Great programmers and sysadmins are lazy people: rightly, they prefer avoiding manual, time consuming and error-prone tasks such as installing and configuring a Linux, Apache, Tomcat cluster for the tenth time. With Ansible, an infrastructure (server, cloud) deployment automation & configuration both powerful AND simple (in most cases simpler than shell scripts and maven poms!), you can enjoy your coffee while it does all the work. The talk is very practical: I will set up a whole cluster in real time before the talk ends.

1. ●
Cloudy
Infrastructure as data with Ansible:
systems / cloud deployment and management for
the lazy developer
Carlo Bonamico - carlo.bonamico@nispro.it
NIS s.r.l. / JUG Genova
http://www.nispro.it / http://juggenova.net

2. What is this all about?
Carlo Bonamico JUG Genova / NIS s.r.l.
● Do you like
– Staying up late to reconfigure a server that went out of sync?
– Being unable to deploy a critical fix because the upgrade process
is so fragile and long that “it is better not to touch the system”?
– Having to rely on a server that took a week to setup, and lose it
because of an HD failure?
– Be unable to quickly scale your application on multiple servers
because the IT administration becomes too complex and
time-consuming?

3. Ansible Hello World
Carlo Bonamico JUG Genova / NIS s.r.l.
If the answer to these question is
NO!
Then this talk is for you!

4. What do we want?
Carlo Bonamico JUG Genova / NIS s.r.l.
● An easy way of quickly installing and
configuring new and existing servers
● A way of “syncing” the configuration to a
baseline when it drifts
● A way of recreating a machine as many times
as you need
– Reliably and with no effort
● A way of managing complex deployments
– And orchestrating interconnected services

5. What do we want?
Carlo Bonamico JUG Genova / NIS s.r.l.
● A way of doing all of those things
– EASILY
– QUICKLY
– RELIABLY
● Doing things automatically
– Ideally with no additional effort vs doing things
manually (and with less mistakes!)

6. An Agile Approach
Carlo Bonamico JUG Genova / NIS s.r.l.
Our highest priority is to satisfy the customer
through early and continuous delivery of valuable software.
Simplicity
--the art of maximizing the amount of work not done--
is essential.
The Agile Manifesto

7. Enter Ansible
Carlo Bonamico JUG Genova / NIS s.r.l.
● Ansible is your friend!
– A tool for doing things automatically
●With LESS effort than doing them manually
● It provides
– Remote command execution across multiple machines
– File, package and configuration distribution
– Automated installations and deployments

8. What's inside?
Carlo Bonamico JUG Genova / NIS s.r.l.

9. Enter Ansible
Carlo Bonamico JUG Genova / NIS s.r.l.
● Created by Michael De Haan of Cobbler
fame
– Open Source @
https://github.com/ansible/ansible/
– now supported by AnsibleWorks
● Well documented
● Growing, active and supportive
community
–

10. Enter Ansible
Carlo Bonamico JUG Genova / NIS s.r.l.
● Minimal install
sudo add-apt-repository ppa:rquillo/ansible
●
● sudo apt-get update
● sudo apt-get install ansible -y
● Minimal requirements
– Python 2.6 on the commander
– Python 2.4 on the nodes
– Three phyton packages (autoinstall)

11. How does Ansible work?
Carlo Bonamico JUG Genova / NIS s.r.l.
● Work on all Unix/Linuxes
– And Windows with cygwin (currently
limited)
● Transport over SSH
– (and other protocols in the future)
● Inventory, configuration and playbooks in
YAML
● No DB is involved

12. Getting Started
Carlo Bonamico JUG Genova / NIS s.r.l.
● SSH Key Pair
– ssh-keygen -b 2048
enter pizzamatic_rsa as filename
●
● Configure /etc/hosts or DNS
● Configure ansible_hosts
– .ini format
– Hosts
– Groups, with []

13. Pizzamatic Time!
Carlo Bonamico JUG Genova / NIS s.r.l.

14. Pizzamatic infrastructure
Carlo Bonamico JUG Genova / NIS s.r.l.
● Front-end server with Apache2 and mod_proxy
● Back-end application servers with Tomcat 7
● Postgresql DB
● Common features
– Ssh public key – passwordless login
– Ufw for firewall

15. First steps
Carlo Bonamico JUG Genova / NIS s.r.l.
● ansible -k -m ping -u pizzamatic
pizzamatic-fe-test-01
– -k means ask password
– -m means module (ping)
– -u connection user
– Target host

16. First steps
Carlo Bonamico JUG Genova / NIS s.r.l.
● ssh-agent
● ssh-add ~/.ssh/pizzamatic_rsa
● ansible -k -m ping -u pizzamatic
pizzamatic-fe-test-01
● If it hangs, either
– You forgot the -k, and a certificate was not
installed (or viceversa)
– You added the -K (sudo password), and
passwordless sudo is enabled

17. Move to Playbooks
Carlo Bonamico JUG Genova / NIS s.r.l.
● Efficient way of describing the desired
configuration of multiple hosts
– And then “apply” it
– Incrementally
Auto-resume
●
● Synchronization
● Versioning
● ansible-playbook pizzamatic.playbook

18. BDD with Infrastructure???
Carlo Bonamico JUG Genova / NIS s.r.l.
● First, descrive desired infrastructure
status as plain text
– #pizzamatic service requires
front-end
– #pizzamatic service requires
application servers
● Then translate it incrementally in
ansible “actions” → execute it!

