Introduction to Automated Deployments with Ansible

1 COMPANY CONFIDENTIAL – DO NOT DISTRIBUTE #Dynatrace
System Architects with DevOps / Security Group Meetup, Vienna
18th December 2014
Martin Etmajer, @metmajer, Technology Strategist @ Dynatrace
Introduction to
Automated Deployments with Ansible

• Automated Deployments in Continuous Delivery
• Agent-based vs. Agentless Solution Architectures
• Introduction to Ansible
Agenda

Automated Deployments
in Continuous Delivery

feature cycle time time
Customer Users
Utmost Goal: Minimize Cycle Time

Customer Users
minimize

Customer
This is when you
create value!
minimize

Customer
You
This is when you
create value!
minimize

The definition of a deployment pipeline,
which is at the heart of Continuous Delivery:
“A deployment pipeline is, in essence, an automated implementation
of your application’s build, deploy, test and release process.”
Jez Humble & Dave Farley in Continuous Delivery
“Use machines for what they’re good at, use people for what they’re good at.”
Dave Farley at PIPELINE Conference 2014 @vimeo.com/96173993
The Role of Automation in Continuous Delivery

Manual deployments:
• are slow and prone to human errors
• are neither repeatable nor reliable
• are not consistent across environments
• are done by a few experts: hinders collaboration
• require extensive documentation: often outdated
The Problem with Manual Deployments
We are just not good at it!

Agent-based vs. Agentless
Solution Architectures

Agent-Based Solutions

Agent-Based Deployments (Chef, Puppet)

» Can be used in client-server or client-only modes
» Client must be installed on each host to be provisioned
» Clients have dependencies
» Not laid out for server orchestration by design
(do something on server A, then on server B, etc.)
» Chef and Puppet are widely considered to have a large entrance
barrier and are complex to use

Agentless Solutions

Agentless Deployments (Ansible)

Ansible

» Written and extensible in Python
» Human- and machine-readable configuration (YAML)
» No boot-strapping required on deployment hosts (SSH)
» Statements are executed in the order they were specified
» Simple, easy to ramp up with (think of new employees!)
» Clear and concise documentation
Ansible

Ansible Concepts:
Ad-hoc Commands

Ansible Concepts: Ad-hoc Commands
ansible [-i inventory] <host-pattern> [options]
Examples?
» ansible localhost -m copy –a ‘src=/usr/bin/a dest=/usr/bin/b’
» ansible webserver –a ‘/sbin/reboot’ –f 3
–u deploy ––sudo ––ask–sudo–pass
Module Arguments

Ansible Concepts: Ad-hoc Commands
ansible [-i inventory] <host-pattern> [options]
Examples?
» ansible localhost -m copy –a ‘src=/usr/bin/a dest=/usr/bin/b’
» ansible webserver –a ‘/sbin/reboot’ –f 3
–u deploy ––sudo ––ask–sudo–pass
Processes
User Use sudo
Ask password
interactively

Ansible Concepts:
Inventories

Ansible Concepts: Inventories
» Ansible provisions groups of servers at once
» Groups and hosts are stored in inventory files
» An inventory file is expressed in the INI format

Ansible Concepts: Inventories
# production.ini
[web]
web[0-1].example.com
[frontends]
frontend.example.com
[backends]
backend.example.com
Group
Host

Ansible Concepts:
Playbooks

Ansible Concepts: Playbooks
ansible-playbook [–i <inventory>] <playbook>
Playbooks
» describe policies your remote systems shall enforce
» consist of variables, tasks, handlers, files and roles
» are expressed in the YAML format

--- # webservers.yml
- hosts: web
vars_files:
- variables.yml
handlers:
- name: reload apache2
service: name=apache2 state=reloaded
tasks:
- name: Install Apache HTTP Server
apt: name=apache2 update_cache=yes
- name: Install Apache Modules
apache2_module: name={{ item }} state=present
with_items:
- proxy
- proxy_httpd
notify: reload apache2
Play
Module

...
- name: Install Apache Configuration
template: >
src=apache-config.conf.j2
dest={{ apache_conf_home }}/myapp
mode=0644
notify: reload apache2
remote_user: deploy
sudo: yes

--- # variables.yml
apache_conf_home: /etc/apache2/conf.d

--- # playbook.yml
- include: appservers.yml
- include: dbservers.yml
- include: webservers.yml
Includes multiple plays
into a single playbook

ansible-playbook –i production.ini webservers.yml
PLAY [web]
******************************************************
TASK: [Install Apache HTTP Server]
************************
changed: [web0.example.com]
changed: [web1.example.com]
...
PLAY RECAP
************************************************************************
web0.example.com : ok=3 changed=3 unreachable=0 failed=0
web1.example.com : ok=3 changed=3 unreachable=0 failed=0
Run!

Ansible Modules Library

Ansible Modules Library
» Cloud: AWS, Azure, DigitalOcean, Docker, Google, OpenStack,...
» Database: MySQL, Postgresql,...
» Packaging: apt, yum, easy_install, npm, homebrew, zypper,...
» Source Control: git, subversion, mercurial,...
» Web Infrastructure: apache2_module, jira,...
» System: mount, selinux, ufw, user,...

Ansible Concepts: Roles (Outlook)

Ansible Concepts: Playbooks » Roles
Roles
» Are the preferred means to organize and reuse related tasks
» Build on the idea of include files to form clean abstractions
» Can be shared and found on Ansible Galaxy

Ansible Concepts: Playbooks » Roles
Reusing Roles in a Play
--- # webservers.yml
- hosts: web
roles:
- { role: common }
- { role: apache2 }
remote_user: deploy
sudo: yes

Introduction to Automated Deployments with Ansible

Recommended

Recommended

More Related Content

What's hot

What's hot (20)

Viewers also liked

Viewers also liked (20)

Similar to Introduction to Automated Deployments with Ansible

Similar to Introduction to Automated Deployments with Ansible (20)

Recently uploaded

Recently uploaded (20)

Introduction to Automated Deployments with Ansible

Editor's Notes