csua-backend

A backend for the CSUA interblags.

A Django web app that:

• Hosts our website at https://www.csua.berkeley.edu
  • Displays information about our club
  • Manages and displays current officers, politburo, sponsors, and events
  • Provides new CSUA account creation
  • Provides CSUA account password resets
  • Provides interface for managing LDAP groups
• Runs a slack bot on https://csua.slack.com
• Runs a discord bot on https://www.csua.berkeley.edu/discord
• Tracks Soda 311 office computer usage

See issues for a list of TODOs.

User Workflow

1. (Optional) Create a fork of this repo
   • Do this if you don't have write access
   • If you do have write access, use a new branch instead
2. Clone to your local/development machine
3. Install dependencies
4. Make changes, test, repeat
5. Commit those changes
6. Push commits to your fork/branch
7. Make a pull request

Installation (venv, manual)

1. Install Python 3.9+
2. Create venv python3 -m venv venv
3. Install Django and dependencies with venv/bin/pip3 install -r requirements.txt
4. Install pre-commit with venv/bin/pre-commit install
5. Create your .env file by copying .env.dev, e.g. cp .env.dev .env
6. Set up local sqlite database with venv/bin/python3 manage.py migrate
7. Run server with venv/bin/python3 manage.py runserver

• If on soda, you will have to run venv/bin/python3 manage.py runserver 0.0.0.0:$PORT where $PORT is between 8000 and 8999, and connect by going to http://soda.berkeley.edu:$PORT

7. Navigate web browser to http://127.0.0.1:8000/
8. Create admin user with venv/bin/python3 manage.py createsuperuser
   • Visit the admin page at http://127.0.0.1:8000/admin/ to add a semester object

Installation (venv, automatic)

If you're using GNU/Linux or OSX, use bootstrap.sh.

pre-commit and black

pre-commit is a tool that picks up formatting and other issues before making a commit. It will automatically format your python code with black. This is so that the code is clean and consistent, making it easier to review.

Additionally, I recommend you set up autoformatting with black on-save. If you use vim, you can add this to your .vimrc:

autocmd BufWritePost *.py silent exec "!black <afile>" | exec "redraw!"

Making changes to database models

1. Make changes to db_data/models.py
2. venv/bin/python3 manage.py makemigrations on your development machine
3. venv/bin/python3 manage.py migrate to apply new migrations to your local db
4. Commit and push your changes to models.py as well as generated migrations/
5. Pull latest changes on remote machine
6. python3 manage.py migrate on remote machine to update database with latest models
7. Run sudo systemctl reload csua-backend-gunicorn on the remote machine so the changes take effect

Editing/Creating/Deleting Data

Go to https://www.csua.berkeley.edu/admin/ to edit data!

Repo structure

Django's online documentation has more detail on a project's structure

• apps/
  • This Django project is divided into "apps" (i.e. main_page/, db_data/, etc.)
  • csua_backend/ holds the projects's configurations
  • Each app is divided into:
    • migrations/ lists the changes that have been made to the database models
    • __init__.py just tells python the app is a python module
    • admin.py details how db models should be viewed in the admin interface
    • apps.py probably says that this directory is an app
    • models.py contains the database models of the app
    • tests.py has unit tests to test the apps functionality
    • urls.py says what URLs route to which views
    • views.py has functions that serve a "view" (webpage)
• fixtures/ contains database fixtures to record and bootstrap content and various database data
• media_root/ is where user-uploaded files are served from
• requirements.txt lists the required python packages for this project.
• static_root/ is where static files are served from (many of which come from ./static/ and are moved here by manage.py's collectstatic)
• templates/ holds the html templates that are populated and served by views
• manage.py is a command-line script for performing actions on the project

Deploying

As of 2024 we no longer use Travis CI (our repo was formerly located here). Please manually deploy from Tap instead:

Manual Deploy

1. ssh into tap.csua.berkeley.edu
2. Change directory to the project directory /webserver/csua-backend/
3. sudo -u www-data git pull
4. sudo -u www-data venv/bin/python manage.py collectstatic to update static files
5. sudo -u www-data venv/bin/python manage.py migrate to migrate db
6. sudo -u www-data venv/bin/python manage.py test to make sure tests pass
7. sudo systemctl restart csua-backend-gunicorn to restart server

Deployment Details

• This Django app runs as a wsgi app on a gunicorn server on tap.
• The gunicorn process is managed by systemd and the service file is located at /etc/systemd/system/csua-backend-gunicorn.service
  • This service can be manipulated with systemctl
    • To reload the wsgi app, run sudo systemctl reload csua-backend-gunicorn
• tap runs debian 9.8 (stretch), we are using Python 3.9.
• The app is behind an Nginx proxy.
  • Nginx serves the static and media files, homedirs, and forwards all other requests to the app.
  • https://github.com/CSUA/services-nginx/blob/master/sites-available/www.csua.berkeley.edu
  • /etc/nginx/sites-available/www.csua.berkeley.edu
• mysqlclient is installed and necessary for deployment on tap

/etc/sudoers

These changes are here so that the newuser script and deployment script run properly. If the change, /etc/sudoers may also need to be changed.

www-data ALL = (root) NOPASSWD: /webserver/csua-backend/apps/newuser/config_newuser
www-data ALL = NOPASSWD: /bin/systemctl restart csua-backend-gunicorn

LDAP Details

tap runs an OpenLDAP server. It is accessible from anywhere over TLS on port 636.

For an LDAP client to connect, it must accept our self-signed certificate. Usually this is done by adding this line to /etc/ldap/ldap.conf:

TLS_REQCERT allow

Dumping database data into json:

python3 manage.py dumpdata db_data > fixtures/$(date +db_data-%m%d%y.json)