Streamline the build of the image

This change makes it much faster to make smaller changes to the image
by:
- moving the ADD commands to more targeted additions in order of build
  size
- breaking out the Oracle and sqlsrv builds into their own ADD and RUN
  sections in the Dockerfile
- moving the addition of non build-related files to right at the end of
  the Dockerfile

These changes mean that it is possible to more easily developer the
image, for example:
- you can now make changes to files within the /usr directory without
  recompiling all PHP extensions
- you can now iterate on the Oracle and/or sqlsrv extensions without
  recompiling all PHP extensinos
- you can now iterate on the sqlsrv extension, without recompiling all
  PHP extensions

Whist this has little effect on the end image, or the build process
within CI systems, local development is substantially improved (unless
you're making changes to the php-extensions.sh script).

Dockerfile

@@ -5,10 +5,6 @@ ARG TARGETPLATFORM
 ENV TARGETPLATFORM=${TARGETPLATFORM:-linux/amd64}
 RUN echo "Building for ${TARGETPLATFORM}"
 
-ADD root/ /
-# Fix the original permissions of /tmp, the PHP default upload tmp dir.
-RUN chmod 777 /tmp && chmod +t /tmp
-
 # Install some packages that are useful within the images.
 RUN apt-get update && apt-get install -y \
     git \
@@ -30,11 +26,24 @@ RUN apt-get update && apt-get install -y \
 
 # Setup the required extensions.
 ARG DEBIAN_FRONTEND=noninteractive
+ADD root/tmp/setup/php-extensions.sh /tmp/setup/php-extensions.sh
 RUN /tmp/setup/php-extensions.sh
+
+# Install Oracle Instantclient
+ADD root/tmp/setup/oci8-extension.sh /tmp/setup/oci8-extension.sh
 RUN /tmp/setup/oci8-extension.sh
 ENV LD_LIBRARY_PATH /usr/local/instantclient
 
+# Install Microsoft sqlsrv.
+ADD root/tmp/setup/sqlsrv-extension.sh /tmp/setup/sqlsrv-extension.sh
+RUN /tmp/setup/sqlsrv-extension.sh
+
 RUN mkdir /var/www/moodledata && chown www-data /var/www/moodledata && \
     mkdir /var/www/phpunitdata && chown www-data /var/www/phpunitdata && \
     mkdir /var/www/behatdata && chown www-data /var/www/behatdata && \
     mkdir /var/www/behatfaildumps && chown www-data /var/www/behatfaildumps
+
+ADD root/usr /usr
+
+# Fix the original permissions of /tmp, the PHP default upload tmp dir.
+RUN chmod 777 /tmp && chmod +t /tmp

root/tmp/setup/php-extensions.sh

@@ -74,15 +74,6 @@ echo "pcov.exclude='~\/(tests|coverage|vendor|node_modules)\/~'" >> /usr/local/e
 echo "pcov.directory=." >> /usr/local/etc/php/conf.d/docker-php-ext-pcov.ini
 echo "pcov.initial.files=1024" >> /usr/local/etc/php/conf.d/docker-php-ext-pcov.ini
 
-# Install Microsoft dependencies for sqlsrv.
-# (kept apart for clarity, still need to be run here
-# before some build packages are deleted)
-if [[ ${TARGETPLATFORM} == "linux/amd64" ]]; then
-    /tmp/setup/sqlsrv-extension.sh
-else
-    echo "sqlsrv extension not available for ${TARGETPLATFORM} architecture, skipping"
-fi
-
 # Keep our image size down..
 pecl clear-cache
 apt-get remove --purge -y $BUILD_PACKAGES

root/tmp/setup/sqlsrv-extension.sh

@@ -2,6 +2,23 @@
 
 set -e
 
+if [[ ${TARGETPLATFORM} != "linux/amd64" ]]; then
+  echo "sqlsrv extension not available for ${TARGETPLATFORM} architecture, skipping"
+  exit 0
+fi
+
+# Packages for build.
+BUILD_PACKAGES="gnupg unixodbc-dev"
+
+# Packages for sqlsrv runtime.
+PACKAGES_SQLSRV=""
+
+echo "Installing apt dependencies"
+apt-get update
+apt-get install -y --no-install-recommends apt-transport-https \
+    $BUILD_PACKAGES \
+    $PACKAGES_SQLSRV
+
 # Install Microsoft dependencies for sqlsrv
 echo "Downloading sqlsrv files"
 curl https://packages.microsoft.com/keys/microsoft.asc | apt-key add -
@@ -17,3 +34,10 @@ ln -fsv /opt/mssql-tools/bin/* /usr/bin
 # Need 5.10.1 (or later) for PHP 8.2 support
 pecl install sqlsrv-5.10.1
 docker-php-ext-enable sqlsrv
+
+# Keep our image size down..
+pecl clear-cache
+apt-get remove --purge -y $BUILD_PACKAGES
+apt-get autoremove -y
+apt-get clean
+rm -rf /var/lib/apt/lists/*