile
index b757828..dee9307 100644
--- a/php5.6/fpm-alpine/Dockerfile
+++ b/php5.6/fpm-alpine/Dockerfile
@@ -12,13 +12,13 @@ RUN apk add --no-cache \
 RUN set -ex; \
 	\
 	apk add --no-cache --virtual .build-deps \
-		alpine-sdk \
+		$PHPIZE_DEPS \
 		autoconf \
 		bzip2-dev \
 		libjpeg-turbo-dev \
 		libmcrypt-dev \
-		libpng-dev \
 		libmemcached-dev \
+		libpng-dev \
 		openldap-dev \
 		pcre-dev \
 		postgresql-dev \
diff --git a/php7.0/fpm-alpine/Dockerfile b/php7.0/fpm-alpine/Dockerfile
index 04b8b73..95aef81 100644
--- a/php7.0/fpm-alpine/Dockerfile
+++ b/php7.0/fpm-alpine/Dockerfile
@@ -12,13 +12,13 @@ RUN apk add --no-cache \
 RUN set -ex; \
 	\
 	apk add --no-cache --virtual .build-deps \
-		alpine-sdk \
+		$PHPIZE_DEPS \
 		autoconf \
 		bzip2-dev \
 		libjpeg-turbo-dev \
 		libmcrypt-dev \
-		libpng-dev \
 		libmemcached-dev \
+		libpng-dev \
 		openldap-dev \
 		pcre-dev \
 		postgresql-dev \
diff --git a/php7.1/fpm-alpine/Dockerfile b/php7.1/fpm-alpine/Dockerfile
index 16f6497..26e5a80 100644
--- a/php7.1/fpm-alpine/Dockerfile
+++ b/php7.1/fpm-alpine/Dockerfile
@@ -12,13 +12,13 @@ RUN apk add --no-cache \
 RUN set -ex; \
 	\
 	apk add --no-cache --virtual .build-deps \
-		alpine-sdk \
+		$PHPIZE_DEPS \
 		autoconf \
 		bzip2-dev \
 		libjpeg-turbo-dev \
 		libmcrypt-dev \
-		libpng-dev \
 		libmemcached-dev \
+		libpng-dev \
 		openldap-dev \
 		pcre-dev \
 		postgresql-dev \
diff --git a/php7.2/fpm-alpine/Dockerfile b/php7.2/fpm-alpine/Dockerfile
index bce3438..c9a1eb2 100644
--- a/php7.2/fpm-alpine/Dockerfile
+++ b/php7.2/fpm-alpine/Dockerfile
@@ -12,12 +12,12 @@ RUN apk add --no-cache \
 RUN set -ex; \
 	\
 	apk add --no-cache --virtual .build-deps \
-		alpine-sdk \
+		$PHPIZE_DEPS \
 		autoconf \
 		bzip2-dev \
 		libjpeg-turbo-dev \
-		libpng-dev \
 		libmemcached-dev \
+		libpng-dev \
 		openldap-dev \
 		pcre-dev \
 		postgresql-dev \
diff --git a/update.php b/update.php
deleted file mode 100644
index b03c78c..0000000
--- a/update.php
+++ /dev/null
@@ -1,106 +0,0 @@
-<?php
-
-// Fetch the current 3.x version from the downloads site API
-$ch = curl_init();
-
-curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
-curl_setopt($ch, CURLOPT_URL, 'https://downloads.joomla.org/api/v1/latest/cms');
-
-$result = curl_exec($ch);
-
-curl_close($ch);
-
-if ($result === false)
-{
-	echo 'Could not fetch version data, please check your connection.' . PHP_EOL;
-
-	exit(1);
-}
-
-$data = json_decode($result, true);
-
-foreach ($data['branches'] as $branch)
-{
-	if ($branch['branch'] === 'Joomla! 3')
-	{
-		$version = $branch['version'];
-	}
-}
-
-if (!isset($version))
-{
-	echo 'Joomla! 3.x version data not included in API response.' . PHP_EOL;
-
-	exit(1);
-}
-
-$urlVersion = str_replace('.', '-', $version);
-
-$filename = "Joomla_$version-Stable-Full_Package.tar.bz2";
-
-// Fetch the SHA1 signature for the file
-$ch = curl_init();
-
-curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, false);
-curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
-curl_setopt($ch, CURLOPT_URL, "https://downloads.joomla.org/api/v1/signatures/cms/$urlVersion");
-
-$result = curl_exec($ch);
-
-curl_close($ch);
-
-if ($result === false)
-{
-	echo 'Could not fetch signature data, please check your connection.' . PHP_EOL;
-
-	exit(1);
-}
-
-$data = json_decode($result, true);
-
-foreach ($data['files'] as $file)
-{
-	if ($file['filename'] === $filename)
-	{
-		$signature = $file['sha1'];
-	}
-}
-
-if (!isset($signature))
-{
-	echo 'tar.bz2 file SHA1 signature not included in API response.' . PHP_EOL;
-
-	exit(1);
-}
-
-$phpVersions = [];
-$platforms   = ['apache', 'fpm', 'fpm-alpine'];
