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U.S. Press Freedom Tracker

This is the code that powers the U.S. Press Freedom Tracker website. It is built with Wagtail and served at pressfreedomtracker.us.

Development

Prerequisites

The installation instructions below assume you have the following software on your machine:

• docker
• docker compose

Local Development instructions

When you want to play with the environment, you will be using docker compose. Your guide to understand all the nuances of docker compose can be found in the official docs. To start the environment, run the following your first run:

# One-time command to run and forget
make dev-init

# Starts up the environment
docker compose up

# Inject development data (also only needs to be run once)
docker compose exec django ./manage.py createdevdata

# NOTE: temporarily not available due to incompatibility with wagtail 2.7
# Add wagtail inventory to search wagtail pages by block type
docker compose exec django ./manage.py block_inventory

You should be able to hit the web server interface by running make open-browser

If you run into any issues starting the application locally, check the troubleshooting doc for solutions to common problems.

Note: the createdevdata command fetches images from the internet by default. To disable this behavior, run the command with the --no-download argument, e.g.:

docker compose exec django ./manage.py createdevdata --no-download

To reset your database back to its initial state, I recommend removing the postgresql docker container and re-running the dev data command. First, stop your containers by pressing control+c if they are running. Then run these two commands.

docker compose rm -f postgresql && docker compose up --build
docker compose exec django ./manage.py createdevdata

To test your frontend code with jest, you can run the following command:

docker compose exec node npm test

If tests need to be updated, you can run the following command:

docker compose exec node npm test-update

Debugging

If you want to use the PDB program for debugging, it is possible. First, add this line to an area of the code you wish to debug:

import ipdb; ipdb.set_trace()

Second, attach to the running Django container. This must be done in a shell, and it is within this attached shell that you will be able to interact with the debugger. The command to attach is docker attach <ID_OF_DJANGO_CONTAINER>, and on UNIX-type systems, you can look up the ID and attach to the container with this single command:

docker attach $(docker compose ps -q django)

Once you have done this, you can load the page that will run the code with your import ipdb and the debugger will activate in the shell you attached. To detach from the shell without stopping the container press Control+P followed by Control+Q.

Debug Toolbar

Another debugging aid is the django debug toolbar It is disabled by default for performance reasons. To enable it, add

ENABLE_DEBUG_TOOLBAR = True

To tracker/settings/local.py (you may need to create this file if it does not exist in your local working copy). After reloading the page, there should be a tab in the upper-right corner of the page to open the toolbar.

Profiling

There are a couple of options preconfigured in this repo for profiling the application. They are django-cprofile-middleware, silk middleware, and pyinstrument.

Profiling is not enabled by default, as it does add potential performance overhead if you don't actively need it. To enable silk (and cprofile), set DJANGO_PROFILE=yes when starting docker compose. To enable pyinstrument, set PYINSTRUMENT=yes:

PYINSTRUMENT=yes DJANGO_PROFILE=yes docker compose up

This will enable both middlewares. To view the cProfile information for any url, append ?prof to the url (or add it to an existing query string with &prof). This can give you fairly detailed information about which lines of code are causing your view to be slow. Additional information about the information provided is available in the Python documentation.

Pyinstrument functions similarly to cProfile, but it has a much nicer interface. Append ?profile (or &profile) to any URL to load it.

If the specific lines of python code are not enough to determine what's causing the slowdown, it might be the database. To view more detailed profiling data about database queries, I recommend silk. The silk middleware logs all queries generated on a per-request basis. To see this, make a request to the view you want to profile, wait for it to complete, then load the silk admin at http://localhost:8000/silk.

Dependency Management

Adding new requirements

New requirements should be added to *requirements.in files, for use with pip-compile. There are two Python requirements files:

• requirements.in production application dependencies
• dev-requirements.in local testing and CI requirements

Add the desired dependency to the appropriate .in file, then run:

make compile-pip-dependencies

All requirements files will be regenerated based on compatible versions. Multiple .in files can be merged into a single .txt file, for use with pip. The Makefile target handles the merging of multiple files.

This process is the same if a requirement needs to be changed (i.e. its version number restricted) or removed. Make the appropriate change in the correct requirements.in file, then run the above command to compile the dependencies.

Upgrading existing requirements

There are separate commands to upgrade a package without changing the requirements.in files. The command

make pip-update PACKAGE=package-name

will update the package named package-name to the latest version allowed by the constraints in requirements.in and compile a new dev-requirements.txt and requirements.txt based on that version.

