This document discusses deploying Python applications to Heroku using Flask, CoffeeScript, Fabric, and other tools. It outlines the requirements, getting started steps including installing dependencies and using Procfiles and Foreman to run locally. It then covers deploying the application to Heroku using Git, and some tips for Heroku logging. Finally, it provides an example of a sample Flask application that serves Memphis concert ticket data using HTML templating, CoffeeScript, and the SeatGeek API.

1. Quick and Dirty Python
Deployments with Heroku
Guest starring Flask, CoffeeScript, Fabric, and
SeatGeek
Daniel Pritchett for MEMpy,
March 19, 2012

2. Painless Heroku Startup

3. Requirements
• Python 2.7
• virtualenv
• pip
• Rubygems
• Procfile / foreman

4. Get started
• Install git, foreman, pip, virtualenv
• Clone/create a repo with a Procfile that
starts a HTTP service
• foreman start to test it locally
• heroku create app_name –
stack=cedar && git push heroku
master

5. Setup log
$ virtualenv --no-site-packages heroku_demo
New python executable in heroku_demo/bin/python
Installing pip...............cdone.
$ cd heroku_demo/
$ . bin/activate
$ git clone git://github.com/dpritchett/wwebsite-python.git app
$ cd app
$ pip install -r ./requirements.txt
Successfully installed Flask Jinja2 Pygments Werkzeug chardet gunicorn
$ foreman start
13:20:18 web.1 | started with pid 17810
13:20:18 web.1 | 2012-03-19 13:20:18 [17810] [INFO] Starting gunicorn 0.14.1
13:20:18 web.1 | 2012-03-19 13:20:18 [17810] [INFO] Listening at: http://0.0.0.0:5000
$ heroku create mempy-demo --stack=cedar
Creating mempy-demo... done, stack is cedar
http://mempy-demo.herokuapp.com/ | git@heroku.com:mempy-demo.git
Git remote heroku added
$ git push heroku master
Procfile declares types -> web
http://mempy-demo.herokuapp.com deployed to Heroku
$ curl mempy-demo.herokuapp.com
Hello World!

6. Foreman’s Procfile defines the service
web: gunicorn app:APP -b 0.0.0.0:$PORT -w 3
You can run the same thing at the console to test:
$ gunicorn app:APP -b 0.0.0.0:$PORT -w 3

7. Heroku logging
• Captures stdout, stderr
• You’ll need it since you have no persistent disk
• Simplest case you can just use a print statement
• Free plan has limitations
• Consider an offsite log manager

8. Remote console
$ heroku run bash
Running bash attached to terminal... up, run.2
~ $ find templates
templates
templates/index.html
~ $ find static
static
static/js
static/js/memphis_tickets.js
static/coffee
static/coffee/memphis_tickets.coffee
static/bootstrap
static/bootstrap/js
static/bootstrap/js/bootstrap.js
...
static/bootstrap/css/bootstrap.css
static/css
static/css/tickets.css
~ $

9. Sample Flask application:
TicketsOfMemphis.com

11. The entire backend

12. HTML templating (Jinja2)

13. CoffeeScript excerpts

14. Data provided by SeatGeek API

15. Honorable mention: Fabric
$ fab s
[localhost] local: coffee -o ../js/ --compile
./*coffee
[localhost] local: foreman start
14:11:29 web.1 | started with pid 24218
14:11:29 web.1 | 2012-03-19 14:11:29
[24218] [INFO] Starting gunicorn 0.14.1
14:11:29 web.1 | 2012-03-19 14:11:29
[24218] [INFO] Listening at: http://0.0.0.0:5000
(24218)
14:11:29 web.1 | 2012-03-19 14:11:29
[24218] [INFO] Using worker: sync
14:11:29 web.1 | 2012-03-19
14:11:29 [24225] [INFO] Booting worker with pid:
24225
14:11:29 web.1 | 2012-03-19 14:11:29
[24226] [INFO] Booting worker with pid: 24226
14:11:29 web.1 | 2012-03-19 14:11:29
[24227] [INFO] Booting worker with pid: 24227

16. Heroku Ecosystem
Pain points and add-ons

17. addons.heroku.com
• Databases
• Worker hours
• Email services
• DNS
• HTTPS and certificates
• Billing
• Message/Task Queues

18. LogEntries

19. LogEntries Alerts

20. Zerigo DNS

21. MongoHQ

22. Thank you!
Try a copy of the code at
github.com/dpritchett/wwebsite-python
Heroku and Flask have great docs.
Find me @dpritchett