Ansible: Orchestrate your Infrastructure

@magma_digital

Orchestrate your Infrastructure

Magma Digital Ltd

Jeremy Coates

@magma_digital

Who am I?๏ Jeremy Coates, MD at Magma Digital Ltd

๏ Founder of PHPNW

๏ Manchester Digital Association Council Member

๏ @phpcodemonkey

๏ linkedin.com/in/jeremycoates

@magma_digital

What isAnsible?

SALT CHEFPUPPET Ansible

@magma_digital

Whyuse it? Predictable

Consistent

Repeatable

Known state

Easy

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Install:Controller๏ Only install on controller machine

๏ Requires: Python 2.6+, Paramiko (ssh), PyYAML, Jinja2

๏ RedHat: yum install ansible

๏ Debian: apt-get install ansible

๏ OS X: brew install ansible

๏ All: pip install ansible or from source

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Install:Remotes๏ Nothing much!

๏ SSH server

๏ Python 2.4+ and simplejson module

๏ Or just Python 2.6+

๏ Essentially any *nix distro in last decade

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First 10 minutes๏ Command line usage:

• ansible -i hosts -m ping all

• ansible webserver -m setup

• ansible -i /path/to/hosts -m <module> [options e.g -vvvv] <host pattern>

• Default checks /etc/ansible/hosts

• -- check && -- diff

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Inventory: Hosts[webservers]web ansible_ssh_host=127.0.0.1 ansible_ssh_port=2222 ansible_ssh_user=vagrant ansible_ssh_private_key_file=~/.vagrant.d/insecure_private_key

web2 ansible_ssh_host=127.0.0.1 ansible_ssh_port=2201 ansible_ssh_user=vagrant ansible_ssh_private_key_file=~/.vagrant.d/insecure_private_key

[dbservers]db ansible_ssh_host=127.0.0.1 ansible_ssh_port=2202 ansible_ssh_user=vagrant ansible_ssh_private_key_file=~/.vagrant.d/insecure_private_key

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Inventory:Dynamic hosts๏ Plugin scripts for:

• Amazon EC2

• Digital Ocean

• Linode

• Vagrant

• + others

๏ Or create your own CMDB (Configuration Management DB)

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Playbooks๏ Commandline doesn’t scale: Playbooks do

๏ Playbooks are YAML

๏ ansible-playbook -i hosts playbook.yml

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Sample Playbook

--- - hosts: localhost user: root vars: motd_warning: 'WARNING: Use by ACME Employees ONLY' tasks: - name: setup a MOTD copy: dest=/etc/motd content={{ motd_warning }}

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Playbooks๏ Language of playbooks relatively familiar to devs

๏ Targets - groups of tasks / vars etc.

๏ Vars - nice and obvious!

๏ Tasks - actions using modules / vars

๏ Includes - re-usable components

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Playbooks Speed๏ Playbooks default to 5 forks

• -- forks <N> to vary this

๏ async: <seconds> for long running processes

๏ poll: <seconds> check the progress

๏ Tags: target sections of play books

๏ Roles: convention to enable reuse of playbooks

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Playbooks…๏ Looping: with_items:, with_fileglob:

๏ Conditional processing: when: ansible_os_family == ‘RedHat’

๏ Task Delegation: delegate_to: <host> or local_action: shorthand

๏ Vars: hostvars, groups, inventory*, environment

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Playbook Templates

๏ Jinja2 template engine. Has access to any ansible facts (vars)

๏ Comments: {# a comment #}

๏ If/else: {% if 'authorativenames' in group_names %} {% else %} {% endif %}

๏ Loops: {% for ip in ansible_all_ipv4_addresses %} {% end for %}

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Modules๏ Over 100 modules already exist

• Swiss army knife of machine management: ansible-doc

๏ Write own modules in any language, including PHP (json_encode)

๏ Module output key=value or JSON

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Ansible-pull๏ Runs on the machine to be configured

๏ Larger deployments (auto-scaling server farms etc.)

๏ Auto-update when repo changes

๏ Requires cron

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SHARE REUSEENHANCE

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Related?๏ ansible-vault - encryption for sensitive yaml files

๏ Ansible Guru - support subscription ($99/month)

๏ Ansible Tower (AWX) - commercial version

• Web console, REST API

• 50 machines from $2500/year (depending on support level needed)

๏ Vagrant - Ansible provisioner module

@magma_digital

ResourcesWebsite: ansible.com Documentation: docs.ansible.comTwitter: @ansibleIRC: #ansible (freenode)

Google Group: ansible-project Reddit: reddit.com/r/ansibleAnsible Weekly Newsletter: devopsu.comAnsible Configuration Management: (Daniel Hall: Packt Publishing Nov ’13 ISBN 978-1-78328-081-0)

@magma_digital

๏ Jeremy Coates, MD at Magma Digital Ltd

๏ Founder of PHPNW

๏ Manchester Digital Association Council Member

๏ @phpcodemonkey

๏ linkedin.com/in/jeremycoates

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