David McDonald ad274ee887 Set count_pages as False to stop running of redundant query
This is a similar PR to https://github.com/alphagov/notifications-api/pull/2284.

When using flask-sqlalchemy to get a `Pagination` object, by default
it will run two queries

1. Get the page of results that you are asking for
2. If the number of results is equal to the page size, then it will
  issue a second query that will count the total number of results

Getting the total number of results is only useful if
- you need to show how many results there are
- you need to know if there is a next page of results (flask-sqlalchemy
  uses the total to work out how many pages there are altogether,
  which may not be the most efficient way of working out if there
  is a next page or not but that is what it currently does).

Looking at the `get_notifications` route, it does
not use `paginated_notifications.total` or
`paginated_notifications.has_next` and therefore we have no use
for the second query to get the total number of results.

We can stop this additional query by setting `count_pages=False`
which will hopefully give us some performance improvements, in
particular for services which send a lot of notifications.

Flask sqlalchemy references:
818c947b66/src/flask_sqlalchemy/__init__.py (L478)
818c947b66/src/flask_sqlalchemy/__init__.py (L399)

Note, I have checked the other uses of `get_notifications_for_service`
and the other cases are currently using the total or next page so
this approach is not something we can take with them.
2021-12-01 16:51:05 +00:00
2021-11-11 13:54:21 +00:00
2021-03-08 17:44:48 +00:00
2021-11-18 15:43:39 +00:00
2021-11-18 15:43:39 +00:00
2021-11-11 13:54:14 +00:00

GOV.UK Notify API

Contains:

  • the public-facing REST API for GOV.UK Notify, which teams can integrate with using our clients
  • an internal-only REST API built using Flask to manage services, users, templates, etc (this is what the admin app talks to)
  • asynchronous workers built using Celery to put things on queues and read them off to be processed, sent to providers, updated, etc

Setting Up

Python version

We run python 3.9 both locally and in production.

pycurl

See https://github.com/alphagov/notifications-manuals/wiki/Getting-started#pycurl

AWS credentials

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

environment.sh

Creating and edit an environment.sh file.

echo "
export NOTIFY_ENVIRONMENT='development'

export MMG_API_KEY='MMG_API_KEY'
export FIRETEXT_API_KEY='FIRETEXT_ACTUAL_KEY'
export NOTIFICATION_QUEUE_PREFIX='YOUR_OWN_PREFIX'

export FLASK_APP=application.py
export FLASK_ENV=development
export WERKZEUG_DEBUG_PIN=off
"> environment.sh

Things to change:

  • Replace YOUR_OWN_PREFIX with local_dev_<first name>.
  • Run the following in the credentials repo to get the API keys.
notify-pass credentials/providers/api_keys

Postgres

Install Postgres.app.

Currently the API works with PostgreSQL 11. After installation, open the Postgres app, open the sidebar, and update or replace the default server with a compatible version.

Note: you may need to add the following directory to your PATH in order to bootstrap the app.

export PATH=${PATH}:/Applications/Postgres.app/Contents/Versions/11/bin/

Redis

To switch redis on you'll need to install it locally. On a OSX we've used brew for this. To use redis caching you need to switch it on by changing the config for development:

    REDIS_ENABLED = True

To run the application

# install dependencies, etc.
make bootstrap

# run the web app
make run-flask

# run the background tasks
make run-celery

# run scheduled tasks (optional)
make run-celery-beat

To test the application

# install dependencies, etc.
make bootstrap

make test

To update application dependencies

To update application dependencies

requirements.txt is generated from the requirements.in in order to pin versions of all nested dependencies. If requirements.in has been changed, run make freeze-requirements to regenerate it.

To run one off tasks

Tasks are run through the flask command - run flask --help for more information. There are two sections we need to care about: flask db contains alembic migration commands, and flask command contains all of our custom commands. For example, to purge all dynamically generated functional test data, do the following:

Locally

flask command purge_functional_test_data -u <functional tests user name prefix>

On the server

cf run-task notify-api "flask command purge_functional_test_data -u <functional tests user name prefix>"

All commands and command options have a --help command if you need more information.

Further documentation

Description
The API powering Notify.gov
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