19. Actions: an example
Carlo Bonamico JUG Genova / NIS s.r.l.
#Installing and configuring Apache 2
­ name: Ensure Apache2 is installed
action: apt pkg=apache2
­ name: Generate the virtual host configuration
action: template src=src/${service.name}­ssl.j2
dest=/etc/apache2/sites­available
­ name: Ensure the site is up
action: command a2ensite ${service.name}­ssl
­ action: service name=apache2 state=started

20. Ansible Actions
Carlo Bonamico JUG Genova / NIS s.r.l.
● Not ideal term! Very often “actions”
do nothing!
– Because the system is already in
the desired state
●action: file dest=/home
state=present
● They do something only if the system
is not in the desired state

21. Ansible Actions
Carlo Bonamico JUG Genova / NIS s.r.l.
● Most Ansible Actions are Idempotent
– “big word” meaning that you can
repeat them as many times as you
want and always get the same
result
● In practice, it's what makes ansible
useful

22. BDD with Infrastructure???
Carlo Bonamico JUG Genova / NIS s.r.l.
● Red
– Error
● Yellow
– Applied, changed
● Green
– Already in the desired state

23. Infrastructure as what?
Carlo Bonamico JUG Genova / NIS s.r.l.
Ansible = Infrastructure as Data
You describe your infrastructure
You version the description
“Applying” the description and actually
ensuring that the infrastructure exists and is
in the desired state is an implementation
detail (and up to ansible, not you)

24. Ansible Modules
Carlo Bonamico JUG Genova / NIS s.r.l.
● Clean and modular way of defining
actions
– Encapsulate best practices
– A single ansible action encapsulates
lines and lines of shell scripts
● Very strong emphasis on reuse

25. Ansible Modules
Carlo Bonamico JUG Genova / NIS s.r.l.
● Implemented in any language
– Python, java, bash...
– Core modules are in python
● Input: parameter string
● Output: json data

26. Ansible Modules
Carlo Bonamico JUG Genova / NIS s.r.l.
● add_host ● mount
● apt ● mysql_db
● apt_key ● mysql_user
● apt_repository ● pause
● authorized_key ● ping
● command ● postgresql_db
● copy ● postgresql_user
● cron ● s3
● ec2 ● script
● fetch ● service
● file ● shell
● get_url ● subversion
● git ● template And many more!
● group ● user
● hg ● virt
● lineinfile ● wait_for
● mail ● yum

27. Variables
Carlo Bonamico JUG Genova / NIS s.r.l.
● Declared
– In the ansible_hosts file
– individual YAML files relative to the
inventory file
● e.g. host_vars/pizzamatic-fe-test-01
---
ntp_server: acme.example.org

28. Facts
Carlo Bonamico JUG Genova / NIS s.r.l.
● Automatically collected facts about
systems involved in the playbook
– ${inventory_hostname}
– ${ansible_eth0.ipv4.address}
● Can be use as variables in playbook
and templates

29. Templates
Carlo Bonamico JUG Genova / NIS s.r.l.
● Jinja2 templates
– very similar to java ${property}
syntax
● Env.sh.j2
– export JAVA_HOME=/home/$
{service.user}/jdk1.7.0
– export PATH=$PATH:$JAVA_HOME/bin

30. Handlers
Carlo Bonamico JUG Genova / NIS s.r.l.
● Respond to asynchronous events
handlers:
­ name: restart ssh
action: service name=ssh
state=restarted

31. Playbooks
Carlo Bonamico JUG Genova / NIS s.r.l.
●
Structure
---
­ hosts: pizzamatic­fe­test­01
gather_facts: yes
user: pizzamatic
sudo: yes
vars_files:
­ pizzamatic.yml
vars:
name: pizzamatic
tasks:
­ include: pizzamatic­fe.playbook #child sees parent variables and params

32. File management and transfer
Carlo Bonamico JUG Genova / NIS s.r.l.
● To the nodes
– ansible atlanta ­m copy ­a "src=/etc/hosts
dest=/tmp/hosts"
– ansible webservers ­m file ­a "dest=/srv/foo/b.txt
mode=600 owner=mdehaan group=mdehaan"
– ansible webservers ­m file ­a "dest=/path/to/c
mode=644 owner=mdehaan group=mdehaan state=directory"
– ansible webservers ­m file ­a "dest=/path/to/c
state=absent"
● From the nodes
– Use the fetch module

33. Best Practices
Carlo Bonamico JUG Genova / NIS s.r.l.
● Good old Software Engineering Principles
still apply!
– Dont Repeat Yourself
– Good Names make the difference
– Be simple
– S.O.L.I.D.
● http://butunclebob.com/ArticleS.Uncl
eBob.PrinciplesOfOod

34. Useful Tools
Carlo Bonamico JUG Genova / NIS s.r.l.
● Yaml Editor for Eclipse
– https://code.google.com/p/yedit/
– https://code.google.com/p/yamledito
r/
● Git & Mercurial

35. References
Carlo Bonamico JUG Genova / NIS s.r.l.
And
● Ansible Home & Ansible Docs the very active
– http://www.ansible.cc google group
ansible-project
● Extras
– http://www.ansible.cc/docs/contrib.html
● Presentations
– https://speakerdeck.com/mpdehaan/ansible
● AnsibleWorks
– http://www.ansibleworks.com/
● This tutorial
– https://github.com/carlobonamico/ansible-tutorial

36. References
Carlo Bonamico JUG Genova / NIS s.r.l.
● My blog
– http://www.carlobonamico.com Thank you
● My Company
for your attention!
– http://www.nispro.it
● JUG Genova
– http://juggenova.net
● Attend a course
– Infrastructure Management with Ansible (2 days)
– http://www.nispro.it/education