notifications-template-preview

Generates PNG and PDF previews of letter templates created in the GOV.UK Notify admin app.

Setting Up

Docker container

This app uses dependencies that are difficult to install locally. In order to make local development easy, we run app commands through a Docker container. Run the following to set this up:

  make bootstrap-with-docker

Because the container caches things like Python packages, you will need to run this again if you change things like "requirements.txt".

AWS credentials

To run the app you will need appropriate AWS credentials. See the Wiki for more details.

environment.sh

In the root directory of the application, run:

echo "
export NOTIFICATION_QUEUE_PREFIX='YOUR_OWN_PREFIX'
"> environment.sh

Things to change:

• Replace YOUR_OWN_PREFIX with local_dev_<first name>.

uv

We use uv for Python dependency management. Follow the install instructions or run:

curl -LsSf https://astral.sh/uv/install.sh | sh

Pre-commit

We use pre-commit to ensure that committed code meets basic standards for formatting, and will make basic fixes for you to save time and aggravation.

Install pre-commit system-wide with, eg brew install pre-commit. Then, install the hooks in this repository with pre-commit install --install-hooks.

To test the application

make test-with-docker

If you need to run a specific command, such as a single test, you can use the run_with_docker.sh script. This is what test and other make rules use.

./scripts/run_with_docker.sh pytest tests/some_specific_test.py

To run the application

# run the web app
make run-flask-with-docker

Then visit your app at http://localhost:6013/.

# run the background tasks
make run-celery-with-docker

Celery is used for sanitising PDF letters asynchronously. It requires the NOTIFICATION_QUEUE_PREFIX environment variable to be set to the same value used in notifications-api.

Further documentation

• Making local requests
• Guidance for deploying changes
• The invisible "NOTIFY" tag
• Updating dependencies