The slides from my July Django-District presentation. It shows some of the basics of using the new fabric. I have uploaded the example fabfile.py to slideshare as well.

1. Pythonic Deployment with Fabric 0.9
Corey Oordt
The Washington Times
@coordt
coordt@washingtontimes.com
http://opensource.washingtontimes.com/

2. Easy Deployment for Different Environments
Testing
Staging
Production

3. Easy Deployment to Multiple Computers
Production 1
Production 2
Production 3

4. Installation of Fabric
$ easy_install paramiko
$ easy_install pycrypto
$ easy_install http://git.fabfile.org/cgit.cgi/fabric/
snapshot/fabric-0.9b1.tar.gz

5. Fabric is just a command and a python script
fab fabfile.py

6. The fabfile.py
from fabric.api import *
env.roledefs = {
'web': ['172.16.12.1', '172.16.12.2',],
'media': ['172.16.12.4',],
'staging': ['172.16.12.5',],
'testing': ['172.16.12.6',],
'database': ['172.16.12.7', '172.16.12.8',],
}
env.root_path = '/var/websites'

7. Define Tasks to Setup Environments
def testing():
env.hosts = env.roledefs['testing']
env.user = 'testuser'
def staging():
env.hosts = env.roledefs['staging']
env.user = 'staginguser'
def production():
env.hosts = env.roledefs['web']
env.user = 'produser'

8. Task Example
def clean(site=None):
"""Remove .pyc files from a site."""
from os import path
if not site:
site = prompt('Please specify which site(s) to
clean (a comma delimited list is accepted): ',
validate=r'^[w-.,]+$')
site_list = site.split(',')
for item in site_list:
path = path.join(env.root_path, item)
sudo("find %s -name '*.pyc' -depth -exec rm {} ;"
% path)

9. Fabric Commands
• require: Make sure that certain environment variables are available.
• prompt: Display a prompt to the user and store the input in the given
variable. Validation is optional.
• put: Upload files to the remote host(s).
• get: Download a file from a remote host.
• run: Run a shell command on the remote host(s).
• sudo: Run a root privileged shell command command on the remote host(s).
• local: Run a command locally.

10. Fabric Contrib Commands
• rsync_project: Synchronize a remote directory with the current project
directory via rsync.
• upload_project: Upload the current project to a remote system, tar-gzipping
during the move.
• exists: Return True if given path exists.
• first: Given one or more file paths, returns first one found, or None.
• upload_template: Render and upload a template text file to a remote host.
• sed: Run a search-and-replace on filename with given regex patterns.
• comment/uncomment: Attempt to (un)comment out all lines in filename
matching regex.
• contains: Return True if filename contains text.
• append: Append string (or list of strings) text to filename.
• confirm: Ask user a yes/no question and return their response as True /False.

11. Fabric Decorators
• hosts: Defines on which host or hosts to execute the wrapped function.
• roles: Defines a list of role names, used to look up host lists.
• runs_once: Prevents wrapped function from running more than once.
@hosts('user1@host1', 'host2', 'user2@host3')
@runs_once
def my_func():
pass
@roles('web')
def my_other_func():
pass

12. Usage Example
$ fab testing clean:site=basenews
[172.16.12.6] sudo: find /var/websites/basenews -name
'*.pyc' -depth -exec rm {} ;
Password for testuser@192.168.56.3:
Done.
Disconnecting from 172.16.12.6... done.
$

13. Example Uses
• Reload web server settings
• Clean .pyc files
• Check out new revision from a SCM repository
• Install packages on servers
• Apply patches
• Restart caching server
• Dump database and restore it locally

14. Let’s look at an example fabfile.py…

15. Thank You
Corey Oordt
The Washington Times
@coordt
coordt@washingtontimes.com
http://opensource.washingtontimes.com/