1. Provisioning, Config, Execution, (more) Fun

2. Steve Pereira
18 years in IT
Startups and Enterprise
Love learning about,
teaching and talking about:
• DevOps
• CI/CD
• Automation
• Scale
WHO AM I?

3. ANSIBLE FEATURES
• Automation for local and remote system provisioning
• Automation for local and remote applications deployment
• No agents to install on remote systems
• Using existing SSHd on remote systems and native SSH on host
• Parallel by default - scale to 6000 targets with single master
• Language that approaches plain english

4. ANSIBLE CONVENTIONS
Playbooks - contain required tasks to configure systems and deploy
Tasks - individual actions to perform on remote or local machines
Roles - modular, single-purpose configurations for systems
Inventory - files containing address information of target machines
Handlers - actions triggered by tasks
Templates - customizable files destined for managed machines

5. MINIMUM VIABLE ANSIBLE
$ ansible all -i 'localhost,' -c local -m ping
localhost | success >> {
"changed": false,
"ping": "pong"
}

6. WHAT ELSE?
• ansible webservers -m setup
• ansible lb -m copy -a "src=hosts dest=/tmp/hosts”
• ansible webservers -m yum -a "name=curl state=installed”
• ansible webservers -m service -a "name=nginx
state=restarted”
• ansible-doc -l

7. PLAYBOOKS---
- hosts: webservers
vars:
http_port: 80
max_clients: 200
remote_user: root
tasks:
- name: ensure apache is at the latest version
yum: pkg=httpd state=latest
- name: write the apache config file
template: src=/srv/httpd.j2 dest=/etc/httpd.conf
notify:
- restart apache
- name: ensure apache is running (and enable it at boot)
service: name=httpd state=started enabled=yes
handlers:
- name: restart apache
service: name=httpd state=restarted
example_playbook.yml

8. PLAYBOOKS---
- hosts: webservers
vars:
http_port: 80
max_clients: 200
remote_user: root
tasks:
- name: ensure apache is at the latest version
yum: pkg=httpd state=latest
- name: write the apache config file
template: src=/srv/httpd.j2 dest=/etc/httpd.conf
notify:
- restart apache
- name: ensure apache is running (and enable it at boot)
service: name=httpd state=started enabled=yes
handlers:
- name: restart apache
service: name=httpd state=restarted
example_playbook.yml

9. PLAYBOOKS---
- hosts: webservers
vars:
http_port: 80
max_clients: 200
remote_user: root
tasks:
- name: ensure apache is at the latest version
yum: pkg=httpd state=latest
- name: write the apache config file
template: src=/srv/httpd.j2 dest=/etc/httpd.conf
notify:
- restart apache
- name: ensure apache is running (and enable it at boot)
service: name=httpd state=started enabled=yes
handlers:
- name: restart apache
service: name=httpd state=restarted
example_playbook.yml

10. PLAYBOOKS---
- hosts: webservers
vars:
http_port: 80
max_clients: 200
remote_user: root
tasks:
- name: ensure apache is at the latest version
yum: pkg=httpd state=latest
- name: write the apache config file
template: src=/srv/httpd.j2 dest=/etc/httpd.conf
notify:
- restart apache
- name: ensure apache is running (and enable it at boot)
service: name=httpd state=started enabled=yes
handlers:
- name: restart apache
service: name=httpd state=restarted
example_playbook.yml

11. PLAYBOOKS---
- hosts: webservers
vars:
http_port: 80
max_clients: 200
remote_user: root
tasks:
- name: ensure apache is at the latest version
yum: pkg=httpd state=latest
- name: write the apache config file
template: src=/srv/httpd.j2 dest=/etc/httpd.conf
notify:
- restart apache
- name: ensure apache is running (and enable it at boot)
service: name=httpd state=started enabled=yes
handlers:
- name: restart apache
service: name=httpd state=restarted
example_playbook.yml

12. PLAYBOOKS---
- hosts: webservers
vars:
http_port: 80
max_clients: 200
remote_user: root
tasks:
- name: ensure apache is at the latest version
yum: pkg=httpd state=latest
- name: write the apache config file
template: src=/srv/httpd.j2 dest=/etc/httpd.conf
notify:
- restart apache
- name: ensure apache is running (and enable it at boot)
service: name=httpd state=started enabled=yes
handlers:
- name: restart apache
service: name=httpd state=restarted
example_playbook.yml