-
-/** @var DirectoryIterator $dir */
-foreach (new DirectoryIterator(__DIR__) as $dir)
-{
-	if (substr($dir->getFilename(), 0, 3) === 'php')
-	{
-		$phpVersions[] = $dir->getFilename();
-	}
-}
-
-foreach ($phpVersions as $phpVersion)
-{
-	foreach ($platforms as $platform)
-	{
-		$dockerfile = __DIR__ . "/$phpVersion/$platform/Dockerfile";
-
-		$fileContents = file_get_contents($dockerfile);
-		$fileContents = preg_replace('#ENV JOOMLA_VERSION [^ ]*\n#', "ENV JOOMLA_VERSION $version\n", $fileContents);
-		$fileContents = preg_replace('#ENV JOOMLA_SHA1 [^ ]*\n#', "ENV JOOMLA_SHA1 $signature\n\n", $fileContents);
-
-		file_put_contents($dockerfile, $fileContents);
-
-		// To make management easier, we use these files for all variants
-		copy(__DIR__ . '/docker-entrypoint.sh', __DIR__ . "/$phpVersion/$platform/docker-entrypoint.sh");
-		copy(__DIR__ . '/makedb.php', __DIR__ . "/$phpVersion/$platform/makedb.php");
-	}
-}
-
-echo 'Dockerfile variants updated' . PHP_EOL;
diff --git a/update.sh b/update.sh
new file mode 100755
index 0000000..3a49fbc
--- /dev/null
+++ b/update.sh
@@ -0,0 +1,87 @@
+#!/bin/bash
+set -euo pipefail
+
+cd "$(dirname "$(readlink -f "$BASH_SOURCE")")"
+
+phpVersions=( "$@" )
+if [ ${#phpVersions[@]} -eq 0 ]; then
+	phpVersions=( php*.*/ )
+fi
+phpVersions=( "${phpVersions[@]%/}" )
+
+current="$(curl -fsSL 'https://downloads.joomla.org/api/v1/latest/cms' | jq -r '.branches[3].version')"
+urlVersion=$(echo $current | sed -e 's/\./-/g')
+sha1="$(curl -fsSL "https://downloads.joomla.org/api/v1/signatures/cms/$urlVersion"  | jq -r --arg file "Joomla_${current}-Stable-Full_Package.tar.bz2" '.[] | .[] | select(.filename == $file).sha1')"
+
+declare -A variantExtras=(
+	[apache]='\n# Enable Apache Rewrite Module\nRUN a2enmod rewrite\n'
+	[fpm]=''
+	[fpm-alpine]=''
+)
+declare -A variantCmds=(
+	[apache]='apache2-foreground'
+	[fpm]='php-fpm'
+	[fpm-alpine]='php-fpm'
+)
+declare -A variantBases=(
+	[apache]='debian'
+	[fpm]='debian'
+	[fpm-alpine]='alpine'
+)
+declare -A pecl_versions=(
+	[php5-APCu]='4.0.11'
+	[php5-memcached]='2.2.0'
+	[php5-redis]='3.1.6'
+	[php7-APCu]='5.1.11'
+	[php7-memcached]='3.0.4'
+	[php7-redis]='3.1.6'
+)
+
+travisEnv=
+for phpVersion in "${phpVersions[@]}"; do
+	phpVersionDir="$phpVersion"
+	phpVersion="${phpVersion#php}"
+	phpMajorVersion=$(echo $phpVersionDir | cut -d. -f1)
+
+	for variant in apache fpm fpm-alpine; do
+		dir="$phpVersionDir/$variant"
+		mkdir -p "$dir"
+
+		extras="${variantExtras[$variant]}"
+		cmd="${variantCmds[$variant]}"
+		base="${variantBases[$variant]}"
+
+		entrypoint='docker-entrypoint.sh'
+
+		(
+			set -x
+
+			sed -r \
+				-e 's!%%VERSION%%!'"$current"'!g' \
+				-e 's!%%SHA1%%!'"$sha1"'!g' \
+				-e 's!%%PHP_VERSION%%!'"$phpVersion"'!g' \
+				-e 's!%%VARIANT%%!'"$variant"'!g' \
+				-e 's!%%VARIANT_EXTRAS%%!'"$extras"'!g' \
+				-e 's!%%APCU_VERSION%%!'"${pecl_versions[$phpMajorVersion-APCu]}"'!g' \
+				-e 's!%%MEMCACHED_VERSION%%!'"${pecl_versions[$phpMajorVersion-memcached]}"'!g' \
+				-e 's!%%REDIS_VERSION%%!'"${pecl_versions[$phpMajorVersion-redis]}"'!g' \
+				-e 's!%%CMD%%!'"$cmd"'!g' \
+				"Dockerfile-${base}.template" > "$dir/Dockerfile"
+
+			cp -a "$entrypoint" "$dir/docker-entrypoint.sh"
+			cp -a "makedb.php" "$dir/makedb.php"
+
+			if [ $phpVersionDir = "php7.2" ]; then
+				sed \
+					-e '/libmcrypt-dev/d' \
+					-e '/mcrypt/d' \
+					-i $dir/Dockerfile
+			fi
+		)
+
+		travisEnv+='\n  - VARIANT='"$dir"
+	done
+done
+
+travis="$(awk -v 'RS=\n\n' '$1 == "env:" { $0 = "env:'"$travisEnv"'" } { printf "%s%s", $0, RS }' .travis.yml)"
+echo "$travis" > .travis.yml