If the package appears only in dev-requirements.in, then you must use this command:

make pip-dev-update PACKAGE=package-name

which will update the package named package-name to the latest version allowed by the constraints in requirements.in and compile a new dev-requirements.txt.

Advanced actions against the database

Database import

Drop a postgres database dump into the root of the repo and rename it to import.db. To import it into a running dev session (ensure make dev-go has already been started) run make dev-import-db. Note that this will not pull in images that are referenced from an external site backup.

Connect to postgresql service from host

The postgresql service is exposed to your host on port 15432. If you have a GUI database manipulation application you'd like to utilize, your settings will be:

• username - tracker
• password - trackerpassword
• dbname - trackerdb
• the host/port can be determined by running docker compose port postgresql 5432

Mimic CI and production environment

You can mimic a production environment where django is deployment with gunicorn, reverse nginx proxy, and debug mode off using the following command:

docker compose -f prod-docker-compose.yaml up

All subsequent docker compose files will need that explicit -f flag pointing to the production-like compose file.

Database snapshots

When developing, it is often required to switch branches. These different branches can have mutually incompatible changes to the database, which can render the application inoperable. It is therefore helpful to be able to easily restore the database to a known-good state when making experimental changes. There are two commands provided to assist in this.

make dev-save-db: Saves a snapshot of the current state of the database to a file in the db-snapshots folder. This file is named for the currently checked-out git branch.

make dev-restore-db: Restores the most recent snapshot for the currently checked-out git branch. If none can be found, that is, make dev-save-db has never been run for the current branch, this command will do nothing. If a saved database is found, all data in database will be replaced with that from the file. Note that this command will terminate all connections to the database and delete all data there, so care is encouraged.

Workflow suggestions. I find it helpful to have one snapshot for each active branch I'm working on or reviewing, as well as for develop. Checking out a new branch and running its migrations should be followed by running make dev-save-db to give you a baseline to return to when needed.

When checking out a new branch after working on another, it can be helpful to restore your snapshot from develop, so that the migrations for the new branch, which were presumably based off of develop, will have a clean starting point.

Deployment

Important Note: We want to make PFT customizable for organizations who wish to deploy it as a tool for regions outside the US, but this work is still in progress. Please see #647 for the current status and how you can help.

Building

The development docker compose setup includes separate application and Node.js containers for hot-reloading purposes. To build a container for production use, run:

docker build --build-arg USERID=1000 -t TAG -f devops/docker/ProdDjangoDockerfile .

Running

This setup can also be tested locally with docker compose by using:

docker compose -f prod-docker-compose.yaml up

This setup will configure the app with production-like settings. In particular, whitenoise is used to serve static files.

Setup

When deploying the container to your actual production environment, refer to the environment variables in prod-docker-compose.yaml, changing things appropriately:

• DJANGO_DB_* for your database

• Based on your deployment domain/hostname:

  • DJANGO_BASE_URL
  • DJANGO_ALLOWED_HOSTS
  • DJANGO_CSRF_TRUSTED_ORIGINS
  • if applicable, DJANGO_ONION_HOSTNAME

• If you are using a read-only filesystem, give these a path to a read-write tmpfs:

  • DJANGO_GCORN_HEARTBT_DIR
  • DJANGO_GCORN_UPLOAD_DIR
  • TMPDIR

• Replace these dummied out secrets:

  • DJANGO_SECRET_KEY (generate a random one)
  • RECAPTCHA_*

• Using an object storage service for media files is recommended; for Google Storage:

  • GS_BUCKET_NAME
  • GS_CREDENTIALS (path to a JSON file)
  • GS_CUSTOM_ENDPOINT (if you have a CNAME pointing to your bucket)

This list is incomplete; please open an issues if you run into something missing.

Adobe Font Licenses

Licenses for Source Serif Pro and Source Sans Pro are available at the paths below.

• common/static/fonts/LICENSE.SourceSansPro.txt
• common/static/fonts/LICENSE.SourceSerifPro.txt

Design decision notes

Search

The search bar on the site is a shortcut to using incident search. This is because the site is primarily incident-related, and using incident search provides more powerful filtering as well as enhanced previews. As a result, there is no generic wagtail search view which includes other content such as blog posts. See #592.