From Chef Summit 2013

1. Chef Dialects
Noah Kantrowitz
Balanced, Inc

2. 10KM View
• Hooks to load from non-.rb
Improvements to layout
•

3. Dialect Hooks
• Recipes
Attributes
•
Metadata
•
• Roles
• Data bags

4. Rules
•
Side effect based
•
Ruby classes
•
File extension, MIME type

5. Cookbook Dialects
•
• depends 'dialect-js'
attributes/default.yml
•
• recipes/default.js
Distributed as cookbooks

6. dialect-js
template('/tmp/foo', {
source: 'foo.erb',
owner: 'root',
variables: {msg: node.msg}
})

7. dialect-py
import chef
chef.template('/tmp/foo',
source='foo.erb',
owner='root',
variables={'msg':'Hello'}
)

8. Knife Dialects
• Distributed as gems, knife plugins
• gem install knife-dialect-erbyaml
• knife role from file web.yml
• knife data bag from file users jdoe.yml

9. Current Dialects
• Javascript, based on therubyracer/V8
• Python, incomplete, based on ffi + libpython
• JSON
• YAML and ERB+YAML
• ...

10. Current Dialects
• Javascript, based on therubyracer/V8
• Python, incomplete, based on ffi + libpython
• JSON
• YAML and ERB+YAML
• Puppet (soon)

11. Next steps
• chef_fs for knife upload and chef-client -z
• More dialects
• Perl?
• Java?
• TOML?
• Templates?

12. Layout Shortcuts
• attributes/default.rb ➡ attributes.rb
• recipes/default.js ➡ recipe.js
• libraries/default.rb ➡ library.rb

13. RIP Specificity
• templates/foo.erb
files/foo.ini
•

14. Default lookup
• source 'foo.erb'
• host-fqdn/foo.erb
• platform-version/foo.erb
• platform/foo.erb
• default/foo.erb
• foo.erb ☺☺☺

15. Explicit Lookup
• source ['one.erb', 'two.erb']
• source [
"host-#{node['fqdn']}/name",
"#{node['platform']}-#{node['platform_version']}/name",
"#{node['platform']}/name",
"default/name",
]

16. Putting It All Together
my-postgresql/
attributes.json
metadata.yml
recipe.py
templates/
postgresql.conf.erb

17. When?
• github.com/coderanger/chef/tree/dialects
• Chef 12?