How to deploy your application like TripleO does.

1. how to use TripleO
tools for your own
project
Gonéri Le Bouder
Software Engineer
November 3, 2014

2. Myself
● Work @ eNovance, Paris office
● Long term Free Software contributor
● OpenStack contributor since 2013
● blablabla

3. OpenStack and TripleO

4. TripleO
OpenStack On OpenStack
Goal:
Deploy a fully functional OpenStack from a
minimal OpenStack

5. TripleO tool collection
TripleO uses or reuse various OpenStack tools:
● Heat
● Ironic and Nova Bare-metal
● DiskImage Builder (aka DIB) and some
image elements
● os-{apply,collect,refresh}-config
● probably some more

6. Heat
An API on rule them all
Describe an infrastructure and inject it in your
OpenStack tenant (VM, disk, autoscaling, etc)

7. DiskImage Builder
The gold image generator
A tool to generate image:
● Very modular
● Easy to extend using “elements”

8. DiskImage Builder
An DIB element is a set of files:
● Adjust the image content
● Install packages in the image
● Configuration file templates
● Configuration scripts.
Element can depend on another element (e.g:
fedora depends on yum)

9. DiskImage Builder
● fedora: the root element
● vm: will ensure we generate a VM image
● myapplication: will install the application itself
and the configuration template

10. os-{apply,collect,refresh}-config
Super light configuration management tool
1)Retrieve values from the meta servers
2)Pass them through configuration template
3)Apply the configuration

11. os-{apply,collect,refresh}-config
Source: https://wiki.openstack.org/wiki/OsCollectConfig

12. Configuration management:
A New Paradigm

13. common Paradigm
● Boot your machine with a very standard
Operating System
– Cloud image
– Distro installed with a Kickstart or a preseed
● Run a configuration management tools
– pull packages and resources from the network
– apply configuration
– Keep the OS up to date

14. Tripleo (and eDeploy) Paradigm
● Prepare some specialized images
● Use them to boot the machines (VM or bare-metal)
● Apply the configuration, without external
network access

15. The big changes
● The CM tool should not install package by itself
● The CM tool should only adjust the
configuration

16. Example

17. example
Configuration of Wordpress and MariaDB on two
dedicated nodes
https://github.com/enovance/wordpress-the-triple
o-way

18. the image
./elements/wordpress/install.d/10-wordpress
#!/bin/bash
set -eux
set -o xtrace
set -o pipefail
install-packages wordpress

19. the image
./elements/wordpress/os-apply-config/
etc/wordpress/wp-config.php (fragment)
<?php
define('DB_NAME', '{{wordpress.db_name}}');
define('DB_USER', '{{wordpress.db_user}}');
define('DB_PASSWORD', '{{wordpress.db_password}}');
define('DB_HOST', '{{wordpress.db_host}}');
define('DB_CHARSET', 'utf8');
define('DB_COLLATE', '');
etc

20. the image
./elements/wordpress/os-refresh-config/
configure.d/20-httpd
#!/bin/bash
set -eux
os-svc-enable -n httpd
if service httpd status; then
service httpd reload
else
service httpd restart
fi

21. heat
Heat file (fragment)
WordpressConfig:
type: OS::Heat::StructuredConfig
properties:
group: os-apply-config
config:
wordpress:
db_name: wordpress
db_password:
{get_resource:Wordpress_db_password}
db_host: {get_attr: [Mariadb, first_address]}
Etc ...

22. Benefits

23. Pros
Way easier to redeploy the application
● grab the images
● call heat, it will
– Deploy the infrastructure
– Export the meta-data for os-collect-config

24. Pros
Reduce the risk of failure
● Images + the meta data from heat should be
enough to get the application running

25. Pros
Super fast
● Start the machines from the images
● Pass the meta data through the templates
● Write the configuration

26. Pros
Consum less resources
● I/O: no package installation
● CPU: configuration only do the bare minimum

27. Not the perfect solution

28. The elements
● No repository with shared DIB “elements” yet
● OpenStack Heat and os-*-config evolve quickly,
the use of an up to date OpenStack release is a
must (for the moment)

29. Data
You need a strategy for your data storage
● TripleO use NFS here
● eNovance eDeploy use another upgrade
mechanism