This is a very large refactoring which aims at making Tutor both more
extendable and more generic. Historically, the Tutor plugin system was
designed as an ad-hoc solution to allow developers to modify their own
Open edX platforms without having to fork Tutor. The plugin API was
simple, but limited, because of its ad-hoc nature. As a consequence,
there were many things that plugin developers could not do, such as
extending different parts of the CLI or adding custom template filters.
Here, we refactor the whole codebase to make use of a generic plugin
system. This system was inspired by the Wordpress plugin API and the
Open edX "hooks and filters" API. The various components are added to a
small core thanks to a set of actions and filters. Actions are callback
functions that can be triggered at different points of the application
lifecycle. Filters are functions that modify some data. Both actions and
filters are collectively named as "hooks". Hooks can optionally be
created within a certain context, which makes it easier to keep track of
which application created which callback.
This new hooks system allows us to provide a Python API that developers
can use to extend their applications. The API reference is added to the
documentation, along with a new plugin development tutorial.
The plugin v0 API remains supported for backward compatibility of
existing plugins.
Done:
- Do not load commands from plugins which are not enabled.
- Load enabled plugins once on start.
- Implement contexts for actions and filters, which allow us to keep track of
the source of every hook.
- Migrate patches
- Migrate commands
- Migrate plugin detection
- Migrate templates_root
- Migrate config
- Migrate template environment globals and filters
- Migrate hooks to tasks
- Generate hook documentation
- Generate patch reference documentation
- Add the concept of action priority
Close #499.
`upgrade` had several issues, which are summarized here:
https://discuss.overhang.io/t/confusing-instructions-during-upgrade/2281/7
- The docs say that you should run quickstart, but what most people will see is
the big command tutor local upgrade --from=lilac verbatim paragraph.
- The local upgrade command should be very explicit about the fact that users
need to run quickstart.
- Maybe the name of the local upgrade command should be improved.
- When upgrading tutor from one major release to the next, there should be a
more explicit warning to inform users of what they are doing (see this other
conversation 1)
- We should tell people that they almost certainly need to enable the tutor and
the mfe plugins, if they are not enabled during upgrade.
- A link to all of the breaking changes from the changelog should be
prominently displayed during upgrade.
- The docs should emphasize that upgrading from one major release to the next
is potentially a risky endeavor and that downgrading is not possible. The docs
should also link to the changelog.
This commit has grown slightly beyond the intended scope, but the changes should be mostly positive.
Previously, configuration management was very confusing because we kept mixing
"base" and "defaults" configuration:
- It was difficult to make the difference between core settings that were
necessary (e.g: passwords) as opposed to others that could simply be
defaulted to.
- The order of settings in config.yml mattered: config entries that depended on
other needed to be defined later. As a consequence, Tutor was not compatible
with Python 3.5, where dict entries are not sorted.
We were forced to pin click to < v8 because of missing dependencies. In
particular, click_repl was broken. This is no longer the case, as click_repl
0.20 was published. Also, Jinja2 now includes type annotations, which allows us
to get rid of a few "# type: ignore" statements.
We take the opportunity to upgrade all requirements, which allows us resolve a
security issue on urllib3<1.26.0.
I stumbled upon a bug that should have been detected by the type
checking. Turns out, considering that config is of type Dict[str, Any]
means that we can use just any method on all config values -- which is
terrible. I discovered this after I set `config["PLUGINS"] = None`:
this triggered a crash when I enabled a plugin.
We resolve this by making the Config type more explicit. We also take
the opportunity to remove a few cast statements.
Annotations were generated with pyannotate:
https://github.com/dropbox/pyannotate
We are running in strict mode, which is awesome!
This affects a large part of the code base, which might be an issue for
people running a fork of Tutor. Nonetheless, the behavior should not be
affected. If anything, this process has helped find and resolve a few
type-related bugs. Thus, this is not considered as a breaking change.
- 💥[Improvement] Upgrade Open edX to Koa
- 💥 Setting changes:
- The ``ACTIVATE_HTTPS`` setting was renamed to ``ENABLE_HTTPS``.
- Other ``ACTIVATE_*`` variables were all renamed to ``RUN_*``.
- The ``WEB_PROXY`` setting was removed and ``RUN_CADDY`` was added.
- The ``NGINX_HTTPS_PORT`` setting is deprecated.
- Architectural changes:
- Use Caddy as a web proxy for automated SSL/TLS certificate generation:
- Nginx no longer listens to port 443 for https traffic
- The Caddy configuration file comes with a new ``caddyfile`` patch for much simpler SSL/TLS management.
- Configuration files for web proxies are no longer provided.
- Kubernetes deployment no longer requires setting up a custom Ingress resource or custom manager.
- Gunicorn and Whitenoise are replaced by uwsgi: this increases boostrap performance and makes it no longer necessary to mount media folders in the Nginx container.
- Replace memcached and rabbitmq by redis.
- Additional features:
- Make it possible to disable all plugins at once with ``plugins disable all``.
- Add ``tutor k8s wait`` command to wait for a pod to become ready
- Faster, more reliable static assets with local memory caching
- Deprecation: proxy files for Apache and Nginx are no longer provided out of the box.
- Removed plugin `{{ patch (...) }}` statements:
- "https-create", "k8s-ingress-rules", "k8s-ingress-tls-hosts": these are no longer necessary. Instead, declare your app in the "caddyfile" patch.
- "local-docker-compose-nginx-volumes": this patch was primarily used to serve media assets. The recommended is now to serve assets with uwsgi.
Here, we upgrade the Open edX platform from Ironwood to Juniper. This
upgrade does not come with many feature changes, but there are many
technical improvements under the hood:
- Upgrade from Python 2.7 to 3.5
- Upgrade from Mongodb v3.2 to v3.6
- Upgrade Ruby to 2.5.7
We took the opportunity to completely rething the way locally running
platforms should be accessed for testing purposes. It is no longer
possible to access a running platform from http://localhost and
http://studio.localhost. Instead, users should access
http://local.overhang.io and https://studio.local.overhang.io. This
drastically simplifies internal communication between Docker containers.
To upgrade, users should simply run:
tutor local quickstart
For Kubernetes platform, the upgrade process is outlined when running:
tutor k8s upgrade --from=ironwood
Clarify a few variable names, make code more modular. Also, the Renderer
class now makes more sense as a singleton. We took the opportunity to
delete quite a lot of code.
This has an impact on plugin hooks. Plugin hooks that needed to run
inside mysql-client now need to run inside mysql container. This
simplifies the deployment, as we no longer have an empty mysql-client
container sitting around.
When mysql is not enabled (ACTIVATE_MYSQL=False) the mysql container is
simply a mysql client.
This commit introduces many changes:
- a fully functional minio plugin for local installation
- an almost-functional native k8s deployment
- a new way to process configuration, better suited to plugins
There are still many things to do:
- get rid of all the TODOs
- get a fully functional minio plugin for k8s
- add documentation for pluginso
- ...
Configuration loading was overly complex. Here, we simplify it
drastically with reasonable defaults. Hacky additional variables are
unncessary now that we use custom jinja2 filters.
Régis Behmo
alex.soh