David McDonald 106187ba04 Fix division by zero error on performance page
For preview and staging environments, we often send no messages
in a single day. This is currently causing a `DivisionByZero` error
that is rendering the page with no results. This makes it impossible
to look at preview/staging and see if the performance page is
working correctly or not.

(psycopg2.errors.DivisionByZero) division by zero

[SQL: SELECT CAST(ft_processing_time.bst_date AS TEXT) AS date, ft_processing_time.messages_total AS ft_processing_time_messages_total, ft_processing_time.messages_within_10_secs AS ft_processing_time_messages_within_10_secs, (ft_processing_time.messages_within_10_secs / CAST(ft_processing_time.messages_total AS FLOAT)) * %(param_1)s AS percentage
FROM ft_processing_time
WHERE ft_processing_time.bst_date >= %(bst_date_1)s AND ft_processing_time.bst_date <= %(bst_date_2)s ORDER BY ft_processing_time.bst_date]
[parameters: {'param_1': 100, 'bst_date_1': datetime.date(2021, 11, 12), 'bst_date_2': datetime.date(2021, 11, 19)}]
(Background on this error at: http://sqlalche.me/e/14/9h9h)

I've fixed this by falling back to 100.0% for days we send
no messages. Maybe some argument that it should be N/A rather than
100% but I think it doesn't really matter as this is only
going to affect preview and staging as we will never have a day
sending no messages in production.
2021-11-22 11:11:52 +00:00
2020-05-12 16:04:18 +01:00
2019-08-02 12:41:03 +01:00
2021-11-11 13:54:21 +00:00
2021-03-08 17:44:48 +00:00
2021-11-15 11:12:33 +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
Readme 58 MiB
Languages
Python 98.5%
HCL 0.6%
Jinja 0.5%
Shell 0.3%
Makefile 0.1%