Tutor Analysis

This learnings from this analysis and others are being acted upon in a Tutor Adoption Initiative, which aims to make Tutor viable to fully replace for Devstack. Keep an eye on that project for the latest on Tutor enhancements & extensions.

Table of Contents

1 1 Overview
2 2 Rubric
3 3 Steps for Local Dev
4 4 Questions for Régis
5 5 Next Steps

1 Overview

An evaluation was made in March 2021 of the readiness of Tutor as a potential replacement of the Open edX devstack.

See https://openedx.atlassian.net/browse/ARCHBOM-1670

At this time, Tutor has enough gaps that it is not yet ready. However, next steps were also documented.

2 Rubric

Capability	Tutor	Open edX Devstack

Capability	Tutor	Open edX Devstack
Make edx-platform code change and see it via runserver	Works	Works
Run Specific Unit Tests	Works	Works
Run Quality tests	Works	Works
Make discovery change and see it via runserver	Doesn't work missing ES7 related changes.	Works
Run discovery unit tests	N/A	Works
Make an MFE code change and see it in the browser	No MFE Plugins right now.	Some MFEs are supported but not all
Run MFE tests	N/A	Works
Make a backend config change	Works but has a tutor specific layer to it	Works but is complicated by ansible
Run MFE outside devstack/tutor	Works once all the relevant host names are updated	Works

3 Steps for Local Dev

Tests were done with the version of Tutor in this pr: fix: Only ignore warnings if they exist. by feanil · Pull Request #407 · overhangio/tutor

NOTE: Many steps will update the docker-compose.override.yml file. Here is what the final version looks like:

version: "3.7"
services:
  lms:
    volumes:
      - /home/feanil/src/edx-platform/:/openedx/edx-platform
      - /home/feanil/.local/share/tutor/volumes/edx-platform-venv/:/openedx/venv
  cms:
    volumes:
      - /home/feanil/src/edx-platform/:/openedx/edx-platform
      - /home/feanil/.local/share/tutor/volumes/edx-platform-venv/:/openedx/venv
  lms-worker:
    volumes:
      - /home/feanil/src/edx-platform/:/openedx/edx-platform
      - /home/feanil/.local/share/tutor/volumes/edx-platform-venv/:/openedx/venv
  cms-worker:
    volumes:
      - /home/feanil/src/edx-platform/:/openedx/edx-platform
      - /home/feanil/.local/share/tutor/volumes/edx-platform-venv/:/openedx/venv
  discovery:
    volumes:
      - /home/feanil/src/course-discovery/:/openedx/discovery
      - /home/feanil/.local/share/tutor/volumes/discovery-venv/:/openedx/venv

3.1 Steps for Setting up a branch version of Tutor

git clone git@github.com:feanil/tutor.git
cd tutor
git checkout feanil/more_resilient_warning_suppression
mkvirtualenv -p python3 tutor
pip install -e .

3.2 Setup to do edx-platform Dev

Setup for development per first section of https://docs.tutor.overhang.io/dev.html, summarized with the commands below:
tutor local quickstart tutor local stop tutor images build openedx-dev
Override source code mounts to point to local edx-platform code by following instructions in this section: https://docs.tutor.overhang.io/dev.html#override-docker-compose-volumes
- Note: See first line in each volumes section in example .yml file above.
Copy container’s venv to the host using the bindmount command.
tutor dev bindmount lms /openedx/venv cd $(tutor config printroot)/volumes mv venv edx-platform-venv
Update docker-compose overrides file to mount the local venv into the container.
vim "$(tutor config printroot)/env/dev/docker-compose.override.yml"
Add a line like the following to the override file for each of the containers (lms, cms, lms-worker, cms-worker)
/home/feanil/.local/share/tutor/volumes/edx-platform-venv/:/openedx/venv
tutor dev run lms pip install -r requirements/edx/development.txt
tutor dev run lms ./manage.py lms migrate
tutor dev runserver lms

3.3 Adding Discovery

The following instructions are not enough to get discovery working because we need to be using the ES7 images and update the settings file to inject the correct overrides into tutor to work with elasticsearch DSL. We did not proceed with that work at this point.

pip install tutor-discovery
tutor plugins enable discovery
Copy discovery container’s venv to the host using the bindmount command.
tutor dev bindmount discovery /openedx/venv cd $(tutor config printroot)/volumes mv venv discovery-venv
Update docker-compose.override.yml to add discovery service with local venv and discovery code.
version: "3.7" services: ... discovery: volumes: - /home/feanil/src/course-discovery/:/openedx/discovery - /home/feanil/.local/share/tutor/volumes/discovery-venv/:/openedx/venv

3.4 Running with an MFE next to tutor

Download MFE
Update .env.development
- Replace all occurances of localhost:18000 -> local.overhang.io:8000
- Replace localhost:1997 -> local.overhang.io:1997
Run webpack server manually to set host to local.overhang.io.
./node_modules/.bin/fedx-scripts webpack-dev-server –progress –env development –host local.overhang.io
Navigate to local.overhang.io:1997

4 Questions for Régis

After I update tutor/templates/apps/openedx/settings/partials/pre_common_all.py how do I update my local tutor settings files?
Why does the run command set permissions every time?
- Should we be running exec instead?
Why do we have to re-build the image between dev and test? https://docs.tutor.overhang.io/dev.html#running-edx-platform-unit-tests
- Could there be a simpler workflow?
Is setting up to test e2e something you're planning to do?
If we want to change Django settings, is this where we should be using some existing hooks that we're not aware of?
Why have your own Django settings files? Is this due to historic reasons?

5 Next Steps

Talk to Régis about our open questions. Include Adolfo in conversation.
Reevaluate in the future after some of the gaps have narrowed, or prioritize helping narrow the gaps. See the following notes on the current stance on various questions:
- Should we replace devstack with tutor today? No.
- Should we replace devstack with tutor someday? Maybe.
- What's preventing us from doing it now?
  - Missing MFEs
    - Currently Tutor has no MFE plugins. We would need to build this.
  - Missing Backend Plugins
    - Credentials
    - Registrar
  - Out of date with Master for data layer services (mongo, es)
    - Example: Course discovery elasticsearch
    - This may be tricky to fix and would involve updating tutor's settings files and default images.
      - Replacing default images is already supported.
      - We may be able to use hooks to update settings which is the other thing that would be needed.
  - Not all Unit Test work for the LMS
  - Other various use cases that devstack currently supports and Tutor doesn't (not making a value judgement, just calling out for completeness.)
    - e2e testing
    - Generating Programs Data
    - No quick script to provision all plugins at once, each service/plugin is manage individually.
      - Missing a "do all the things" script is fine if we want the users to know and do each thing they want manually.
      - But missing the "do all the things" scirpt does increase the number of things a developer needs to know and do manually.
    - The option to run with NFS mounts

Architecture and Engineering