13. PLAYBOOKS---
- hosts: webservers
vars:
http_port: 80
max_clients: 200
remote_user: root
tasks:
- name: ensure apache is at the latest version
yum: pkg=httpd state=latest
- name: write the apache config file
template: src=/srv/httpd.j2 dest=/etc/httpd.conf
notify:
- restart apache
- name: ensure apache is running (and enable it at boot)
service: name=httpd state=started enabled=yes
handlers:
- name: restart apache
service: name=httpd state=restarted
example_playbook.yml

14. ROLES
my_role/
README.md (readme)
defaults/ (default values)
meta/ (role metadata)
files/ (binaries)
templates/ (file templates)
handlers/ (operation handlers)
tasks/ (playbook files)
vars/ (custom variables)
• Easily packaged and shared
• Download community roles
• Mix and match

15. INVENTORY
• Define how ansible will interact with remote hosts
• Define logical groups of managed nodes
• One file for each environment
• Default location : /etc/ansible/hosts
• INI format, variable overrides
sample_inventory.ini [loadbalancers]
10.20.30.41
10.20.30.42
[webservers]
10.20.30.51 hostname=artemis
10.20.30.52 hostname=apollo

16. TEMPLATES
• Use Jinja2 templating and variables to customize
• Defaults available when variables not provided (dev default with prod override)
etc_logrotate.d.j2 {{ logfile }} {
rotate {{ 7 | rotate_max }}
{{ daily | frequency }}
compress
missingok
notifempty
}

17. IT CAN GET FANCY
tasks:
- name: install packages in a users virtualenv
shell: su - c {{ item[0] }} '(. ./bin/activate && pip install {{ item[1] }})'
with_nested:
- [ 'jim', 'joe', 'jack' ]
- [ package1==1.1,
package2==1.2,
package3==1.3 ]
There are several types of loops:
Hashes, Fileglobs, Sequence, Subelements, First match, Command results, Random and
more
but there’s a builtin pip module, anyways.

18. CONDITIONALS
tasks:
- command: /bin/false
register: result
ignore_errors:True
- command: /bin/something
when: result|failed
- command: /bin/something_else
when: result|success
- command: /bin/still/something_else
when: result|skipped
The result of a play can depend on
the value of a variable, fact
(something learned about the
remote system), or previous task
result.

19. MORE CONDITIONALS!
tasks:
- shell: echo "I've got '{{ foo }}'"
when: foo is defined
- fail: msg="This play requires 'bar'"
when: bar is not defined
- command: echo {{ item }}
with_items: [ 0, 2, 4, 6, 8, 10 ]
when: item > 5
If a required variable has not been
set, you can skip or fail using
Jinja2’s defined test. For example:

20. SIMPLE, POWERFUL BUILTINS
• 261 built-in modules
• Many cloud providers, packages and tools are integrated
• Easily add your own in any language
examples: • ec2 - Create, terminate, start/stop an instance
• docker - Manage docker containers
• hipchat Send a message to hipchat
• s3 - manage objects in S3
• twilio - Sends a text message to a phone
• win_service - Manages Windows services
• zfs - Manage zfs

21. SMOOTH OPERATION
•Get and set variables easily
•Simple variable precedence
•Ordered, predictable execution
•Tagged, resumable execution
•ansible doc [foo]

22. SECURITY
• Can be centralized and locked down via Ansible Tower
• Can be run from a centralized bastion server
• Vault encrypts sensitive data
• Uses ordinary SSH, paramiko or custom transport plugins
• No extra open ports, use your own user account, sudo!
• No agents to update or risk vulnerabilities

23. ADVANCED CAPABILITIES
• Rolling updates/deployment/orchestration (1, 5, n at a time)
• Canary testing (check for page content or response code)
• Variable timeouts and parellelism
• Ansible-pull to invert execution - nodes check in to a master

24. MORE INFORMATION
https://docs.ansible.com
https://docs.ansible.com/playbooks_best_practices.html
https://galaxy.ansible.com
https://github.com/ansible/ansible-examples

25. QUESTIONS?
@steveElsewhere
http://linkedin.com/in/devopsto

26. THANK YOU!
http://devopsdays.org/events/2015-toronto
(shameless plug)