Trello-HipChat-Heroku

This is a (very) simple web application that picks up notifications from a Trello board, and posts an appropriate message to a HipChat room.

It currently supports the following 'actions' as defined by the Trello API:

• createCard - fired when a new card is created
• updateCard - fired whenever a card is changed in some way; the app currently only picks up card movements from one list to another - other updates are ignored
• commentCard - fired when someone adds a comment to a card
• updateCheckItemStateOnCard - fired when someone checks / unchecks a checklist item

The application has only one endpoint, set up to respond to the following url:

http://app/board_id/room_id

The app will unpack the board_id and combine that with the TRELLO_API_KEY and TRELLO_API_TOKEN settings to call the board API and retrieve all supported actions. Each comment is then sent to the HipChat room identified on the URL (using the HIPCHAT_API_TOKEN setting.)

If you wish to see what the Trello API returns, use the URL below along with a Trello API key (details on how to get your API key are below):

https://trello.com/1/boards/<trello_api_key>/actions?filter=createCard,commentCard,updateCard

The only additional complexity is that it uses the latest comment date returned as the 'since' API parameter value to prevent duplicate comments coming back. The value of the last date is stored in Redis, so that it is available to all processes. The key used is {{board}}_{{room}}.

I would recommend the following as background reading:

1. Heroku - https://devcenter.heroku.com/articles/quickstart
2. Flask documentation - http://flask.pocoo.org/docs/
3. Trello API - https://trello.com/docs/
4. HipChat API - https://www.hipchat.com/docs/api

Heroku setup

It is designed to run as a Flask app within Heroku, and as such there are some conventions that need to be adhered to. These are best described as the Zen of Heroku (in deference to the Zen of Python), a set of rules that Heroku requires you to follow when setting up your application to run on their infrastructure.

The only one that really matters from our point of view is that all settings (state) are held in environment variables, as opposed to config settings. The settings.py file therefore reads these settings out using os.environ.

In order to deploy this application to Heroku, you will need an account, and an application to which you can deploy. Refer to the docs above to read about how to deploy to Heroku using Git.

In order to get Redis running on Heroku, I can recommend installing the RedisToGo addon:

$ heroku addons:add redistogo:nano

In order to view the logs more easily you can add any one of a number of logging addons - both logentries and loggify work well:

$ heroku addons:add logentries:tryit

The following config variables will need to be set:

$ heroku config:add HIPCHAT_API_TOKEN=<your_token_here>
$ heroku config:add TRELLO_API_KEY=<your_token_here>
$ heroku config:add TRELLO_API_TOKEN=<your_token_here>

Adding RedisToGo will add the REDISTOGO_URL config setting.

How do I get a Trello API user token?

In order to get the relevant access keys and tokens for Trello, you should start by reading the docs: https://trello.com/docs/

However, if you want to shortcut that process, you need two things - your app's developer API key, which is the TRELLO_API_KEY settting, and a user access token, which is used to grant access to the relevant board / list / card.

1. Developer API key - log in to Trello and visit this page - https://trello.com/1/appKey/generate (it's the one marked 'Key')

2. User access token - Trello supports the ability to generate keys for read or read/write, and with varying expiration periods. The app only requires read-only access, for which you can use the following URL: https://trello.com/1/authorize?key=<TRELLO_API_KEY>&name=trello-hipchat&expiration=never&response_type=token&scope=read

The user (you, in this case) will be prompted to log in (if they are not already) - and once they've done that they will see a plain text page that includes the token.

TODO list

• Better management / administration (of tokens etc.)
• Custom formatting of messages
• Better examples / documentation