dojo-monthly-emailer

the little bird that spurred the cat herd

How it works

zappa is a Python library that facilitates serverless web apps on AWS lambda.

We use zappa to set up an AWS lambda function accessable via an API Gateway URL. The function sends a reminder email anytime it's called on a Tuesday before the last Thursday of the month.

This is triggered by an IFTTT applet once a day:

We use pynt for a few "build" commands. Run pynt -l (and read build.py) to see available commands. You'll need to: pip install .[build].

Manual testing

The API Gateway URL, can also be used for manual testing. Running a deploy/update will notify you of this URL, and we can store it in the dojo organiser spreadsheet for reference.

Add ?force=1 to send a reminder email regardless of date.

Manual steps for deploying on a new AWS account

• zappa copies Python requirements directly from the active virtualenv

• so make an env, but note any random stuff you also install, gets uploaded too!

  • mkvirtualenv dojo-emailer

• install code and requirements

  • pip install -e .

• you may also like to install the test & build reqs via:

  • pip install .[test,build]

• setup local AWS credentials, perhaps with

  • pip install awscli
  • aws configure

• add discuss@ldnpydojo-org-uk as an AWS SES verified email

  • https://eu-west-1.console.aws.amazon.com/ses/home?region=eu-west-1#verified-senders-email:

• local folders, even if git ignored, can make the zappa package file larger, so clean up first:

  • pynt clean

• do a zappa deploy of the lambda function

  • zappa deploy dev

Updating deployment

• if you have already deployed once, do a zappa update of the lambda function
  • zappa update dev

Access to the Google Spreadsheet

Steps to setup the access:

• Obtain OAuth2 credentials from Google Developers Console
• create a Service Account Key you should end up with a json file containing the credentials including a private key, so keep this file private
• you must give your Google dev account access to the spreadsheet
  • browse to the spreadsheet and share it to the client_email listed in the json credentials file
• to run tests or run the Flask app locally, you'll need to export these credentials to an env var:
  • e.g. export DOJO_GAUTH_JSON="$(cat 'Dojo-monthly-emailer-0ea2b2dfe580.json')"
• when setting up a new travis-ci test runner, you'll also need to set this env var, and because it's injected unescaped into the shell, you must wrap the json value with single quotes
• the AWS lambda function also needs this value. Set in the Lambda Management Console, Code, Environment variables section

IFTTT (IF This Then That) applet setup

The steps to setup this trigger are very simple:

• sign up / login to IFTTT
• create a new applet
• for This, choose Date & Time every day at 9AM
• for That, choose Webhooks, with a GET request to the API Gateway URL
• I like to add a query param, like ?ifttt=1 to record the source of the request