Comment 1 for bug 1895201

Reviewed: https://reviews.mahara.org/11209
Committed: https://git.mahara.org/mahara/mahara/commit/87e202ef3cf55365fb42e285962c6f4e16bbfc7f
Submitter: Cecilia Vela Gurovic (<email address hidden>)
Branch: master

commit 87e202ef3cf55365fb42e285962c6f4e16bbfc7f
Author: Glenn Walbran <email address hidden>
Date: Mon Aug 17 14:30:47 2020 +1200

Bug 1895201 Docker images for Mahara

This commit adds docker images for building, testing and running Mahara.
The images are:
- mahara-base, has packages that are needed to both run and test Mahara.
Base of an ubuntu base image.
- mahara-builder, image to be used for building and testing Mahara. Extends
mahara-base and adds packages needed for building and testing
- mahara, image used for running Mahara. Has the Mahara code (that has
already been built) baked into it.

Things to note:
- The configuration in the docker images is driven by environment variables.
htdocs/config-environment.php is a config file variant that will look for
config in from the environment variables else fall back to a default value.
This file is copied to config.php as part of creating the mahara image.
- The mahara image only has support for http. If https is required (which is
recommended) then this should be done by adding a reverse proxy whose job
is to terminate the https.

Change-Id: I65af1231dc42684e596c6e236fcf1de166d1abc7