Salt Formulas and States

This talk discusses how to begin creating and using Salt formulas and states to create modular, extensible, and clear content that others can use and learn from.

Transcript

1. Salt Formulas and States Forrest Alvarez
3. Formulas are the evolution of Salt states, they are the future of Salt.
4. Salt States Core of Salt Range from basic to very complex Used for provisioning and deployment
5. States Refresher Syntax is fairly simple Modular focus Ease of use
6. Example State nginx: pkg: - installed service: - running - enable: True - reload: True
7. State Directory Structure /srv/salt/nginx/init.sls - Installs and starts service /srv/salt/mysql/client.sls - installs client /srv/salt/mysql/server.sls - installs the server and starts the service
8. Salt States Can Become Complex apache: pkg: - installed {% if grains[‘os_family’] == ‘RedHat’ %} - name: httpd {% elif grains[‘os_family’] == ‘Debian’ %} - name: apache2 {% endif %}
9. Pillar Exploitation OS variables that shouldn’t be in pillar are Pillar becomes bloated Harder to understand for new users
10. Combine pillar and state complexity
11. Complexity leads to problems Different operating systems Multiple locations in a state Several states require changes
12. How Do We Address This? Ease of use Simple to modify multiple locations Can be applied to existing configurations
13. Salt Formulas Evolution of the Salt states Easy to write because you already are Somewhat difficult to understand how they work
14. Formula Directory Structure /srv/salt/apache/init.sls /srv/salt/apache/conf.sls /srv/salt/apache/map.jinja
15. The Core of Formulas, map.jinja Sets data based on OS grains Merges with Pillar data Centralizes variables
16. Creating The Map {% set apache = salt[‘grains.filter_by’]({ ‘Debian’: { ‘server’: ‘apache2’, ‘service’: ‘apache2’, ‘conf’: ‘/etc/apache2/apache.conf’, }, ‘RedHat’: { ‘server’: ‘httpd’, ‘service’: ‘httpd’, ‘conf’: ‘/etc/httpd/httpd.conf’, }, }, merge=salt[‘pillar.get’](‘apache:lookup’)) %}
17. Using Maps in States {% from “apache/map.jinja” import apache with context %} apache: pkg: - installed - name: {{ apache.server }} service: - running - name: {{ apache.service }} - enable: True
18. Before apache: pkg: - installed {% if grains[‘os_family’] == ‘RedHat’ %} - name: httpd {% elif grains[‘os_family’] == ‘Debian’ %} - name: apache2 {% endif %} service: - running {% if grains[‘os_family’] == ‘RedHat’ %} - name: httpd {% elif grains[‘os_family’] == ‘Debian’ %} - name: apache2 {% endif %} - enable: True
19. After {% from “apache/map.jinja” import apache with context %} apache: pkg: - installed - name: {{ apache.server }} service: - running - name: {{ apache.service }} - enable: True
20. A Few Seconds After That
21. More Maps in States {% from “apache/map.jinja” import apache with context %} include: - apache apache_conf: file: - managed - name: {{ apache.conf }} - source: {{ salt[‘pillar.get’](‘apache:lookup:config:tmpl’) }} # Notice this variable doesn’t live in our map - template: jinja - user: root - group: root - mode: ‘0644’ - watch_in: - service: apache
22. Pillars Splitting pillar data Identifying it with sets of states Will all be combined in the end
23. Pillar Directory Structure /srv/pillar/top.sls /srv/pillar/apache.sls /srv/pillar/php.sls
24. The Pillar Top.sls base: ‘*’: - apache - php
25. Extending Your Pillar apache: lookup: config: tmpl: salt://apache/files/redhat/httpd.conf
26. Merging Maps With Pillars Multiple pillars further reduce complexity Easy to include several pillars in your top pillar Pillar variables can overwrite map
27. Overwriting Maps apache: lookup: config: tmpl: salt://apache/files/redhat/ server: my_custom_apache
28. Clear Location of Variables Where did I miss that conf name change? Did I make sure to update all my requires? Hey, could you modify this value?
29. The Simpler the Better Works great even if you only have a single OS Easy to hand off Fewer files to manage
31. Managing Formulas Directory structure is the same as always One map file per formula Pillars are just included in your top pillar
32. Creating a Formula map.jinja Example Pillar Modular structure
33. Writing Formulas Effectively Think about what is OS based Consider what might need to be expanded Look at how someone else would see your formula
34. Premade Salt Formulas Over 75 formulas publicly available Not all formulas require the map Fork it with GIT and modify as needed
35. Contributing Back Fork an existing repo Ask for a repo to be made Contact the members
36. IRC: forrest Twitter: failvarez GitHub: gravyboat Questions?
37. Sources XKCD: Kayak comic - http://xkcd.com/209/ Easy button - http://dealer-communications.com/wp-content/uploads/2014/01/easy_button.png Bad cabling - http://farm3.staticflickr.com/2353/2219131561_31feee1745.jpg Earl of Lemongrab - http://fc03.deviantart.net/fs70/i/2013/108/e/3/lemongrab_by_twillis-d6266g9.png Dat Map - http://cdn.memegenerator.net/instances/500x/43904408.jpg Bruce Lee - http://www.elliottcaras.com/wp-content/uploads/2013/11/Bruce-Lee-Simplicity-is-the-key-2-brilliance.jpg Structure of Salt - http://upload.wikimedia.org/wikipedia/commons/2/29/NaCl.png Github OctoCat - http://www.iconsdb.com/icons/download/black/github-10-512.png