Testing for infrastructure as code for AnsibleFest 2016

© Mike Caspar, 2016
Testing for Infrastructure as Code by Mike Caspar
is licenced under an Attribution-ShareAlike 4.0 International licence
Testing for Infrastructure as Code
A Beginner's Pattern
Presented by: Mike Caspar
Incremental Infrastructure
Coach

The Audience?

Caspar Computer Services Inc.
-- Innovative Solutions since 1984 -
-
Caspar.NET
(5 cities in Canada / 10
years)

Why am I here?

How do we start?
Very basic understanding of Ansible Inventory &
Groups
A sample environment
A starting pattern (The Test/Maintain Loop)
Moving machines between environments
Integrating Testing into the process (TDD for
Infrastructure)
Q & A

Physical Servers Virtual Servers
Ansible works with both.

Applications…
Not servers.

Physical and Virtual Infrastructure
Production
Development
Staging (sort of)

Inventory - Folders by Application Name
WALDO and GROVER are Application names…
Why is this important ?

Inventory - Host Location and Types
City
Env.

Application - Group Variables
---
# Playbook: GROVER_maintain_proxy.yml
# This playbook Maintains the GROVER Application
- name: ensure hosts are setup correctly on proxy servers in yyz
hosts: GROVER_yyz_proxy_staging, GROVER_yyz_proxy_dev, GROVER_yyz_proxy_prod
remote_user: root

Tests can be attached and versioned along
with a specific version of Infrastructure
(think... testing & rollbacks)
Source Control….
Why ?

Host Names not IP Addresses !
(virtual machines)

group_vars matching basics
Playbook hosts + Inventory + group_vars + --limit

group_vars matching basics
Playbook hosts + Inventory + group_vars + --limit
remote_user: root
Playbook
Inventory
group_vars
[GROVER_yyz_proxy_prod]
yyzproxy1.caspar.com
[GROVER_yyz_webservers_prod]
web1.caspar.com

The Test/Maintain Loop
_test
(govern)
_maintain
(dev)
_setup
(injected once)

The continual loop
( Dev/Test Continuous Loop)
APP_Maintain_serverType.yml
APP_Test_serverType.yml
APP_Maintain_serverType.yml
APP_Test_serverType.yml

Adding a new Application (in dev/staging first)
APP_maintain_serverType.yml
APP_test_serverType.yml
APP_setup_serverType.yml (injected into loop only once).
APP_test_serverType.yml
( _setup injected only once )
_test
(govern)
_maintain
(dev)

---
# Playbook: GROVER_maintain_proxy.yml
# This playbook Maintains the GROVER Application
remote_user: root
roles:
- { role: GROVER-common }
- { role: GROVER-users }
- { role: GROBER-firewalls } tags: ['security'] }
- { role: COMMON-newrelic, state: present, tags: ['monitoring'] }
- { role: COMMON_puppet_agent, state: absent }
- name: ensure hosts are setup correctly on proxy servers in yul
hosts: GROVER_yul_proxy_staging, GROVER_yul_proxy_dev, GROVER_yul_proxy_prod
remote_user: root
roles:
- { role: GROVER-common }
- { role: GROVER-users }
- { role: GROBER-firewalls } tags: ['security'] }
- { role: COMMON-newrelic, state: present, tags: ['monitoring'] }
- { role: COMMON_puppet_agent, state: absent }
Notice the Application Name

We decide when a machine is in Dev/Staging/Production
(not physical location)
Production
Development
Staging (sort of)
To move a machine from Staging to Production….
Move it to another Inventory and run APP_maintain_

ansible-playbook -i Inventory/GROVER/yyz/dev/GROVER_test_proxy.yml
ansible-playbook -i Inventory/GROVER/yyz/staging/GROVER_test_proxy.yml
ansible-playbook -i Inventory/GROVER/yyz/prod/GROVER_test_proxy.yml
ansible-playbook -i Inventory/GROVER/yyz/dev/GROVER_test_proxy.yml --limit a.host.com
ansible-playbook -i Inventory/GROVER/yyz/staging/GROVER_test_proxy.yml --limit a.host.com
ansible-playbook -i Inventory/GROVER/yyz/prod/GROVER_test_proxy.yml --limit a.host.com
ansible-playbook -i Inventory/GROVER/yyz/dev/GROVER_maintain_proxy.yml
ansible-playbook -i Inventory/GROVER/yyz/staging/GROVER_maintain_proxy.yml
ansible-playbook -i Inventory/GROVER/yyz/prod/GROVER_maintain_proxy.yml
Example commands
White - Dev
Blue - QA/Test
Orange - Governance/Ops

Be careful of role
defaults
Empty Strings
Length of group_vars tag

Why test_ instead of --check?

TDD - Test Driven Development
(learned from the Software Community)
THINK !
Write a Failing Test
Refactor
Make it Pass
http://www.extremeprogramming.org/rules/testfirst.html

Why is this a useful way to start?
● New apps are not re-deployed, the machines simply move inventory location
● tests have already run many times
● Testing and Governance work can be done in parallel to development tasks
● Development teams know right away if they broke something before and/or after !
● Ability to use TDD software concepts for hardware
● Infrastructure can contain a version with matching tests

T.D.D. concepts for Infrastructure
To truly do Incremental Infrastructure delivery, we must
have an automated way to know that we haven’t broken
something else in the system when we make changes.
The key is finding a method to allow constant evolution of
our code base (infrastructure).
We do not need to reinvent an approach. Test Driven
Development concepts have proven effective in
incremental software delivery and can be re-used
effectively for infrastructure as code..
Mike Caspar, 2016

Git Repository for Sample Project
Sample project file(s) available here…
https://github.com/MikeCaspar/ansibleFest2016SFO
Mike Caspar, 2016

Mike Caspar
Incremental Infrastructure Coach
Enterprise agile Coach
email: mike@caspar.com
twitter: @mikecaspar
blog: http://mike-
caspar.blogspot.com

Testing for infrastructure as code for AnsibleFest 2016

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