slides.md

title: Fabric name: inverse layout: true class: center, middle, inverse

#Fabric

Lord Junior 6th Gregory Eric Sanderson Turcot Temlett MacDonnell of Glengary Forbes of Linden

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What is fabric ?

• http://docs.fabfile.org
• SSH lib in python
• Automation of sysadmin tasks

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What about chef or puppet ?

• Similar goals
• Different approach
• Chef/Puppet are full-fledged frameworks
• Fabric feels more like a micro-framework
• I <3 python

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Hello world

fabfile.py

def hello():
    print("Hello world!")

running the code:

$ fab hello
Hello world!

Done.

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Multiple tasks

fabfile.py

def hello():
    print("Hello world!")

def world():
    print("World, Hello!")

running the code:

$ fab hello
Hello world!

Done.


$ fab world
World, hello!

Done.

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What system am I running ?

fabfile.py

from fabric.api import run

def system_type():
    run('unname -s')

running the code:

$ fab -H localhost system_type
[localhost] Executing task 'system_type'
[localhost] run: uname -s
[localhost] Login password for 'gregory': 
[localhost] out: Linux
[localhost] out: 


Done.
Disconnecting from localhost... done.

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Deployment example

fabfile.py

from fabric.api import *

DEFAULT_PATH = '/home/gregory/opencode'
DEPLOY_BRANCH = 'deploy'


def deploy(path=DEFAULT_PATH):
    add(path)
    commit(path)
    push(path)


def add(path=DEFAULT_PATH):
    with cd(path):
        local('git add -i')


def commit(path=DEFAULT_PATH):
    with cd(path):
        local('git commit -v')


def push(path=DEFAULT_PATH):
    with cd(path):
        local('git push origin master:%s' % DEPLOY_BRANCH)

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Deployment example

running the code:

[localhost] local: git add -i
[localhost] local: git commit -v
[master 001e95a] add hello world
 1 file changed, 5 insertions(+)
 create mode 100644 hello/fabfile.py
[localhost] local: git push origin master:deploy
Warning: Permanently added the RSA host key for IP address '192.30.252.130' to the list of known hosts.
Counting objects: 5, done.
Delta compression using up to 2 threads.
Compressing objects: 100% (3/3), done.
Writing objects: 100% (4/4), 394 bytes | 0 bytes/s, done.
Total 4 (delta 0), reused 0 (delta 0)
To git@github.com:gelendir/opencode-fabric.git
   3cc8181..001e95a  master -> deploy

Done.

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Error checking

fabfile.py

from fabric.api import run, settings, cd

DEPLOY_PATH = '/tmp/opencode-fabric'


def deploy():
    check_deployment()
    update()


def check_deployment():
    with settings(warn_only=True):
        command = run("test -d %s" % DEPLOY_PATH)
        if command.failed:
            run("git clone git://github.com/gelendir/opencode-fabric %s" % DEPLOY_PATH)


def update():
    with cd(DEPLOY_PATH):
        run("git pull")

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Error checking

running the code:

$ fab -H localhost deploy
[localhost] Executing task 'deploy'
[localhost] run: test -d /tmp/opencode-fabric
[localhost] Login password for 'gregory': 

Warning: run() received nonzero return code 1 while executing 'test -d /tmp/opencode-fabric'!

[localhost] run: git clone git://github.com/gelendir/opencode-fabric /tmp/opencode-fabric
[localhost] out: Cloning into '/tmp/opencode-fabric'...
[localhost] out: remote: Counting objects: 10, done.
[localhost] out: remote: Compressing objects: 100% (6/6), done.
[localhost] out: remote: Total 10 (delta 0), reused 10 (delta 0)
[localhost] out: Receiving objects: 100% (10/10), done.
[localhost] out: 

[localhost] run: git pull
[localhost] out: Already up-to-date.
[localhost] out: 


Done.
Disconnecting from localhost... done.

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Other nice features

• console.confirm
• with sudo()
• parallel execution
• roles
• hosts

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Real world examples

• LFS build scripts : https://github.com/gelendir/lfs-build
• XiVO prepare-rc-server : https://gitorious.org/xivo/xivo-tools/
• XiVO prepare-rc-client : https://gitorious.org/xivo/xivo-tools/

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Thank you !

• github : gelendir
• twitter : @gelendir
• email : gregory.eric.sanderson@gmail.com